1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 #include <stdio.h> 39 #include <string.h> 40 #include <inttypes.h> 41 42 #include "ble/le_device_db.h" 43 #include "ble/core.h" 44 #include "ble/sm.h" 45 #include "btstack_debug.h" 46 #include "btstack_event.h" 47 #include "btstack_linked_list.h" 48 #include "btstack_memory.h" 49 #include "gap.h" 50 #include "hci.h" 51 #include "l2cap.h" 52 53 #ifdef ENABLE_LE_SECURE_CONNECTIONS 54 #ifdef HAVE_HCI_CONTROLLER_DHKEY_SUPPORT 55 #error "Support for DHKEY Support in HCI Controller not implemented yet. Please use software implementation" 56 #else 57 #define USE_MBEDTLS_FOR_ECDH 58 #endif 59 #endif 60 61 62 // Software ECDH implementation provided by mbedtls 63 #ifdef USE_MBEDTLS_FOR_ECDH 64 #include "mbedtls/config.h" 65 #include "mbedtls/platform.h" 66 #include "mbedtls/ecp.h" 67 #include "sm_mbedtls_allocator.h" 68 #endif 69 70 // 71 // SM internal types and globals 72 // 73 74 typedef enum { 75 DKG_W4_WORKING, 76 DKG_CALC_IRK, 77 DKG_W4_IRK, 78 DKG_CALC_DHK, 79 DKG_W4_DHK, 80 DKG_READY 81 } derived_key_generation_t; 82 83 typedef enum { 84 RAU_W4_WORKING, 85 RAU_IDLE, 86 RAU_GET_RANDOM, 87 RAU_W4_RANDOM, 88 RAU_GET_ENC, 89 RAU_W4_ENC, 90 RAU_SET_ADDRESS, 91 } random_address_update_t; 92 93 typedef enum { 94 CMAC_IDLE, 95 CMAC_CALC_SUBKEYS, 96 CMAC_W4_SUBKEYS, 97 CMAC_CALC_MI, 98 CMAC_W4_MI, 99 CMAC_CALC_MLAST, 100 CMAC_W4_MLAST 101 } cmac_state_t; 102 103 typedef enum { 104 JUST_WORKS, 105 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 106 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 107 OK_BOTH_INPUT, // Only input on both, both input PK 108 NK_BOTH_INPUT, // Only numerical compparison (yes/no) on on both sides 109 OOB // OOB available on both sides 110 } stk_generation_method_t; 111 112 typedef enum { 113 SM_USER_RESPONSE_IDLE, 114 SM_USER_RESPONSE_PENDING, 115 SM_USER_RESPONSE_CONFIRM, 116 SM_USER_RESPONSE_PASSKEY, 117 SM_USER_RESPONSE_DECLINE 118 } sm_user_response_t; 119 120 typedef enum { 121 SM_AES128_IDLE, 122 SM_AES128_ACTIVE 123 } sm_aes128_state_t; 124 125 typedef enum { 126 ADDRESS_RESOLUTION_IDLE, 127 ADDRESS_RESOLUTION_GENERAL, 128 ADDRESS_RESOLUTION_FOR_CONNECTION, 129 } address_resolution_mode_t; 130 131 typedef enum { 132 ADDRESS_RESOLUTION_SUCEEDED, 133 ADDRESS_RESOLUTION_FAILED, 134 } address_resolution_event_t; 135 136 typedef enum { 137 EC_KEY_GENERATION_IDLE, 138 EC_KEY_GENERATION_ACTIVE, 139 EC_KEY_GENERATION_DONE, 140 } ec_key_generation_state_t; 141 142 typedef enum { 143 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 0 144 } sm_state_var_t; 145 146 // 147 // GLOBAL DATA 148 // 149 150 static uint8_t test_use_fixed_local_csrk; 151 152 // configuration 153 static uint8_t sm_accepted_stk_generation_methods; 154 static uint8_t sm_max_encryption_key_size; 155 static uint8_t sm_min_encryption_key_size; 156 static uint8_t sm_auth_req = 0; 157 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 158 static uint8_t sm_slave_request_security; 159 static uint8_t sm_have_ec_keypair; 160 161 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 162 static sm_key_t sm_persistent_er; 163 static sm_key_t sm_persistent_ir; 164 165 // derived from sm_persistent_ir 166 static sm_key_t sm_persistent_dhk; 167 static sm_key_t sm_persistent_irk; 168 static uint8_t sm_persistent_irk_ready = 0; // used for testing 169 static derived_key_generation_t dkg_state; 170 171 // derived from sm_persistent_er 172 // .. 173 174 // random address update 175 static random_address_update_t rau_state; 176 static bd_addr_t sm_random_address; 177 178 // CMAC Calculation: General 179 static cmac_state_t sm_cmac_state; 180 static uint16_t sm_cmac_message_len; 181 static sm_key_t sm_cmac_k; 182 static sm_key_t sm_cmac_x; 183 static sm_key_t sm_cmac_m_last; 184 static uint8_t sm_cmac_block_current; 185 static uint8_t sm_cmac_block_count; 186 static uint8_t (*sm_cmac_get_byte)(uint16_t offset); 187 static void (*sm_cmac_done_handler)(uint8_t * hash); 188 189 // CMAC for ATT Signed Writes 190 static uint8_t sm_cmac_header[3]; 191 static const uint8_t * sm_cmac_message; 192 static uint8_t sm_cmac_sign_counter[4]; 193 194 // CMAC for Secure Connection functions 195 #ifdef ENABLE_LE_SECURE_CONNECTIONS 196 static sm_connection_t * sm_cmac_connection; 197 static uint8_t sm_cmac_sc_buffer[80]; 198 #endif 199 200 // resolvable private address lookup / CSRK calculation 201 static int sm_address_resolution_test; 202 static int sm_address_resolution_ah_calculation_active; 203 static uint8_t sm_address_resolution_addr_type; 204 static bd_addr_t sm_address_resolution_address; 205 static void * sm_address_resolution_context; 206 static address_resolution_mode_t sm_address_resolution_mode; 207 static btstack_linked_list_t sm_address_resolution_general_queue; 208 209 // aes128 crypto engine. store current sm_connection_t in sm_aes128_context 210 static sm_aes128_state_t sm_aes128_state; 211 static void * sm_aes128_context; 212 213 // random engine. store context (ususally sm_connection_t) 214 static void * sm_random_context; 215 216 // to receive hci events 217 static btstack_packet_callback_registration_t hci_event_callback_registration; 218 219 /* to dispatch sm event */ 220 static btstack_linked_list_t sm_event_handlers; 221 222 223 // Software ECDH implementation provided by mbedtls 224 #ifdef USE_MBEDTLS_FOR_ECDH 225 // group is always valid 226 static mbedtls_ecp_group mbedtls_ec_group; 227 static ec_key_generation_state_t ec_key_generation_state; 228 static uint8_t ec_qx[32]; 229 static uint8_t ec_qy[32]; 230 static uint8_t ec_d[32]; 231 #ifndef HAVE_MALLOC 232 #ifdef ENABLE_FIXED_LE_EC_KEY 233 // 232 bytes with 6 allocations 234 #define MBEDTLS_ALLOC_BUFFER_SIZE (250+6*sizeof(void *)) 235 #else 236 // 4304 bytes with 73 allocations 237 #define MBEDTLS_ALLOC_BUFFER_SIZE (4400+73*sizeof(void *)) 238 #endif 239 static uint8_t mbedtls_memory_buffer[MBEDTLS_ALLOC_BUFFER_SIZE]; 240 #endif 241 #endif 242 243 // 244 // Volume 3, Part H, Chapter 24 245 // "Security shall be initiated by the Security Manager in the device in the master role. 246 // The device in the slave role shall be the responding device." 247 // -> master := initiator, slave := responder 248 // 249 250 // data needed for security setup 251 typedef struct sm_setup_context { 252 253 btstack_timer_source_t sm_timeout; 254 255 // used in all phases 256 uint8_t sm_pairing_failed_reason; 257 258 // user response, (Phase 1 and/or 2) 259 uint8_t sm_user_response; 260 261 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 262 int sm_key_distribution_send_set; 263 int sm_key_distribution_received_set; 264 265 // Phase 2 (Pairing over SMP) 266 stk_generation_method_t sm_stk_generation_method; 267 sm_key_t sm_tk; 268 uint8_t sm_use_secure_connections; 269 270 sm_key_t sm_c1_t3_value; // c1 calculation 271 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 272 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 273 sm_key_t sm_local_random; 274 sm_key_t sm_local_confirm; 275 sm_key_t sm_peer_random; 276 sm_key_t sm_peer_confirm; 277 uint8_t sm_m_addr_type; // address and type can be removed 278 uint8_t sm_s_addr_type; // '' 279 bd_addr_t sm_m_address; // '' 280 bd_addr_t sm_s_address; // '' 281 sm_key_t sm_ltk; 282 283 uint8_t sm_state_vars; 284 #ifdef ENABLE_LE_SECURE_CONNECTIONS 285 uint8_t sm_peer_qx[32]; // also stores random for EC key generation during init 286 uint8_t sm_peer_qy[32]; // '' 287 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 288 sm_key_t sm_local_nonce; // might be combined with sm_local_random 289 sm_key_t sm_peer_dhkey_check; 290 sm_key_t sm_local_dhkey_check; 291 sm_key_t sm_ra; 292 sm_key_t sm_rb; 293 sm_key_t sm_t; // used for f5 294 sm_key_t sm_mackey; 295 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 296 #endif 297 298 // Phase 3 299 300 // key distribution, we generate 301 uint16_t sm_local_y; 302 uint16_t sm_local_div; 303 uint16_t sm_local_ediv; 304 uint8_t sm_local_rand[8]; 305 sm_key_t sm_local_ltk; 306 sm_key_t sm_local_csrk; 307 sm_key_t sm_local_irk; 308 // sm_local_address/addr_type not needed 309 310 // key distribution, received from peer 311 uint16_t sm_peer_y; 312 uint16_t sm_peer_div; 313 uint16_t sm_peer_ediv; 314 uint8_t sm_peer_rand[8]; 315 sm_key_t sm_peer_ltk; 316 sm_key_t sm_peer_irk; 317 sm_key_t sm_peer_csrk; 318 uint8_t sm_peer_addr_type; 319 bd_addr_t sm_peer_address; 320 321 } sm_setup_context_t; 322 323 // 324 static sm_setup_context_t the_setup; 325 static sm_setup_context_t * setup = &the_setup; 326 327 // active connection - the one for which the_setup is used for 328 static uint16_t sm_active_connection = 0; 329 330 // @returns 1 if oob data is available 331 // stores oob data in provided 16 byte buffer if not null 332 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 333 334 // used to notify applicationss that user interaction is neccessary, see sm_notify_t below 335 static btstack_packet_handler_t sm_client_packet_handler = NULL; 336 337 // horizontal: initiator capabilities 338 // vertial: responder capabilities 339 static const stk_generation_method_t stk_generation_method [5] [5] = { 340 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 341 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 342 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 343 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 344 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 345 }; 346 347 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 348 #ifdef ENABLE_LE_SECURE_CONNECTIONS 349 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 350 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 351 { JUST_WORKS, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 352 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 353 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 354 { PK_RESP_INPUT, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 355 }; 356 #endif 357 358 static void sm_run(void); 359 static void sm_done_for_handle(hci_con_handle_t con_handle); 360 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 361 static inline int sm_calc_actual_encryption_key_size(int other); 362 static int sm_validate_stk_generation_method(void); 363 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data); 364 365 static void log_info_hex16(const char * name, uint16_t value){ 366 log_info("%-6s 0x%04x", name, value); 367 } 368 369 // @returns 1 if all bytes are 0 370 static int sm_is_null(uint8_t * data, int size){ 371 int i; 372 for (i=0; i < size ; i++){ 373 if (data[i]) return 0; 374 } 375 return 1; 376 } 377 378 static int sm_is_null_random(uint8_t random[8]){ 379 return sm_is_null(random, 8); 380 } 381 382 static int sm_is_null_key(uint8_t * key){ 383 return sm_is_null(key, 16); 384 } 385 386 // Key utils 387 static void sm_reset_tk(void){ 388 int i; 389 for (i=0;i<16;i++){ 390 setup->sm_tk[i] = 0; 391 } 392 } 393 394 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 395 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 396 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 397 int i; 398 for (i = max_encryption_size ; i < 16 ; i++){ 399 key[15-i] = 0; 400 } 401 } 402 403 // SMP Timeout implementation 404 405 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 406 // the Security Manager Timer shall be reset and started. 407 // 408 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 409 // 410 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 411 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 412 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 413 // established. 414 415 static void sm_timeout_handler(btstack_timer_source_t * timer){ 416 log_info("SM timeout"); 417 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 418 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 419 sm_done_for_handle(sm_conn->sm_handle); 420 421 // trigger handling of next ready connection 422 sm_run(); 423 } 424 static void sm_timeout_start(sm_connection_t * sm_conn){ 425 btstack_run_loop_remove_timer(&setup->sm_timeout); 426 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 427 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 428 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 429 btstack_run_loop_add_timer(&setup->sm_timeout); 430 } 431 static void sm_timeout_stop(void){ 432 btstack_run_loop_remove_timer(&setup->sm_timeout); 433 } 434 static void sm_timeout_reset(sm_connection_t * sm_conn){ 435 sm_timeout_stop(); 436 sm_timeout_start(sm_conn); 437 } 438 439 // end of sm timeout 440 441 // GAP Random Address updates 442 static gap_random_address_type_t gap_random_adress_type; 443 static btstack_timer_source_t gap_random_address_update_timer; 444 static uint32_t gap_random_adress_update_period; 445 446 static void gap_random_address_trigger(void){ 447 if (rau_state != RAU_IDLE) return; 448 log_info("gap_random_address_trigger"); 449 rau_state = RAU_GET_RANDOM; 450 sm_run(); 451 } 452 453 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 454 log_info("GAP Random Address Update due"); 455 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 456 btstack_run_loop_add_timer(&gap_random_address_update_timer); 457 gap_random_address_trigger(); 458 } 459 460 static void gap_random_address_update_start(void){ 461 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 462 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 463 btstack_run_loop_add_timer(&gap_random_address_update_timer); 464 } 465 466 static void gap_random_address_update_stop(void){ 467 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 468 } 469 470 471 static void sm_random_start(void * context){ 472 sm_random_context = context; 473 hci_send_cmd(&hci_le_rand); 474 } 475 476 // pre: sm_aes128_state != SM_AES128_ACTIVE, hci_can_send_command == 1 477 // context is made availabe to aes128 result handler by this 478 static void sm_aes128_start(sm_key_t key, sm_key_t plaintext, void * context){ 479 sm_aes128_state = SM_AES128_ACTIVE; 480 sm_key_t key_flipped, plaintext_flipped; 481 reverse_128(key, key_flipped); 482 reverse_128(plaintext, plaintext_flipped); 483 sm_aes128_context = context; 484 hci_send_cmd(&hci_le_encrypt, key_flipped, plaintext_flipped); 485 } 486 487 // ah(k,r) helper 488 // r = padding || r 489 // r - 24 bit value 490 static void sm_ah_r_prime(uint8_t r[3], sm_key_t r_prime){ 491 // r'= padding || r 492 memset(r_prime, 0, 16); 493 memcpy(&r_prime[13], r, 3); 494 } 495 496 // d1 helper 497 // d' = padding || r || d 498 // d,r - 16 bit values 499 static void sm_d1_d_prime(uint16_t d, uint16_t r, sm_key_t d1_prime){ 500 // d'= padding || r || d 501 memset(d1_prime, 0, 16); 502 big_endian_store_16(d1_prime, 12, r); 503 big_endian_store_16(d1_prime, 14, d); 504 } 505 506 // dm helper 507 // r’ = padding || r 508 // r - 64 bit value 509 static void sm_dm_r_prime(uint8_t r[8], sm_key_t r_prime){ 510 memset(r_prime, 0, 16); 511 memcpy(&r_prime[8], r, 8); 512 } 513 514 // calculate arguments for first AES128 operation in C1 function 515 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){ 516 517 // p1 = pres || preq || rat’ || iat’ 518 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 519 // cant octet of pres becomes the most significant octet of p1. 520 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 521 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 522 // p1 is 0x05000800000302070710000001010001." 523 524 sm_key_t p1; 525 reverse_56(pres, &p1[0]); 526 reverse_56(preq, &p1[7]); 527 p1[14] = rat; 528 p1[15] = iat; 529 log_info_key("p1", p1); 530 log_info_key("r", r); 531 532 // t1 = r xor p1 533 int i; 534 for (i=0;i<16;i++){ 535 t1[i] = r[i] ^ p1[i]; 536 } 537 log_info_key("t1", t1); 538 } 539 540 // calculate arguments for second AES128 operation in C1 function 541 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, sm_key_t t3){ 542 // p2 = padding || ia || ra 543 // "The least significant octet of ra becomes the least significant octet of p2 and 544 // the most significant octet of padding becomes the most significant octet of p2. 545 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 546 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 547 548 sm_key_t p2; 549 memset(p2, 0, 16); 550 memcpy(&p2[4], ia, 6); 551 memcpy(&p2[10], ra, 6); 552 log_info_key("p2", p2); 553 554 // c1 = e(k, t2_xor_p2) 555 int i; 556 for (i=0;i<16;i++){ 557 t3[i] = t2[i] ^ p2[i]; 558 } 559 log_info_key("t3", t3); 560 } 561 562 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, sm_key_t r_prime){ 563 log_info_key("r1", r1); 564 log_info_key("r2", r2); 565 memcpy(&r_prime[8], &r2[8], 8); 566 memcpy(&r_prime[0], &r1[8], 8); 567 } 568 569 #ifdef ENABLE_LE_SECURE_CONNECTIONS 570 // Software implementations of crypto toolbox for LE Secure Connection 571 // TODO: replace with code to use AES Engine of HCI Controller 572 typedef uint8_t sm_key24_t[3]; 573 typedef uint8_t sm_key56_t[7]; 574 typedef uint8_t sm_key256_t[32]; 575 576 #if 0 577 static void aes128_calc_cyphertext(const uint8_t key[16], const uint8_t plaintext[16], uint8_t cyphertext[16]){ 578 uint32_t rk[RKLENGTH(KEYBITS)]; 579 int nrounds = rijndaelSetupEncrypt(rk, &key[0], KEYBITS); 580 rijndaelEncrypt(rk, nrounds, plaintext, cyphertext); 581 } 582 583 static void calc_subkeys(sm_key_t k0, sm_key_t k1, sm_key_t k2){ 584 memcpy(k1, k0, 16); 585 sm_shift_left_by_one_bit_inplace(16, k1); 586 if (k0[0] & 0x80){ 587 k1[15] ^= 0x87; 588 } 589 memcpy(k2, k1, 16); 590 sm_shift_left_by_one_bit_inplace(16, k2); 591 if (k1[0] & 0x80){ 592 k2[15] ^= 0x87; 593 } 594 } 595 596 static void aes_cmac(sm_key_t aes_cmac, const sm_key_t key, const uint8_t * data, int cmac_message_len){ 597 sm_key_t k0, k1, k2, zero; 598 memset(zero, 0, 16); 599 600 aes128_calc_cyphertext(key, zero, k0); 601 calc_subkeys(k0, k1, k2); 602 603 int cmac_block_count = (cmac_message_len + 15) / 16; 604 605 // step 3: .. 606 if (cmac_block_count==0){ 607 cmac_block_count = 1; 608 } 609 610 // step 4: set m_last 611 sm_key_t cmac_m_last; 612 int sm_cmac_last_block_complete = cmac_message_len != 0 && (cmac_message_len & 0x0f) == 0; 613 int i; 614 if (sm_cmac_last_block_complete){ 615 for (i=0;i<16;i++){ 616 cmac_m_last[i] = data[cmac_message_len - 16 + i] ^ k1[i]; 617 } 618 } else { 619 int valid_octets_in_last_block = cmac_message_len & 0x0f; 620 for (i=0;i<16;i++){ 621 if (i < valid_octets_in_last_block){ 622 cmac_m_last[i] = data[(cmac_message_len & 0xfff0) + i] ^ k2[i]; 623 continue; 624 } 625 if (i == valid_octets_in_last_block){ 626 cmac_m_last[i] = 0x80 ^ k2[i]; 627 continue; 628 } 629 cmac_m_last[i] = k2[i]; 630 } 631 } 632 633 // printf("sm_cmac_start: len %u, block count %u\n", cmac_message_len, cmac_block_count); 634 // LOG_KEY(cmac_m_last); 635 636 // Step 5 637 sm_key_t cmac_x; 638 memset(cmac_x, 0, 16); 639 640 // Step 6 641 sm_key_t sm_cmac_y; 642 for (int block = 0 ; block < cmac_block_count-1 ; block++){ 643 for (i=0;i<16;i++){ 644 sm_cmac_y[i] = cmac_x[i] ^ data[block * 16 + i]; 645 } 646 aes128_calc_cyphertext(key, sm_cmac_y, cmac_x); 647 } 648 for (i=0;i<16;i++){ 649 sm_cmac_y[i] = cmac_x[i] ^ cmac_m_last[i]; 650 } 651 652 // Step 7 653 aes128_calc_cyphertext(key, sm_cmac_y, aes_cmac); 654 } 655 #endif 656 657 #if 0 658 // 659 // Link Key Conversion Function h6 660 // 661 // h6(W, keyID) = AES-CMACW(keyID) 662 // - W is 128 bits 663 // - keyID is 32 bits 664 static void h6(sm_key_t res, const sm_key_t w, const uint32_t key_id){ 665 uint8_t key_id_buffer[4]; 666 big_endian_store_32(key_id_buffer, 0, key_id); 667 aes_cmac(res, w, key_id_buffer, 4); 668 } 669 #endif 670 #endif 671 672 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){ 673 event[0] = type; 674 event[1] = event_size - 2; 675 little_endian_store_16(event, 2, con_handle); 676 event[4] = addr_type; 677 reverse_bd_addr(address, &event[5]); 678 } 679 680 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 681 if (sm_client_packet_handler) { 682 sm_client_packet_handler(HCI_EVENT_PACKET, 0, packet, size); 683 } 684 // dispatch to all event handlers 685 btstack_linked_list_iterator_t it; 686 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 687 while (btstack_linked_list_iterator_has_next(&it)){ 688 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 689 entry->callback(packet_type, 0, packet, size); 690 } 691 } 692 693 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 694 uint8_t event[11]; 695 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 696 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 697 } 698 699 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){ 700 uint8_t event[15]; 701 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 702 little_endian_store_32(event, 11, passkey); 703 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 704 } 705 706 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){ 707 uint8_t event[13]; 708 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 709 little_endian_store_16(event, 11, index); 710 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 711 } 712 713 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){ 714 715 uint8_t event[18]; 716 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 717 event[11] = result; 718 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 719 } 720 721 // decide on stk generation based on 722 // - pairing request 723 // - io capabilities 724 // - OOB data availability 725 static void sm_setup_tk(void){ 726 727 // default: just works 728 setup->sm_stk_generation_method = JUST_WORKS; 729 730 #ifdef ENABLE_LE_SECURE_CONNECTIONS 731 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 732 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 733 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 734 memset(setup->sm_ra, 0, 16); 735 memset(setup->sm_rb, 0, 16); 736 #else 737 setup->sm_use_secure_connections = 0; 738 #endif 739 740 // If both devices have not set the MITM option in the Authentication Requirements 741 // Flags, then the IO capabilities shall be ignored and the Just Works association 742 // model shall be used. 743 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 744 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 745 log_info("SM: MITM not required by both -> JUST WORKS"); 746 return; 747 } 748 749 // TODO: with LE SC, OOB is used to transfer data OOB during pairing, single device with OOB is sufficient 750 751 // If both devices have out of band authentication data, then the Authentication 752 // Requirements Flags shall be ignored when selecting the pairing method and the 753 // Out of Band pairing method shall be used. 754 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) 755 && sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)){ 756 log_info("SM: have OOB data"); 757 log_info_key("OOB", setup->sm_tk); 758 setup->sm_stk_generation_method = OOB; 759 return; 760 } 761 762 // Reset TK as it has been setup in sm_init_setup 763 sm_reset_tk(); 764 765 // Also use just works if unknown io capabilites 766 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)){ 767 return; 768 } 769 770 // Otherwise the IO capabilities of the devices shall be used to determine the 771 // pairing method as defined in Table 2.4. 772 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 773 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 774 775 #ifdef ENABLE_LE_SECURE_CONNECTIONS 776 // table not define by default 777 if (setup->sm_use_secure_connections){ 778 generation_method = stk_generation_method_with_secure_connection; 779 } 780 #endif 781 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)]; 782 783 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 784 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); 785 } 786 787 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 788 int flags = 0; 789 if (key_set & SM_KEYDIST_ENC_KEY){ 790 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 791 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 792 } 793 if (key_set & SM_KEYDIST_ID_KEY){ 794 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 795 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 796 } 797 if (key_set & SM_KEYDIST_SIGN){ 798 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 799 } 800 return flags; 801 } 802 803 static void sm_setup_key_distribution(uint8_t key_set){ 804 setup->sm_key_distribution_received_set = 0; 805 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 806 } 807 808 // CSRK Key Lookup 809 810 811 static int sm_address_resolution_idle(void){ 812 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 813 } 814 815 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){ 816 memcpy(sm_address_resolution_address, addr, 6); 817 sm_address_resolution_addr_type = addr_type; 818 sm_address_resolution_test = 0; 819 sm_address_resolution_mode = mode; 820 sm_address_resolution_context = context; 821 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 822 } 823 824 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 825 // check if already in list 826 btstack_linked_list_iterator_t it; 827 sm_lookup_entry_t * entry; 828 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 829 while(btstack_linked_list_iterator_has_next(&it)){ 830 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 831 if (entry->address_type != address_type) continue; 832 if (memcmp(entry->address, address, 6)) continue; 833 // already in list 834 return BTSTACK_BUSY; 835 } 836 entry = btstack_memory_sm_lookup_entry_get(); 837 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 838 entry->address_type = (bd_addr_type_t) address_type; 839 memcpy(entry->address, address, 6); 840 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 841 sm_run(); 842 return 0; 843 } 844 845 // CMAC Implementation using AES128 engine 846 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 847 int i; 848 int carry = 0; 849 for (i=len-1; i >= 0 ; i--){ 850 int new_carry = data[i] >> 7; 851 data[i] = data[i] << 1 | carry; 852 carry = new_carry; 853 } 854 } 855 856 // 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 857 static inline void sm_next_responding_state(sm_connection_t * sm_conn){ 858 sm_conn->sm_engine_state = (security_manager_state_t) (((int)sm_conn->sm_engine_state) + 1); 859 } 860 static inline void dkg_next_state(void){ 861 dkg_state = (derived_key_generation_t) (((int)dkg_state) + 1); 862 } 863 static inline void rau_next_state(void){ 864 rau_state = (random_address_update_t) (((int)rau_state) + 1); 865 } 866 867 // CMAC calculation using AES Engine 868 869 static inline void sm_cmac_next_state(void){ 870 sm_cmac_state = (cmac_state_t) (((int)sm_cmac_state) + 1); 871 } 872 873 static int sm_cmac_last_block_complete(void){ 874 if (sm_cmac_message_len == 0) return 0; 875 return (sm_cmac_message_len & 0x0f) == 0; 876 } 877 878 static inline uint8_t sm_cmac_message_get_byte(uint16_t offset){ 879 if (offset >= sm_cmac_message_len) { 880 log_error("sm_cmac_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_message_len); 881 return 0; 882 } 883 884 offset = sm_cmac_message_len - 1 - offset; 885 886 // sm_cmac_header[3] | message[] | sm_cmac_sign_counter[4] 887 if (offset < 3){ 888 return sm_cmac_header[offset]; 889 } 890 int actual_message_len_incl_header = sm_cmac_message_len - 4; 891 if (offset < actual_message_len_incl_header){ 892 return sm_cmac_message[offset - 3]; 893 } 894 return sm_cmac_sign_counter[offset - actual_message_len_incl_header]; 895 } 896 897 // generic cmac calculation 898 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])){ 899 // Generalized CMAC 900 memcpy(sm_cmac_k, key, 16); 901 memset(sm_cmac_x, 0, 16); 902 sm_cmac_block_current = 0; 903 sm_cmac_message_len = message_len; 904 sm_cmac_done_handler = done_callback; 905 sm_cmac_get_byte = get_byte_callback; 906 907 // step 2: n := ceil(len/const_Bsize); 908 sm_cmac_block_count = (sm_cmac_message_len + 15) / 16; 909 910 // step 3: .. 911 if (sm_cmac_block_count==0){ 912 sm_cmac_block_count = 1; 913 } 914 log_info("sm_cmac_general_start: len %u, block count %u", sm_cmac_message_len, sm_cmac_block_count); 915 916 // first, we need to compute l for k1, k2, and m_last 917 sm_cmac_state = CMAC_CALC_SUBKEYS; 918 919 // let's go 920 sm_run(); 921 } 922 923 // cmac for ATT Message signing 924 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)){ 925 // ATT Message Signing 926 sm_cmac_header[0] = opcode; 927 little_endian_store_16(sm_cmac_header, 1, con_handle); 928 little_endian_store_32(sm_cmac_sign_counter, 0, sign_counter); 929 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 930 sm_cmac_message = message; 931 sm_cmac_general_start(k, total_message_len, &sm_cmac_message_get_byte, done_handler); 932 } 933 934 int sm_cmac_ready(void){ 935 return sm_cmac_state == CMAC_IDLE; 936 } 937 938 static void sm_cmac_handle_aes_engine_ready(void){ 939 switch (sm_cmac_state){ 940 case CMAC_CALC_SUBKEYS: { 941 sm_key_t const_zero; 942 memset(const_zero, 0, 16); 943 sm_cmac_next_state(); 944 sm_aes128_start(sm_cmac_k, const_zero, NULL); 945 break; 946 } 947 case CMAC_CALC_MI: { 948 int j; 949 sm_key_t y; 950 for (j=0;j<16;j++){ 951 y[j] = sm_cmac_x[j] ^ sm_cmac_get_byte(sm_cmac_block_current*16 + j); 952 } 953 sm_cmac_block_current++; 954 sm_cmac_next_state(); 955 sm_aes128_start(sm_cmac_k, y, NULL); 956 break; 957 } 958 case CMAC_CALC_MLAST: { 959 int i; 960 sm_key_t y; 961 for (i=0;i<16;i++){ 962 y[i] = sm_cmac_x[i] ^ sm_cmac_m_last[i]; 963 } 964 log_info_key("Y", y); 965 sm_cmac_block_current++; 966 sm_cmac_next_state(); 967 sm_aes128_start(sm_cmac_k, y, NULL); 968 break; 969 } 970 default: 971 log_info("sm_cmac_handle_aes_engine_ready called in state %u", sm_cmac_state); 972 break; 973 } 974 } 975 976 static void sm_cmac_handle_encryption_result(sm_key_t data){ 977 switch (sm_cmac_state){ 978 case CMAC_W4_SUBKEYS: { 979 sm_key_t k1; 980 memcpy(k1, data, 16); 981 sm_shift_left_by_one_bit_inplace(16, k1); 982 if (data[0] & 0x80){ 983 k1[15] ^= 0x87; 984 } 985 sm_key_t k2; 986 memcpy(k2, k1, 16); 987 sm_shift_left_by_one_bit_inplace(16, k2); 988 if (k1[0] & 0x80){ 989 k2[15] ^= 0x87; 990 } 991 992 log_info_key("k", sm_cmac_k); 993 log_info_key("k1", k1); 994 log_info_key("k2", k2); 995 996 // step 4: set m_last 997 int i; 998 if (sm_cmac_last_block_complete()){ 999 for (i=0;i<16;i++){ 1000 sm_cmac_m_last[i] = sm_cmac_get_byte(sm_cmac_message_len - 16 + i) ^ k1[i]; 1001 } 1002 } else { 1003 int valid_octets_in_last_block = sm_cmac_message_len & 0x0f; 1004 for (i=0;i<16;i++){ 1005 if (i < valid_octets_in_last_block){ 1006 sm_cmac_m_last[i] = sm_cmac_get_byte((sm_cmac_message_len & 0xfff0) + i) ^ k2[i]; 1007 continue; 1008 } 1009 if (i == valid_octets_in_last_block){ 1010 sm_cmac_m_last[i] = 0x80 ^ k2[i]; 1011 continue; 1012 } 1013 sm_cmac_m_last[i] = k2[i]; 1014 } 1015 } 1016 1017 // next 1018 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1019 break; 1020 } 1021 case CMAC_W4_MI: 1022 memcpy(sm_cmac_x, data, 16); 1023 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1024 break; 1025 case CMAC_W4_MLAST: 1026 // done 1027 log_info("Setting CMAC Engine to IDLE"); 1028 sm_cmac_state = CMAC_IDLE; 1029 log_info_key("CMAC", data); 1030 sm_cmac_done_handler(data); 1031 break; 1032 default: 1033 log_info("sm_cmac_handle_encryption_result called in state %u", sm_cmac_state); 1034 break; 1035 } 1036 } 1037 1038 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 1039 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 1040 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 1041 switch (setup->sm_stk_generation_method){ 1042 case PK_RESP_INPUT: 1043 if (sm_conn->sm_role){ 1044 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1045 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1046 } else { 1047 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)); 1048 } 1049 break; 1050 case PK_INIT_INPUT: 1051 if (sm_conn->sm_role){ 1052 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)); 1053 } else { 1054 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1055 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1056 } 1057 break; 1058 case OK_BOTH_INPUT: 1059 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1060 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1061 break; 1062 case NK_BOTH_INPUT: 1063 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1064 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)); 1065 break; 1066 case JUST_WORKS: 1067 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1068 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1069 break; 1070 case OOB: 1071 // client already provided OOB data, let's skip notification. 1072 break; 1073 } 1074 } 1075 1076 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 1077 int recv_flags; 1078 if (sm_conn->sm_role){ 1079 // slave / responder 1080 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 1081 } else { 1082 // master / initiator 1083 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 1084 } 1085 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1086 return recv_flags == setup->sm_key_distribution_received_set; 1087 } 1088 1089 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1090 if (sm_active_connection == con_handle){ 1091 sm_timeout_stop(); 1092 sm_active_connection = 0; 1093 log_info("sm: connection 0x%x released setup context", con_handle); 1094 } 1095 } 1096 1097 static int sm_key_distribution_flags_for_auth_req(void){ 1098 int flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_SIGN; 1099 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1100 // encryption information only if bonding requested 1101 flags |= SM_KEYDIST_ENC_KEY; 1102 } 1103 return flags; 1104 } 1105 1106 static void sm_init_setup(sm_connection_t * sm_conn){ 1107 1108 // fill in sm setup 1109 setup->sm_state_vars = 0; 1110 sm_reset_tk(); 1111 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1112 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1113 1114 // query client for OOB data 1115 int have_oob_data = 0; 1116 if (sm_get_oob_data) { 1117 have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1118 } 1119 1120 sm_pairing_packet_t * local_packet; 1121 if (sm_conn->sm_role){ 1122 // slave 1123 local_packet = &setup->sm_s_pres; 1124 gap_advertisements_get_address(&setup->sm_s_addr_type, setup->sm_s_address); 1125 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1126 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1127 } else { 1128 // master 1129 local_packet = &setup->sm_m_preq; 1130 gap_advertisements_get_address(&setup->sm_m_addr_type, setup->sm_m_address); 1131 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1132 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1133 1134 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1135 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1136 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1137 } 1138 1139 uint8_t auth_req = sm_auth_req; 1140 #ifdef ENABLE_FIXED_LE_EC_KEY 1141 if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 1142 if (!sm_have_ec_keypair){ 1143 log_error("sm: disablling secure connection as key generation disabled but no fixed key provided."); 1144 auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; 1145 } 1146 } 1147 #endif 1148 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1149 sm_pairing_packet_set_oob_data_flag(*local_packet, have_oob_data); 1150 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1151 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1152 } 1153 1154 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1155 1156 sm_pairing_packet_t * remote_packet; 1157 int remote_key_request; 1158 if (sm_conn->sm_role){ 1159 // slave / responder 1160 remote_packet = &setup->sm_m_preq; 1161 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1162 } else { 1163 // master / initiator 1164 remote_packet = &setup->sm_s_pres; 1165 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1166 } 1167 1168 // check key size 1169 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1170 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1171 1172 // decide on STK generation method 1173 sm_setup_tk(); 1174 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1175 1176 // check if STK generation method is acceptable by client 1177 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1178 1179 // identical to responder 1180 sm_setup_key_distribution(remote_key_request); 1181 1182 // JUST WORKS doens't provide authentication 1183 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1184 1185 return 0; 1186 } 1187 1188 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1189 1190 // cache and reset context 1191 int matched_device_id = sm_address_resolution_test; 1192 address_resolution_mode_t mode = sm_address_resolution_mode; 1193 void * context = sm_address_resolution_context; 1194 1195 // reset context 1196 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1197 sm_address_resolution_context = NULL; 1198 sm_address_resolution_test = -1; 1199 hci_con_handle_t con_handle = 0; 1200 1201 sm_connection_t * sm_connection; 1202 uint16_t ediv; 1203 switch (mode){ 1204 case ADDRESS_RESOLUTION_GENERAL: 1205 break; 1206 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1207 sm_connection = (sm_connection_t *) context; 1208 con_handle = sm_connection->sm_handle; 1209 switch (event){ 1210 case ADDRESS_RESOLUTION_SUCEEDED: 1211 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1212 sm_connection->sm_le_db_index = matched_device_id; 1213 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1214 if (sm_connection->sm_role) break; 1215 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1216 sm_connection->sm_security_request_received = 0; 1217 sm_connection->sm_bonding_requested = 0; 1218 le_device_db_encryption_get(sm_connection->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 1219 if (ediv){ 1220 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1221 } else { 1222 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1223 } 1224 break; 1225 case ADDRESS_RESOLUTION_FAILED: 1226 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1227 if (sm_connection->sm_role) break; 1228 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1229 sm_connection->sm_security_request_received = 0; 1230 sm_connection->sm_bonding_requested = 0; 1231 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1232 break; 1233 } 1234 break; 1235 default: 1236 break; 1237 } 1238 1239 switch (event){ 1240 case ADDRESS_RESOLUTION_SUCEEDED: 1241 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1242 break; 1243 case ADDRESS_RESOLUTION_FAILED: 1244 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1245 break; 1246 } 1247 } 1248 1249 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1250 1251 int le_db_index = -1; 1252 1253 // lookup device based on IRK 1254 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1255 int i; 1256 for (i=0; i < le_device_db_count(); i++){ 1257 sm_key_t irk; 1258 bd_addr_t address; 1259 int address_type; 1260 le_device_db_info(i, &address_type, address, irk); 1261 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1262 log_info("sm: device found for IRK, updating"); 1263 le_db_index = i; 1264 break; 1265 } 1266 } 1267 } 1268 1269 // if not found, lookup via public address if possible 1270 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1271 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1272 int i; 1273 for (i=0; i < le_device_db_count(); i++){ 1274 bd_addr_t address; 1275 int address_type; 1276 le_device_db_info(i, &address_type, address, NULL); 1277 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1278 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1279 log_info("sm: device found for public address, updating"); 1280 le_db_index = i; 1281 break; 1282 } 1283 } 1284 } 1285 1286 // if not found, add to db 1287 if (le_db_index < 0) { 1288 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1289 } 1290 1291 if (le_db_index >= 0){ 1292 le_device_db_local_counter_set(le_db_index, 0); 1293 1294 // store local CSRK 1295 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1296 log_info("sm: store local CSRK"); 1297 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1298 le_device_db_local_counter_set(le_db_index, 0); 1299 } 1300 1301 // store remote CSRK 1302 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1303 log_info("sm: store remote CSRK"); 1304 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1305 le_device_db_remote_counter_set(le_db_index, 0); 1306 } 1307 1308 // store encryption information 1309 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION 1310 && setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 1311 log_info("sm: set encryption information (key size %u, authenticatd %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1312 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1313 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1314 } 1315 } 1316 1317 // keep le_db_index 1318 sm_conn->sm_le_db_index = le_db_index; 1319 } 1320 1321 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1322 setup->sm_pairing_failed_reason = reason; 1323 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1324 } 1325 1326 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1327 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1328 } 1329 1330 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1331 1332 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1333 static int sm_passkey_used(stk_generation_method_t method); 1334 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1335 1336 static void sm_log_ec_keypair(void){ 1337 log_info("d: %s", ec_d); 1338 log_info("X: %s", ec_qx); 1339 log_info("Y: %s", ec_qy); 1340 } 1341 1342 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1343 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1344 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1345 } else { 1346 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1347 } 1348 } 1349 1350 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1351 if (sm_conn->sm_role){ 1352 // Responder 1353 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1354 } else { 1355 // Initiator role 1356 switch (setup->sm_stk_generation_method){ 1357 case JUST_WORKS: 1358 sm_sc_prepare_dhkey_check(sm_conn); 1359 break; 1360 1361 case NK_BOTH_INPUT: 1362 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1363 break; 1364 case PK_INIT_INPUT: 1365 case PK_RESP_INPUT: 1366 case OK_BOTH_INPUT: 1367 if (setup->sm_passkey_bit < 20) { 1368 sm_sc_start_calculating_local_confirm(sm_conn); 1369 } else { 1370 sm_sc_prepare_dhkey_check(sm_conn); 1371 } 1372 break; 1373 case OOB: 1374 // TODO: implement SC OOB 1375 break; 1376 } 1377 } 1378 } 1379 1380 static uint8_t sm_sc_cmac_get_byte(uint16_t offset){ 1381 return sm_cmac_sc_buffer[offset]; 1382 } 1383 1384 static void sm_sc_cmac_done(uint8_t * hash){ 1385 log_info("sm_sc_cmac_done: "); 1386 log_info_hexdump(hash, 16); 1387 1388 sm_connection_t * sm_conn = sm_cmac_connection; 1389 sm_cmac_connection = NULL; 1390 1391 switch (sm_conn->sm_engine_state){ 1392 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1393 memcpy(setup->sm_local_confirm, hash, 16); 1394 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1395 break; 1396 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1397 // check 1398 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1399 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1400 break; 1401 } 1402 sm_sc_state_after_receiving_random(sm_conn); 1403 break; 1404 case SM_SC_W4_CALCULATE_G2: { 1405 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1406 big_endian_store_32(setup->sm_tk, 12, vab); 1407 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1408 sm_trigger_user_response(sm_conn); 1409 break; 1410 } 1411 case SM_SC_W4_CALCULATE_F5_SALT: 1412 memcpy(setup->sm_t, hash, 16); 1413 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1414 break; 1415 case SM_SC_W4_CALCULATE_F5_MACKEY: 1416 memcpy(setup->sm_mackey, hash, 16); 1417 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1418 break; 1419 case SM_SC_W4_CALCULATE_F5_LTK: 1420 memcpy(setup->sm_ltk, hash, 16); 1421 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1422 break; 1423 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1424 memcpy(setup->sm_local_dhkey_check, hash, 16); 1425 if (sm_conn->sm_role){ 1426 // responder 1427 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1428 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1429 } else { 1430 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1431 } 1432 } else { 1433 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1434 } 1435 break; 1436 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1437 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1438 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1439 break; 1440 } 1441 if (sm_conn->sm_role){ 1442 // responder 1443 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1444 } else { 1445 // initiator 1446 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1447 } 1448 break; 1449 default: 1450 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1451 break; 1452 } 1453 sm_run(); 1454 } 1455 1456 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){ 1457 const uint16_t message_len = 65; 1458 sm_cmac_connection = sm_conn; 1459 memcpy(sm_cmac_sc_buffer, u, 32); 1460 memcpy(sm_cmac_sc_buffer+32, v, 32); 1461 sm_cmac_sc_buffer[64] = z; 1462 log_info("f4 key"); 1463 log_info_hexdump(x, 16); 1464 log_info("f4 message"); 1465 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1466 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1467 } 1468 1469 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1470 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1471 static const uint8_t f5_length[] = { 0x01, 0x00}; 1472 1473 static void sm_sc_calculate_dhkey(sm_key256_t dhkey){ 1474 #ifdef USE_MBEDTLS_FOR_ECDH 1475 // da * Pb 1476 mbedtls_mpi d; 1477 mbedtls_ecp_point Q; 1478 mbedtls_ecp_point DH; 1479 mbedtls_mpi_init(&d); 1480 mbedtls_ecp_point_init(&Q); 1481 mbedtls_ecp_point_init(&DH); 1482 mbedtls_mpi_read_binary(&d, ec_d, 32); 1483 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 1484 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 1485 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 1486 mbedtls_ecp_mul(&mbedtls_ec_group, &DH, &d, &Q, NULL, NULL); 1487 mbedtls_mpi_write_binary(&DH.X, dhkey, 32); 1488 mbedtls_mpi_free(&d); 1489 mbedtls_ecp_point_free(&Q); 1490 mbedtls_ecp_point_free(&DH); 1491 #endif 1492 log_info("dhkey"); 1493 log_info_hexdump(dhkey, 32); 1494 } 1495 1496 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1497 // calculate DHKEY 1498 sm_key256_t dhkey; 1499 sm_sc_calculate_dhkey(dhkey); 1500 1501 // calculate salt for f5 1502 const uint16_t message_len = 32; 1503 sm_cmac_connection = sm_conn; 1504 memcpy(sm_cmac_sc_buffer, dhkey, message_len); 1505 sm_cmac_general_start(f5_salt, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1506 } 1507 1508 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){ 1509 const uint16_t message_len = 53; 1510 sm_cmac_connection = sm_conn; 1511 1512 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1513 sm_cmac_sc_buffer[0] = 0; 1514 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1515 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1516 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1517 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1518 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1519 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1520 log_info("f5 key"); 1521 log_info_hexdump(t, 16); 1522 log_info("f5 message for MacKey"); 1523 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1524 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1525 } 1526 1527 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1528 sm_key56_t bd_addr_master, bd_addr_slave; 1529 bd_addr_master[0] = setup->sm_m_addr_type; 1530 bd_addr_slave[0] = setup->sm_s_addr_type; 1531 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1532 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1533 if (sm_conn->sm_role){ 1534 // responder 1535 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1536 } else { 1537 // initiator 1538 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1539 } 1540 } 1541 1542 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1543 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1544 const uint16_t message_len = 53; 1545 sm_cmac_connection = sm_conn; 1546 sm_cmac_sc_buffer[0] = 1; 1547 // 1..52 setup before 1548 log_info("f5 key"); 1549 log_info_hexdump(t, 16); 1550 log_info("f5 message for LTK"); 1551 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1552 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1553 } 1554 1555 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1556 f5_ltk(sm_conn, setup->sm_t); 1557 } 1558 1559 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){ 1560 const uint16_t message_len = 65; 1561 sm_cmac_connection = sm_conn; 1562 memcpy(sm_cmac_sc_buffer, n1, 16); 1563 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1564 memcpy(sm_cmac_sc_buffer+32, r, 16); 1565 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1566 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1567 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1568 log_info("f6 key"); 1569 log_info_hexdump(w, 16); 1570 log_info("f6 message"); 1571 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1572 sm_cmac_general_start(w, 65, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1573 } 1574 1575 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1576 // - U is 256 bits 1577 // - V is 256 bits 1578 // - X is 128 bits 1579 // - Y is 128 bits 1580 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){ 1581 const uint16_t message_len = 80; 1582 sm_cmac_connection = sm_conn; 1583 memcpy(sm_cmac_sc_buffer, u, 32); 1584 memcpy(sm_cmac_sc_buffer+32, v, 32); 1585 memcpy(sm_cmac_sc_buffer+64, y, 16); 1586 log_info("g2 key"); 1587 log_info_hexdump(x, 16); 1588 log_info("g2 message"); 1589 log_info_hexdump(sm_cmac_sc_buffer, sizeof(sm_cmac_sc_buffer)); 1590 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1591 } 1592 1593 static void g2_calculate(sm_connection_t * sm_conn) { 1594 // calc Va if numeric comparison 1595 if (sm_conn->sm_role){ 1596 // responder 1597 g2_engine(sm_conn, setup->sm_peer_qx, ec_qx, setup->sm_peer_nonce, setup->sm_local_nonce);; 1598 } else { 1599 // initiator 1600 g2_engine(sm_conn, ec_qx, setup->sm_peer_qx, setup->sm_local_nonce, setup->sm_peer_nonce); 1601 } 1602 } 1603 1604 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1605 uint8_t z = 0; 1606 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1607 // some form of passkey 1608 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1609 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1610 setup->sm_passkey_bit++; 1611 } 1612 f4_engine(sm_conn, ec_qx, setup->sm_peer_qx, setup->sm_local_nonce, z); 1613 } 1614 1615 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1616 uint8_t z = 0; 1617 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1618 // some form of passkey 1619 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1620 // sm_passkey_bit was increased before sending confirm value 1621 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1622 } 1623 f4_engine(sm_conn, setup->sm_peer_qx, ec_qx, setup->sm_peer_nonce, z); 1624 } 1625 1626 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1627 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1628 } 1629 1630 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1631 // calculate DHKCheck 1632 sm_key56_t bd_addr_master, bd_addr_slave; 1633 bd_addr_master[0] = setup->sm_m_addr_type; 1634 bd_addr_slave[0] = setup->sm_s_addr_type; 1635 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1636 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1637 uint8_t iocap_a[3]; 1638 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1639 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1640 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1641 uint8_t iocap_b[3]; 1642 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1643 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1644 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1645 if (sm_conn->sm_role){ 1646 // responder 1647 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); 1648 } else { 1649 // initiator 1650 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); 1651 } 1652 } 1653 1654 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1655 // validate E = f6() 1656 sm_key56_t bd_addr_master, bd_addr_slave; 1657 bd_addr_master[0] = setup->sm_m_addr_type; 1658 bd_addr_slave[0] = setup->sm_s_addr_type; 1659 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1660 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1661 1662 uint8_t iocap_a[3]; 1663 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1664 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1665 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1666 uint8_t iocap_b[3]; 1667 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1668 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1669 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1670 if (sm_conn->sm_role){ 1671 // responder 1672 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); 1673 } else { 1674 // initiator 1675 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); 1676 } 1677 } 1678 #endif 1679 1680 static void sm_load_security_info(sm_connection_t * sm_connection){ 1681 int encryption_key_size; 1682 int authenticated; 1683 int authorized; 1684 1685 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1686 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1687 &encryption_key_size, &authenticated, &authorized); 1688 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1689 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1690 sm_connection->sm_connection_authenticated = authenticated; 1691 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1692 } 1693 1694 static void sm_run(void){ 1695 1696 btstack_linked_list_iterator_t it; 1697 1698 // assert that we can send at least commands 1699 if (!hci_can_send_command_packet_now()) return; 1700 1701 // 1702 // non-connection related behaviour 1703 // 1704 1705 // distributed key generation 1706 switch (dkg_state){ 1707 case DKG_CALC_IRK: 1708 // already busy? 1709 if (sm_aes128_state == SM_AES128_IDLE) { 1710 // IRK = d1(IR, 1, 0) 1711 sm_key_t d1_prime; 1712 sm_d1_d_prime(1, 0, d1_prime); // plaintext 1713 dkg_next_state(); 1714 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1715 return; 1716 } 1717 break; 1718 case DKG_CALC_DHK: 1719 // already busy? 1720 if (sm_aes128_state == SM_AES128_IDLE) { 1721 // DHK = d1(IR, 3, 0) 1722 sm_key_t d1_prime; 1723 sm_d1_d_prime(3, 0, d1_prime); // plaintext 1724 dkg_next_state(); 1725 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1726 return; 1727 } 1728 break; 1729 default: 1730 break; 1731 } 1732 1733 #ifdef USE_MBEDTLS_FOR_ECDH 1734 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 1735 sm_random_start(NULL); 1736 return; 1737 } 1738 #endif 1739 1740 // random address updates 1741 switch (rau_state){ 1742 case RAU_GET_RANDOM: 1743 rau_next_state(); 1744 sm_random_start(NULL); 1745 return; 1746 case RAU_GET_ENC: 1747 // already busy? 1748 if (sm_aes128_state == SM_AES128_IDLE) { 1749 sm_key_t r_prime; 1750 sm_ah_r_prime(sm_random_address, r_prime); 1751 rau_next_state(); 1752 sm_aes128_start(sm_persistent_irk, r_prime, NULL); 1753 return; 1754 } 1755 break; 1756 case RAU_SET_ADDRESS: 1757 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1758 rau_state = RAU_IDLE; 1759 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1760 return; 1761 default: 1762 break; 1763 } 1764 1765 // CMAC 1766 switch (sm_cmac_state){ 1767 case CMAC_CALC_SUBKEYS: 1768 case CMAC_CALC_MI: 1769 case CMAC_CALC_MLAST: 1770 // already busy? 1771 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1772 sm_cmac_handle_aes_engine_ready(); 1773 return; 1774 default: 1775 break; 1776 } 1777 1778 // CSRK Lookup 1779 // -- if csrk lookup ready, find connection that require csrk lookup 1780 if (sm_address_resolution_idle()){ 1781 hci_connections_get_iterator(&it); 1782 while(btstack_linked_list_iterator_has_next(&it)){ 1783 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1784 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1785 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1786 // and start lookup 1787 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); 1788 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1789 break; 1790 } 1791 } 1792 } 1793 1794 // -- if csrk lookup ready, resolved addresses for received addresses 1795 if (sm_address_resolution_idle()) { 1796 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1797 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1798 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1799 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1800 btstack_memory_sm_lookup_entry_free(entry); 1801 } 1802 } 1803 1804 // -- Continue with CSRK device lookup by public or resolvable private address 1805 if (!sm_address_resolution_idle()){ 1806 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_count()); 1807 while (sm_address_resolution_test < le_device_db_count()){ 1808 int addr_type; 1809 bd_addr_t addr; 1810 sm_key_t irk; 1811 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1812 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1813 1814 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1815 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1816 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1817 break; 1818 } 1819 1820 if (sm_address_resolution_addr_type == 0){ 1821 sm_address_resolution_test++; 1822 continue; 1823 } 1824 1825 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1826 1827 log_info("LE Device Lookup: calculate AH"); 1828 log_info_key("IRK", irk); 1829 1830 sm_key_t r_prime; 1831 sm_ah_r_prime(sm_address_resolution_address, r_prime); 1832 sm_address_resolution_ah_calculation_active = 1; 1833 sm_aes128_start(irk, r_prime, sm_address_resolution_context); // keep context 1834 return; 1835 } 1836 1837 if (sm_address_resolution_test >= le_device_db_count()){ 1838 log_info("LE Device Lookup: not found"); 1839 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1840 } 1841 } 1842 1843 1844 // 1845 // active connection handling 1846 // -- use loop to handle next connection if lock on setup context is released 1847 1848 while (1) { 1849 1850 // Find connections that requires setup context and make active if no other is locked 1851 hci_connections_get_iterator(&it); 1852 while(!sm_active_connection && btstack_linked_list_iterator_has_next(&it)){ 1853 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1854 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1855 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 1856 int done = 1; 1857 int err; 1858 switch (sm_connection->sm_engine_state) { 1859 case SM_RESPONDER_SEND_SECURITY_REQUEST: 1860 // send packet if possible, 1861 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 1862 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 1863 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 1864 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1865 } else { 1866 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1867 } 1868 // don't lock sxetup context yet 1869 done = 0; 1870 break; 1871 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 1872 sm_init_setup(sm_connection); 1873 // recover pairing request 1874 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 1875 err = sm_stk_generation_init(sm_connection); 1876 if (err){ 1877 setup->sm_pairing_failed_reason = err; 1878 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1879 break; 1880 } 1881 sm_timeout_start(sm_connection); 1882 // generate random number first, if we need to show passkey 1883 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 1884 sm_connection->sm_engine_state = SM_PH2_GET_RANDOM_TK; 1885 break; 1886 } 1887 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 1888 break; 1889 case SM_INITIATOR_PH0_HAS_LTK: 1890 sm_load_security_info(sm_connection); 1891 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 1892 break; 1893 case SM_RESPONDER_PH0_RECEIVED_LTK: 1894 switch (sm_connection->sm_irk_lookup_state){ 1895 case IRK_LOOKUP_SUCCEEDED:{ 1896 sm_load_security_info(sm_connection); 1897 sm_connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 1898 break; 1899 } 1900 case IRK_LOOKUP_FAILED: 1901 // assume that we don't have a LTK for ediv == 0 and random == null 1902 if (sm_connection->sm_local_ediv == 0 && sm_is_null_random(sm_connection->sm_local_rand)){ 1903 log_info("LTK Request: ediv & random are empty"); 1904 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1905 // TODO: no need to lock context yet -> done = 0; 1906 break; 1907 } 1908 // re-establish previously used LTK using Rand and EDIV 1909 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1910 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1911 // re-establish used key encryption size 1912 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1913 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1914 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1915 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1916 log_info("sm: received ltk request with key size %u, authenticated %u", 1917 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1918 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1919 break; 1920 default: 1921 // just wait until IRK lookup is completed 1922 // don't lock sxetup context yet 1923 done = 0; 1924 break; 1925 } 1926 break; 1927 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 1928 sm_init_setup(sm_connection); 1929 sm_timeout_start(sm_connection); 1930 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 1931 break; 1932 default: 1933 done = 0; 1934 break; 1935 } 1936 if (done){ 1937 sm_active_connection = sm_connection->sm_handle; 1938 log_info("sm: connection 0x%04x locked setup context as %s", sm_active_connection, sm_connection->sm_role ? "responder" : "initiator"); 1939 } 1940 } 1941 1942 // 1943 // active connection handling 1944 // 1945 1946 if (sm_active_connection == 0) return; 1947 1948 // assert that we could send a SM PDU - not needed for all of the following 1949 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 1950 l2cap_request_can_send_fix_channel_now_event(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1951 return; 1952 } 1953 1954 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection); 1955 if (!connection) return; 1956 1957 sm_key_t plaintext; 1958 int key_distribution_flags; 1959 1960 log_info("sm_run: state %u", connection->sm_engine_state); 1961 1962 // responding state 1963 switch (connection->sm_engine_state){ 1964 1965 // general 1966 case SM_GENERAL_SEND_PAIRING_FAILED: { 1967 uint8_t buffer[2]; 1968 buffer[0] = SM_CODE_PAIRING_FAILED; 1969 buffer[1] = setup->sm_pairing_failed_reason; 1970 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 1971 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1972 sm_done_for_handle(connection->sm_handle); 1973 break; 1974 } 1975 1976 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1977 case SM_SC_W2_GET_RANDOM_A: 1978 sm_random_start(connection); 1979 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_A; 1980 break; 1981 case SM_SC_W2_GET_RANDOM_B: 1982 sm_random_start(connection); 1983 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_B; 1984 break; 1985 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 1986 if (!sm_cmac_ready()) break; 1987 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 1988 sm_sc_calculate_local_confirm(connection); 1989 break; 1990 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 1991 if (!sm_cmac_ready()) break; 1992 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 1993 sm_sc_calculate_remote_confirm(connection); 1994 break; 1995 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 1996 if (!sm_cmac_ready()) break; 1997 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 1998 sm_sc_calculate_f6_for_dhkey_check(connection); 1999 break; 2000 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2001 if (!sm_cmac_ready()) break; 2002 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2003 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2004 break; 2005 case SM_SC_W2_CALCULATE_F5_SALT: 2006 if (!sm_cmac_ready()) break; 2007 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2008 f5_calculate_salt(connection); 2009 break; 2010 case SM_SC_W2_CALCULATE_F5_MACKEY: 2011 if (!sm_cmac_ready()) break; 2012 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2013 f5_calculate_mackey(connection); 2014 break; 2015 case SM_SC_W2_CALCULATE_F5_LTK: 2016 if (!sm_cmac_ready()) break; 2017 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2018 f5_calculate_ltk(connection); 2019 break; 2020 case SM_SC_W2_CALCULATE_G2: 2021 if (!sm_cmac_ready()) break; 2022 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2023 g2_calculate(connection); 2024 break; 2025 2026 #endif 2027 // initiator side 2028 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2029 sm_key_t peer_ltk_flipped; 2030 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2031 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2032 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2033 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2034 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2035 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2036 return; 2037 } 2038 2039 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2040 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2041 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2042 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2043 sm_timeout_reset(connection); 2044 break; 2045 2046 // responder side 2047 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2048 connection->sm_engine_state = SM_RESPONDER_IDLE; 2049 hci_send_cmd(&hci_le_long_term_key_negative_reply, connection->sm_handle); 2050 sm_done_for_handle(connection->sm_handle); 2051 return; 2052 2053 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2054 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2055 uint8_t buffer[65]; 2056 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2057 // 2058 reverse_256(ec_qx, &buffer[1]); 2059 reverse_256(ec_qy, &buffer[33]); 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 int sm_generate_f_rng(void * context, unsigned char * buffer, size_t size){ 2571 int offset = setup->sm_passkey_bit; 2572 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, offset); 2573 while (size) { 2574 if (offset < 32){ 2575 *buffer++ = setup->sm_peer_qx[offset++]; 2576 } else { 2577 *buffer++ = setup->sm_peer_qx[offset++ - 32]; 2578 } 2579 size--; 2580 } 2581 setup->sm_passkey_bit = offset; 2582 return 0; 2583 } 2584 #endif 2585 2586 // note: random generator is ready. this doesn NOT imply that aes engine is unused! 2587 static void sm_handle_random_result(uint8_t * data){ 2588 2589 #ifdef USE_MBEDTLS_FOR_ECDH 2590 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 2591 int num_bytes = setup->sm_passkey_bit; 2592 if (num_bytes < 32){ 2593 memcpy(&setup->sm_peer_qx[num_bytes], data, 8); 2594 } else { 2595 memcpy(&setup->sm_peer_qx[num_bytes-32], data, 8); 2596 } 2597 num_bytes += 8; 2598 setup->sm_passkey_bit = num_bytes; 2599 2600 if (num_bytes >= 64){ 2601 // generate EC key 2602 setup->sm_passkey_bit = 0; 2603 mbedtls_mpi d; 2604 mbedtls_ecp_point P; 2605 mbedtls_mpi_init(&d); 2606 mbedtls_ecp_point_init(&P); 2607 mbedtls_ecp_gen_keypair(&mbedtls_ec_group, &d, &P, &sm_generate_f_rng, NULL); 2608 mbedtls_mpi_write_binary(&P.X, ec_qx, 16); 2609 mbedtls_mpi_write_binary(&P.Y, ec_qy, 16); 2610 mbedtls_mpi_write_binary(&d, ec_d, 16); 2611 sm_log_ec_keypair(); 2612 mbedtls_ecp_point_free(&P); 2613 mbedtls_mpi_free(&d); 2614 ec_key_generation_state = EC_KEY_GENERATION_DONE; 2615 } 2616 } 2617 #endif 2618 2619 switch (rau_state){ 2620 case RAU_W4_RANDOM: 2621 // non-resolvable vs. resolvable 2622 switch (gap_random_adress_type){ 2623 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2624 // resolvable: use random as prand and calc address hash 2625 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2626 memcpy(sm_random_address, data, 3); 2627 sm_random_address[0] &= 0x3f; 2628 sm_random_address[0] |= 0x40; 2629 rau_state = RAU_GET_ENC; 2630 break; 2631 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2632 default: 2633 // "The two most significant bits of the address shall be equal to ‘0’"" 2634 memcpy(sm_random_address, data, 6); 2635 sm_random_address[0] &= 0x3f; 2636 rau_state = RAU_SET_ADDRESS; 2637 break; 2638 } 2639 return; 2640 default: 2641 break; 2642 } 2643 2644 // retrieve sm_connection provided to sm_random_start 2645 sm_connection_t * connection = (sm_connection_t *) sm_random_context; 2646 if (!connection) return; 2647 switch (connection->sm_engine_state){ 2648 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2649 case SM_SC_W4_GET_RANDOM_A: 2650 memcpy(&setup->sm_local_nonce[0], data, 8); 2651 connection->sm_engine_state = SM_SC_W2_GET_RANDOM_B; 2652 break; 2653 case SM_SC_W4_GET_RANDOM_B: 2654 memcpy(&setup->sm_local_nonce[8], data, 8); 2655 // initiator & jw/nc -> send pairing random 2656 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2657 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2658 break; 2659 } else { 2660 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2661 } 2662 break; 2663 #endif 2664 2665 case SM_PH2_W4_RANDOM_TK: 2666 { 2667 // map random to 0-999999 without speding much cycles on a modulus operation 2668 uint32_t tk = little_endian_read_32(data,0); 2669 tk = tk & 0xfffff; // 1048575 2670 if (tk >= 999999){ 2671 tk = tk - 999999; 2672 } 2673 sm_reset_tk(); 2674 big_endian_store_32(setup->sm_tk, 12, tk); 2675 if (connection->sm_role){ 2676 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2677 } else { 2678 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2679 sm_trigger_user_response(connection); 2680 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2681 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2682 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 2683 } 2684 } 2685 return; 2686 } 2687 case SM_PH2_C1_W4_RANDOM_A: 2688 memcpy(&setup->sm_local_random[0], data, 8); // random endinaness 2689 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_B; 2690 return; 2691 case SM_PH2_C1_W4_RANDOM_B: 2692 memcpy(&setup->sm_local_random[8], data, 8); // random endinaness 2693 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2694 return; 2695 case SM_PH3_W4_RANDOM: 2696 reverse_64(data, setup->sm_local_rand); 2697 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2698 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2699 // no db for authenticated flag hack: store flag in bit 4 of LSB 2700 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2701 connection->sm_engine_state = SM_PH3_GET_DIV; 2702 return; 2703 case SM_PH3_W4_DIV: 2704 // use 16 bit from random value as div 2705 setup->sm_local_div = big_endian_read_16(data, 0); 2706 log_info_hex16("div", setup->sm_local_div); 2707 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2708 return; 2709 default: 2710 break; 2711 } 2712 } 2713 2714 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2715 2716 sm_connection_t * sm_conn; 2717 hci_con_handle_t con_handle; 2718 2719 switch (packet_type) { 2720 2721 case HCI_EVENT_PACKET: 2722 switch (hci_event_packet_get_type(packet)) { 2723 2724 case BTSTACK_EVENT_STATE: 2725 // bt stack activated, get started 2726 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2727 log_info("HCI Working!"); 2728 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 2729 rau_state = RAU_IDLE; 2730 #ifdef USE_MBEDTLS_FOR_ECDH 2731 #ifndef ENABLE_FIXED_LE_EC_KEY 2732 if (!sm_have_ec_keypair){ 2733 setup->sm_passkey_bit = 0; 2734 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 2735 } 2736 #endif 2737 #endif 2738 sm_run(); 2739 } 2740 break; 2741 2742 case HCI_EVENT_LE_META: 2743 switch (packet[2]) { 2744 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2745 2746 log_info("sm: connected"); 2747 2748 if (packet[3]) return; // connection failed 2749 2750 con_handle = little_endian_read_16(packet, 4); 2751 sm_conn = sm_get_connection_for_handle(con_handle); 2752 if (!sm_conn) break; 2753 2754 sm_conn->sm_handle = con_handle; 2755 sm_conn->sm_role = packet[6]; 2756 sm_conn->sm_peer_addr_type = packet[7]; 2757 reverse_bd_addr(&packet[8], 2758 sm_conn->sm_peer_address); 2759 2760 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2761 2762 // reset security properties 2763 sm_conn->sm_connection_encrypted = 0; 2764 sm_conn->sm_connection_authenticated = 0; 2765 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2766 sm_conn->sm_le_db_index = -1; 2767 2768 // prepare CSRK lookup (does not involve setup) 2769 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2770 2771 // just connected -> everything else happens in sm_run() 2772 if (sm_conn->sm_role){ 2773 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2774 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2775 if (sm_slave_request_security) { 2776 // request security if requested by app 2777 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2778 } else { 2779 // otherwise, wait for pairing request 2780 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2781 } 2782 } 2783 break; 2784 } else { 2785 // master 2786 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2787 } 2788 break; 2789 2790 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2791 con_handle = little_endian_read_16(packet, 3); 2792 sm_conn = sm_get_connection_for_handle(con_handle); 2793 if (!sm_conn) break; 2794 2795 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2796 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2797 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2798 break; 2799 } 2800 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 2801 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2802 break; 2803 } 2804 2805 // store rand and ediv 2806 reverse_64(&packet[5], sm_conn->sm_local_rand); 2807 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2808 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK; 2809 break; 2810 2811 default: 2812 break; 2813 } 2814 break; 2815 2816 case HCI_EVENT_ENCRYPTION_CHANGE: 2817 con_handle = little_endian_read_16(packet, 3); 2818 sm_conn = sm_get_connection_for_handle(con_handle); 2819 if (!sm_conn) break; 2820 2821 sm_conn->sm_connection_encrypted = packet[5]; 2822 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 2823 sm_conn->sm_actual_encryption_key_size); 2824 log_info("event handler, state %u", sm_conn->sm_engine_state); 2825 if (!sm_conn->sm_connection_encrypted) break; 2826 // continue if part of initial pairing 2827 switch (sm_conn->sm_engine_state){ 2828 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2829 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2830 sm_done_for_handle(sm_conn->sm_handle); 2831 break; 2832 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2833 if (sm_conn->sm_role){ 2834 // slave 2835 if (setup->sm_use_secure_connections){ 2836 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2837 } else { 2838 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2839 } 2840 } else { 2841 // master 2842 if (sm_key_distribution_all_received(sm_conn)){ 2843 // skip receiving keys as there are none 2844 sm_key_distribution_handle_all_received(sm_conn); 2845 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2846 } else { 2847 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2848 } 2849 } 2850 break; 2851 default: 2852 break; 2853 } 2854 break; 2855 2856 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 2857 con_handle = little_endian_read_16(packet, 3); 2858 sm_conn = sm_get_connection_for_handle(con_handle); 2859 if (!sm_conn) break; 2860 2861 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 2862 log_info("event handler, state %u", sm_conn->sm_engine_state); 2863 // continue if part of initial pairing 2864 switch (sm_conn->sm_engine_state){ 2865 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2866 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2867 sm_done_for_handle(sm_conn->sm_handle); 2868 break; 2869 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2870 if (sm_conn->sm_role){ 2871 // slave 2872 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2873 } else { 2874 // master 2875 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2876 } 2877 break; 2878 default: 2879 break; 2880 } 2881 break; 2882 2883 2884 case HCI_EVENT_DISCONNECTION_COMPLETE: 2885 con_handle = little_endian_read_16(packet, 3); 2886 sm_done_for_handle(con_handle); 2887 sm_conn = sm_get_connection_for_handle(con_handle); 2888 if (!sm_conn) break; 2889 2890 // delete stored bonding on disconnect with authentication failure in ph0 2891 if (sm_conn->sm_role == 0 2892 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 2893 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 2894 le_device_db_remove(sm_conn->sm_le_db_index); 2895 } 2896 2897 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 2898 sm_conn->sm_handle = 0; 2899 break; 2900 2901 case HCI_EVENT_COMMAND_COMPLETE: 2902 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 2903 sm_handle_encryption_result(&packet[6]); 2904 break; 2905 } 2906 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 2907 sm_handle_random_result(&packet[6]); 2908 break; 2909 } 2910 break; 2911 default: 2912 break; 2913 } 2914 break; 2915 default: 2916 break; 2917 } 2918 2919 sm_run(); 2920 } 2921 2922 static inline int sm_calc_actual_encryption_key_size(int other){ 2923 if (other < sm_min_encryption_key_size) return 0; 2924 if (other < sm_max_encryption_key_size) return other; 2925 return sm_max_encryption_key_size; 2926 } 2927 2928 2929 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 2930 switch (method){ 2931 case JUST_WORKS: 2932 case NK_BOTH_INPUT: 2933 return 1; 2934 default: 2935 return 0; 2936 } 2937 } 2938 // responder 2939 2940 static int sm_passkey_used(stk_generation_method_t method){ 2941 switch (method){ 2942 case PK_RESP_INPUT: 2943 return 1; 2944 default: 2945 return 0; 2946 } 2947 } 2948 2949 /** 2950 * @return ok 2951 */ 2952 static int sm_validate_stk_generation_method(void){ 2953 // check if STK generation method is acceptable by client 2954 switch (setup->sm_stk_generation_method){ 2955 case JUST_WORKS: 2956 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 2957 case PK_RESP_INPUT: 2958 case PK_INIT_INPUT: 2959 case OK_BOTH_INPUT: 2960 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 2961 case OOB: 2962 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 2963 case NK_BOTH_INPUT: 2964 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 2965 return 1; 2966 default: 2967 return 0; 2968 } 2969 } 2970 2971 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 2972 2973 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 2974 sm_run(); 2975 } 2976 2977 if (packet_type != SM_DATA_PACKET) return; 2978 2979 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 2980 if (!sm_conn) return; 2981 2982 if (packet[0] == SM_CODE_PAIRING_FAILED){ 2983 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2984 return; 2985 } 2986 2987 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, packet[0]); 2988 2989 int err; 2990 2991 switch (sm_conn->sm_engine_state){ 2992 2993 // a sm timeout requries a new physical connection 2994 case SM_GENERAL_TIMEOUT: 2995 return; 2996 2997 // Initiator 2998 case SM_INITIATOR_CONNECTED: 2999 if ((packet[0] != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3000 sm_pdu_received_in_wrong_state(sm_conn); 3001 break; 3002 } 3003 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 3004 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3005 break; 3006 } 3007 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 3008 uint16_t ediv; 3009 sm_key_t ltk; 3010 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3011 if (!sm_is_null_key(ltk) || ediv){ 3012 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3013 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3014 } else { 3015 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3016 } 3017 break; 3018 } 3019 // otherwise, store security request 3020 sm_conn->sm_security_request_received = 1; 3021 break; 3022 3023 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3024 if (packet[0] != SM_CODE_PAIRING_RESPONSE){ 3025 sm_pdu_received_in_wrong_state(sm_conn); 3026 break; 3027 } 3028 // store pairing request 3029 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3030 err = sm_stk_generation_init(sm_conn); 3031 if (err){ 3032 setup->sm_pairing_failed_reason = err; 3033 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3034 break; 3035 } 3036 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3037 if (setup->sm_use_secure_connections){ 3038 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3039 if (setup->sm_stk_generation_method == JUST_WORKS){ 3040 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3041 sm_trigger_user_response(sm_conn); 3042 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3043 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3044 } 3045 } else { 3046 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3047 } 3048 break; 3049 } 3050 #endif 3051 // generate random number first, if we need to show passkey 3052 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3053 sm_conn->sm_engine_state = SM_PH2_GET_RANDOM_TK; 3054 break; 3055 } 3056 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3057 sm_trigger_user_response(sm_conn); 3058 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3059 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3060 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3061 } 3062 break; 3063 3064 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3065 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3066 sm_pdu_received_in_wrong_state(sm_conn); 3067 break; 3068 } 3069 3070 // store s_confirm 3071 reverse_128(&packet[1], setup->sm_peer_confirm); 3072 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3073 break; 3074 3075 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3076 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3077 sm_pdu_received_in_wrong_state(sm_conn); 3078 break;; 3079 } 3080 3081 // received random value 3082 reverse_128(&packet[1], setup->sm_peer_random); 3083 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3084 break; 3085 3086 // Responder 3087 case SM_RESPONDER_IDLE: 3088 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3089 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3090 if (packet[0] != SM_CODE_PAIRING_REQUEST){ 3091 sm_pdu_received_in_wrong_state(sm_conn); 3092 break;; 3093 } 3094 3095 // store pairing request 3096 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3097 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3098 break; 3099 3100 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3101 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3102 if (packet[0] != SM_CODE_PAIRING_PUBLIC_KEY){ 3103 sm_pdu_received_in_wrong_state(sm_conn); 3104 break; 3105 } 3106 3107 // store public key for DH Key calculation 3108 reverse_256(&packet[01], setup->sm_peer_qx); 3109 reverse_256(&packet[33], setup->sm_peer_qy); 3110 3111 #ifdef USE_MBEDTLS_FOR_ECDH 3112 // validate public key 3113 mbedtls_ecp_point Q; 3114 mbedtls_ecp_point_init( &Q ); 3115 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 3116 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 3117 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 3118 err = mbedtls_ecp_check_pubkey(&mbedtls_ec_group, &Q); 3119 mbedtls_ecp_point_free( & Q); 3120 if (err){ 3121 log_error("sm: peer public key invalid %x", err); 3122 // uses "unspecified reason", there is no "public key invalid" error code 3123 sm_pdu_received_in_wrong_state(sm_conn); 3124 break; 3125 } 3126 3127 #endif 3128 if (sm_conn->sm_role){ 3129 // responder 3130 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3131 } else { 3132 // initiator 3133 // stk generation method 3134 // passkey entry: notify app to show passkey or to request passkey 3135 switch (setup->sm_stk_generation_method){ 3136 case JUST_WORKS: 3137 case NK_BOTH_INPUT: 3138 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3139 break; 3140 case PK_RESP_INPUT: 3141 sm_sc_start_calculating_local_confirm(sm_conn); 3142 break; 3143 case PK_INIT_INPUT: 3144 case OK_BOTH_INPUT: 3145 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3146 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3147 break; 3148 } 3149 sm_sc_start_calculating_local_confirm(sm_conn); 3150 break; 3151 case OOB: 3152 // TODO: implement SC OOB 3153 break; 3154 } 3155 } 3156 break; 3157 3158 case SM_SC_W4_CONFIRMATION: 3159 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3160 sm_pdu_received_in_wrong_state(sm_conn); 3161 break; 3162 } 3163 // received confirm value 3164 reverse_128(&packet[1], setup->sm_peer_confirm); 3165 3166 if (sm_conn->sm_role){ 3167 // responder 3168 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3169 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3170 // still waiting for passkey 3171 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3172 break; 3173 } 3174 } 3175 sm_sc_start_calculating_local_confirm(sm_conn); 3176 } else { 3177 // initiator 3178 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3179 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3180 } else { 3181 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3182 } 3183 } 3184 break; 3185 3186 case SM_SC_W4_PAIRING_RANDOM: 3187 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3188 sm_pdu_received_in_wrong_state(sm_conn); 3189 break; 3190 } 3191 3192 // received random value 3193 reverse_128(&packet[1], setup->sm_peer_nonce); 3194 3195 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3196 // only check for JUST WORK/NC in initiator role AND passkey entry 3197 int passkey_entry = sm_passkey_used(setup->sm_stk_generation_method); 3198 if (sm_conn->sm_role || passkey_entry) { 3199 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3200 } 3201 3202 sm_sc_state_after_receiving_random(sm_conn); 3203 break; 3204 3205 case SM_SC_W2_CALCULATE_G2: 3206 case SM_SC_W4_CALCULATE_G2: 3207 case SM_SC_W2_CALCULATE_F5_SALT: 3208 case SM_SC_W4_CALCULATE_F5_SALT: 3209 case SM_SC_W2_CALCULATE_F5_MACKEY: 3210 case SM_SC_W4_CALCULATE_F5_MACKEY: 3211 case SM_SC_W2_CALCULATE_F5_LTK: 3212 case SM_SC_W4_CALCULATE_F5_LTK: 3213 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3214 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3215 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3216 if (packet[0] != SM_CODE_PAIRING_DHKEY_CHECK){ 3217 sm_pdu_received_in_wrong_state(sm_conn); 3218 break; 3219 } 3220 // store DHKey Check 3221 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3222 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3223 3224 // have we been only waiting for dhkey check command? 3225 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3226 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3227 } 3228 break; 3229 #endif 3230 3231 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3232 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3233 sm_pdu_received_in_wrong_state(sm_conn); 3234 break; 3235 } 3236 3237 // received confirm value 3238 reverse_128(&packet[1], setup->sm_peer_confirm); 3239 3240 // notify client to hide shown passkey 3241 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3242 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3243 } 3244 3245 // handle user cancel pairing? 3246 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3247 setup->sm_pairing_failed_reason = SM_REASON_PASSKEYT_ENTRY_FAILED; 3248 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3249 break; 3250 } 3251 3252 // wait for user action? 3253 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3254 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3255 break; 3256 } 3257 3258 // calculate and send local_confirm 3259 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3260 break; 3261 3262 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3263 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3264 sm_pdu_received_in_wrong_state(sm_conn); 3265 break;; 3266 } 3267 3268 // received random value 3269 reverse_128(&packet[1], setup->sm_peer_random); 3270 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3271 break; 3272 3273 case SM_PH3_RECEIVE_KEYS: 3274 switch(packet[0]){ 3275 case SM_CODE_ENCRYPTION_INFORMATION: 3276 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3277 reverse_128(&packet[1], setup->sm_peer_ltk); 3278 break; 3279 3280 case SM_CODE_MASTER_IDENTIFICATION: 3281 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3282 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3283 reverse_64(&packet[3], setup->sm_peer_rand); 3284 break; 3285 3286 case SM_CODE_IDENTITY_INFORMATION: 3287 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3288 reverse_128(&packet[1], setup->sm_peer_irk); 3289 break; 3290 3291 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3292 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3293 setup->sm_peer_addr_type = packet[1]; 3294 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3295 break; 3296 3297 case SM_CODE_SIGNING_INFORMATION: 3298 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3299 reverse_128(&packet[1], setup->sm_peer_csrk); 3300 break; 3301 default: 3302 // Unexpected PDU 3303 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3304 break; 3305 } 3306 // done with key distribution? 3307 if (sm_key_distribution_all_received(sm_conn)){ 3308 3309 sm_key_distribution_handle_all_received(sm_conn); 3310 3311 if (sm_conn->sm_role){ 3312 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3313 sm_done_for_handle(sm_conn->sm_handle); 3314 } else { 3315 if (setup->sm_use_secure_connections){ 3316 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3317 } else { 3318 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3319 } 3320 } 3321 } 3322 break; 3323 default: 3324 // Unexpected PDU 3325 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3326 break; 3327 } 3328 3329 // try to send preparared packet 3330 sm_run(); 3331 } 3332 3333 // Security Manager Client API 3334 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data)){ 3335 sm_get_oob_data = get_oob_data_callback; 3336 } 3337 3338 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3339 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3340 } 3341 3342 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3343 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3344 } 3345 3346 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3347 sm_min_encryption_key_size = min_size; 3348 sm_max_encryption_key_size = max_size; 3349 } 3350 3351 void sm_set_authentication_requirements(uint8_t auth_req){ 3352 sm_auth_req = auth_req; 3353 } 3354 3355 void sm_set_io_capabilities(io_capability_t io_capability){ 3356 sm_io_capabilities = io_capability; 3357 } 3358 3359 void sm_set_request_security(int enable){ 3360 sm_slave_request_security = enable; 3361 } 3362 3363 void sm_set_er(sm_key_t er){ 3364 memcpy(sm_persistent_er, er, 16); 3365 } 3366 3367 void sm_set_ir(sm_key_t ir){ 3368 memcpy(sm_persistent_ir, ir, 16); 3369 } 3370 3371 // Testing support only 3372 void sm_test_set_irk(sm_key_t irk){ 3373 memcpy(sm_persistent_irk, irk, 16); 3374 sm_persistent_irk_ready = 1; 3375 } 3376 3377 void sm_test_use_fixed_local_csrk(void){ 3378 test_use_fixed_local_csrk = 1; 3379 } 3380 3381 void sm_init(void){ 3382 // set some (BTstack default) ER and IR 3383 int i; 3384 sm_key_t er; 3385 sm_key_t ir; 3386 for (i=0;i<16;i++){ 3387 er[i] = 0x30 + i; 3388 ir[i] = 0x90 + i; 3389 } 3390 sm_set_er(er); 3391 sm_set_ir(ir); 3392 // defaults 3393 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3394 | SM_STK_GENERATION_METHOD_OOB 3395 | SM_STK_GENERATION_METHOD_PASSKEY 3396 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3397 3398 sm_max_encryption_key_size = 16; 3399 sm_min_encryption_key_size = 7; 3400 3401 sm_cmac_state = CMAC_IDLE; 3402 dkg_state = DKG_W4_WORKING; 3403 rau_state = RAU_W4_WORKING; 3404 sm_aes128_state = SM_AES128_IDLE; 3405 sm_address_resolution_test = -1; // no private address to resolve yet 3406 sm_address_resolution_ah_calculation_active = 0; 3407 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3408 sm_address_resolution_general_queue = NULL; 3409 3410 gap_random_adress_update_period = 15 * 60 * 1000L; 3411 3412 sm_active_connection = 0; 3413 3414 test_use_fixed_local_csrk = 0; 3415 3416 // register for HCI Events from HCI 3417 hci_event_callback_registration.callback = &sm_event_packet_handler; 3418 hci_add_event_handler(&hci_event_callback_registration); 3419 3420 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3421 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3422 3423 #ifdef USE_MBEDTLS_FOR_ECDH 3424 ec_key_generation_state = EC_KEY_GENERATION_IDLE; 3425 mbedtls_ecp_group_init(&mbedtls_ec_group); 3426 mbedtls_ecp_group_load(&mbedtls_ec_group, MBEDTLS_ECP_DP_SECP256R1); 3427 #ifndef HAVE_MALLOC 3428 sm_mbedtls_allocator_init(mbedtls_memory_buffer, sizeof(mbedtls_memory_buffer)); 3429 #endif 3430 3431 #if 0 3432 // test 3433 printf("test dhkey check\n"); 3434 sm_key256_t dhkey; 3435 memcpy(setup->sm_peer_qx, ec_qx, 32); 3436 memcpy(setup->sm_peer_qy, ec_qy, 32); 3437 sm_sc_calculate_dhkey(dhkey); 3438 #endif 3439 #endif 3440 } 3441 3442 void sm_use_fixed_ec_keypair(uint8_t * qx, uint8_t * qy, uint8_t * d){ 3443 memcpy(ec_qx, qx, 32); 3444 memcpy(ec_qy, qy, 32); 3445 memcpy(ec_d, d, 32); 3446 sm_have_ec_keypair = 1; 3447 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3448 } 3449 3450 void sm_test_use_fixed_ec_keypair(void){ 3451 #ifdef USE_MBEDTLS_FOR_ECDH 3452 // use test keypair from spec 3453 mbedtls_mpi x; 3454 mbedtls_mpi_init(&x); 3455 mbedtls_mpi_read_string( &x, 16, "3f49f6d4a3c55f3874c9b3e3d2103f504aff607beb40b7995899b8a6cd3c1abd"); 3456 mbedtls_mpi_write_binary(&x, ec_qx, 16); 3457 mbedtls_mpi_read_string( &x, 16, "20b003d2f297be2c5e2c83a7e9f9a5b9eff49111acf4fddbcc0301480e359de6"); 3458 mbedtls_mpi_write_binary(&x, ec_qy, 16); 3459 mbedtls_mpi_read_string( &x, 16, "dc809c49652aeb6d63329abf5a52155c766345c28fed3024741c8ed01589d28b"); 3460 mbedtls_mpi_write_binary(&x, ec_d, 16); 3461 mbedtls_mpi_free(&x); 3462 #endif 3463 sm_have_ec_keypair = 1; 3464 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3465 } 3466 3467 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3468 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3469 if (!hci_con) return NULL; 3470 return &hci_con->sm_connection; 3471 } 3472 3473 // @returns 0 if not encrypted, 7-16 otherwise 3474 int sm_encryption_key_size(hci_con_handle_t con_handle){ 3475 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3476 if (!sm_conn) return 0; // wrong connection 3477 if (!sm_conn->sm_connection_encrypted) return 0; 3478 return sm_conn->sm_actual_encryption_key_size; 3479 } 3480 3481 int sm_authenticated(hci_con_handle_t con_handle){ 3482 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3483 if (!sm_conn) return 0; // wrong connection 3484 if (!sm_conn->sm_connection_encrypted) return 0; // unencrypted connection cannot be authenticated 3485 return sm_conn->sm_connection_authenticated; 3486 } 3487 3488 authorization_state_t sm_authorization_state(hci_con_handle_t con_handle){ 3489 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3490 if (!sm_conn) return AUTHORIZATION_UNKNOWN; // wrong connection 3491 if (!sm_conn->sm_connection_encrypted) return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized 3492 if (!sm_conn->sm_connection_authenticated) return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized 3493 return sm_conn->sm_connection_authorization_state; 3494 } 3495 3496 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3497 switch (sm_conn->sm_engine_state){ 3498 case SM_GENERAL_IDLE: 3499 case SM_RESPONDER_IDLE: 3500 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3501 sm_run(); 3502 break; 3503 default: 3504 break; 3505 } 3506 } 3507 3508 /** 3509 * @brief Trigger Security Request 3510 */ 3511 void sm_send_security_request(hci_con_handle_t con_handle){ 3512 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3513 if (!sm_conn) return; 3514 sm_send_security_request_for_connection(sm_conn); 3515 } 3516 3517 // request pairing 3518 void sm_request_pairing(hci_con_handle_t con_handle){ 3519 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3520 if (!sm_conn) return; // wrong connection 3521 3522 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3523 if (sm_conn->sm_role){ 3524 sm_send_security_request_for_connection(sm_conn); 3525 } else { 3526 // used as a trigger to start central/master/initiator security procedures 3527 uint16_t ediv; 3528 sm_key_t ltk; 3529 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3530 switch (sm_conn->sm_irk_lookup_state){ 3531 case IRK_LOOKUP_FAILED: 3532 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3533 break; 3534 case IRK_LOOKUP_SUCCEEDED: 3535 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3536 if (!sm_is_null_key(ltk) || ediv){ 3537 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3538 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3539 } else { 3540 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3541 } 3542 break; 3543 default: 3544 sm_conn->sm_bonding_requested = 1; 3545 break; 3546 } 3547 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3548 sm_conn->sm_bonding_requested = 1; 3549 } 3550 } 3551 sm_run(); 3552 } 3553 3554 // called by client app on authorization request 3555 void sm_authorization_decline(hci_con_handle_t con_handle){ 3556 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3557 if (!sm_conn) return; // wrong connection 3558 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3559 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3560 } 3561 3562 void sm_authorization_grant(hci_con_handle_t con_handle){ 3563 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3564 if (!sm_conn) return; // wrong connection 3565 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3566 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3567 } 3568 3569 // GAP Bonding API 3570 3571 void sm_bonding_decline(hci_con_handle_t con_handle){ 3572 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3573 if (!sm_conn) return; // wrong connection 3574 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3575 3576 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3577 switch (setup->sm_stk_generation_method){ 3578 case PK_RESP_INPUT: 3579 case PK_INIT_INPUT: 3580 case OK_BOTH_INPUT: 3581 sm_pairing_error(sm_conn, SM_GENERAL_SEND_PAIRING_FAILED); 3582 break; 3583 case NK_BOTH_INPUT: 3584 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 3585 break; 3586 case JUST_WORKS: 3587 case OOB: 3588 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 3589 break; 3590 } 3591 } 3592 sm_run(); 3593 } 3594 3595 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3596 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3597 if (!sm_conn) return; // wrong connection 3598 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3599 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3600 if (setup->sm_use_secure_connections){ 3601 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3602 } else { 3603 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3604 } 3605 } 3606 3607 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3608 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3609 sm_sc_prepare_dhkey_check(sm_conn); 3610 } 3611 #endif 3612 3613 sm_run(); 3614 } 3615 3616 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3617 // for now, it's the same 3618 sm_just_works_confirm(con_handle); 3619 } 3620 3621 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3622 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3623 if (!sm_conn) return; // wrong connection 3624 sm_reset_tk(); 3625 big_endian_store_32(setup->sm_tk, 12, passkey); 3626 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3627 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3628 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3629 } 3630 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3631 memcpy(setup->sm_ra, setup->sm_tk, 16); 3632 memcpy(setup->sm_rb, setup->sm_tk, 16); 3633 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3634 sm_sc_start_calculating_local_confirm(sm_conn); 3635 } 3636 #endif 3637 sm_run(); 3638 } 3639 3640 /** 3641 * @brief Identify device in LE Device DB 3642 * @param handle 3643 * @returns index from le_device_db or -1 if not found/identified 3644 */ 3645 int sm_le_device_index(hci_con_handle_t con_handle ){ 3646 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3647 if (!sm_conn) return -1; 3648 return sm_conn->sm_le_db_index; 3649 } 3650 3651 // GAP LE API 3652 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 3653 gap_random_address_update_stop(); 3654 gap_random_adress_type = random_address_type; 3655 if (random_address_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3656 gap_random_address_update_start(); 3657 gap_random_address_trigger(); 3658 } 3659 3660 gap_random_address_type_t gap_random_address_get_mode(void){ 3661 return gap_random_adress_type; 3662 } 3663 3664 void gap_random_address_set_update_period(int period_ms){ 3665 gap_random_adress_update_period = period_ms; 3666 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3667 gap_random_address_update_stop(); 3668 gap_random_address_update_start(); 3669 } 3670 3671 void gap_random_address_set(bd_addr_t addr){ 3672 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_OFF); 3673 memcpy(sm_random_address, addr, 6); 3674 rau_state = RAU_SET_ADDRESS; 3675 sm_run(); 3676 } 3677 3678 /* 3679 * @brief Set Advertisement Paramters 3680 * @param adv_int_min 3681 * @param adv_int_max 3682 * @param adv_type 3683 * @param direct_address_type 3684 * @param direct_address 3685 * @param channel_map 3686 * @param filter_policy 3687 * 3688 * @note own_address_type is used from gap_random_address_set_mode 3689 */ 3690 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 3691 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 3692 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, gap_random_adress_type, 3693 direct_address_typ, direct_address, channel_map, filter_policy); 3694 } 3695 3696