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 #ifdef ENABLE_LE_SECURE_CONNECTIONS 160 static uint8_t sm_have_ec_keypair; 161 #endif 162 163 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 164 static sm_key_t sm_persistent_er; 165 static sm_key_t sm_persistent_ir; 166 167 // derived from sm_persistent_ir 168 static sm_key_t sm_persistent_dhk; 169 static sm_key_t sm_persistent_irk; 170 static uint8_t sm_persistent_irk_ready = 0; // used for testing 171 static derived_key_generation_t dkg_state; 172 173 // derived from sm_persistent_er 174 // .. 175 176 // random address update 177 static random_address_update_t rau_state; 178 static bd_addr_t sm_random_address; 179 180 // CMAC Calculation: General 181 static cmac_state_t sm_cmac_state; 182 static uint16_t sm_cmac_message_len; 183 static sm_key_t sm_cmac_k; 184 static sm_key_t sm_cmac_x; 185 static sm_key_t sm_cmac_m_last; 186 static uint8_t sm_cmac_block_current; 187 static uint8_t sm_cmac_block_count; 188 static uint8_t (*sm_cmac_get_byte)(uint16_t offset); 189 static void (*sm_cmac_done_handler)(uint8_t * hash); 190 191 // CMAC for ATT Signed Writes 192 static uint8_t sm_cmac_header[3]; 193 static const uint8_t * sm_cmac_message; 194 static uint8_t sm_cmac_sign_counter[4]; 195 196 // CMAC for Secure Connection functions 197 #ifdef ENABLE_LE_SECURE_CONNECTIONS 198 static sm_connection_t * sm_cmac_connection; 199 static uint8_t sm_cmac_sc_buffer[80]; 200 #endif 201 202 // resolvable private address lookup / CSRK calculation 203 static int sm_address_resolution_test; 204 static int sm_address_resolution_ah_calculation_active; 205 static uint8_t sm_address_resolution_addr_type; 206 static bd_addr_t sm_address_resolution_address; 207 static void * sm_address_resolution_context; 208 static address_resolution_mode_t sm_address_resolution_mode; 209 static btstack_linked_list_t sm_address_resolution_general_queue; 210 211 // aes128 crypto engine. store current sm_connection_t in sm_aes128_context 212 static sm_aes128_state_t sm_aes128_state; 213 static void * sm_aes128_context; 214 215 // random engine. store context (ususally sm_connection_t) 216 static void * sm_random_context; 217 218 // to receive hci events 219 static btstack_packet_callback_registration_t hci_event_callback_registration; 220 221 /* to dispatch sm event */ 222 static btstack_linked_list_t sm_event_handlers; 223 224 225 // Software ECDH implementation provided by mbedtls 226 #ifdef USE_MBEDTLS_FOR_ECDH 227 // group is always valid 228 static mbedtls_ecp_group mbedtls_ec_group; 229 static ec_key_generation_state_t ec_key_generation_state; 230 static uint8_t ec_qx[32]; 231 static uint8_t ec_qy[32]; 232 static uint8_t ec_d[32]; 233 #ifndef HAVE_MALLOC 234 // 4304 bytes with 73 allocations 235 #define MBEDTLS_ALLOC_BUFFER_SIZE (1300+23*sizeof(void *)) 236 static uint8_t mbedtls_memory_buffer[MBEDTLS_ALLOC_BUFFER_SIZE]; 237 #endif 238 #endif 239 240 // 241 // Volume 3, Part H, Chapter 24 242 // "Security shall be initiated by the Security Manager in the device in the master role. 243 // The device in the slave role shall be the responding device." 244 // -> master := initiator, slave := responder 245 // 246 247 // data needed for security setup 248 typedef struct sm_setup_context { 249 250 btstack_timer_source_t sm_timeout; 251 252 // used in all phases 253 uint8_t sm_pairing_failed_reason; 254 255 // user response, (Phase 1 and/or 2) 256 uint8_t sm_user_response; 257 258 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 259 int sm_key_distribution_send_set; 260 int sm_key_distribution_received_set; 261 262 // Phase 2 (Pairing over SMP) 263 stk_generation_method_t sm_stk_generation_method; 264 sm_key_t sm_tk; 265 uint8_t sm_use_secure_connections; 266 267 sm_key_t sm_c1_t3_value; // c1 calculation 268 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 269 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 270 sm_key_t sm_local_random; 271 sm_key_t sm_local_confirm; 272 sm_key_t sm_peer_random; 273 sm_key_t sm_peer_confirm; 274 uint8_t sm_m_addr_type; // address and type can be removed 275 uint8_t sm_s_addr_type; // '' 276 bd_addr_t sm_m_address; // '' 277 bd_addr_t sm_s_address; // '' 278 sm_key_t sm_ltk; 279 280 uint8_t sm_state_vars; 281 #ifdef ENABLE_LE_SECURE_CONNECTIONS 282 uint8_t sm_peer_qx[32]; // also stores random for EC key generation during init 283 uint8_t sm_peer_qy[32]; // '' 284 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 285 sm_key_t sm_local_nonce; // might be combined with sm_local_random 286 sm_key_t sm_peer_dhkey_check; 287 sm_key_t sm_local_dhkey_check; 288 sm_key_t sm_ra; 289 sm_key_t sm_rb; 290 sm_key_t sm_t; // used for f5 291 sm_key_t sm_mackey; 292 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 293 #endif 294 295 // Phase 3 296 297 // key distribution, we generate 298 uint16_t sm_local_y; 299 uint16_t sm_local_div; 300 uint16_t sm_local_ediv; 301 uint8_t sm_local_rand[8]; 302 sm_key_t sm_local_ltk; 303 sm_key_t sm_local_csrk; 304 sm_key_t sm_local_irk; 305 // sm_local_address/addr_type not needed 306 307 // key distribution, received from peer 308 uint16_t sm_peer_y; 309 uint16_t sm_peer_div; 310 uint16_t sm_peer_ediv; 311 uint8_t sm_peer_rand[8]; 312 sm_key_t sm_peer_ltk; 313 sm_key_t sm_peer_irk; 314 sm_key_t sm_peer_csrk; 315 uint8_t sm_peer_addr_type; 316 bd_addr_t sm_peer_address; 317 318 } sm_setup_context_t; 319 320 // 321 static sm_setup_context_t the_setup; 322 static sm_setup_context_t * setup = &the_setup; 323 324 // active connection - the one for which the_setup is used for 325 static uint16_t sm_active_connection = 0; 326 327 // @returns 1 if oob data is available 328 // stores oob data in provided 16 byte buffer if not null 329 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 330 331 // used to notify applicationss that user interaction is neccessary, see sm_notify_t below 332 static btstack_packet_handler_t sm_client_packet_handler = NULL; 333 334 // horizontal: initiator capabilities 335 // vertial: responder capabilities 336 static const stk_generation_method_t stk_generation_method [5] [5] = { 337 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 338 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 339 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 340 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 341 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 342 }; 343 344 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 345 #ifdef ENABLE_LE_SECURE_CONNECTIONS 346 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 347 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 348 { JUST_WORKS, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 349 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 350 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 351 { PK_RESP_INPUT, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 352 }; 353 #endif 354 355 static void sm_run(void); 356 static void sm_done_for_handle(hci_con_handle_t con_handle); 357 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 358 static inline int sm_calc_actual_encryption_key_size(int other); 359 static int sm_validate_stk_generation_method(void); 360 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data); 361 362 static void log_info_hex16(const char * name, uint16_t value){ 363 log_info("%-6s 0x%04x", name, value); 364 } 365 366 // @returns 1 if all bytes are 0 367 static int sm_is_null(uint8_t * data, int size){ 368 int i; 369 for (i=0; i < size ; i++){ 370 if (data[i]) return 0; 371 } 372 return 1; 373 } 374 375 static int sm_is_null_random(uint8_t random[8]){ 376 return sm_is_null(random, 8); 377 } 378 379 static int sm_is_null_key(uint8_t * key){ 380 return sm_is_null(key, 16); 381 } 382 383 // Key utils 384 static void sm_reset_tk(void){ 385 int i; 386 for (i=0;i<16;i++){ 387 setup->sm_tk[i] = 0; 388 } 389 } 390 391 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 392 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 393 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 394 int i; 395 for (i = max_encryption_size ; i < 16 ; i++){ 396 key[15-i] = 0; 397 } 398 } 399 400 // SMP Timeout implementation 401 402 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 403 // the Security Manager Timer shall be reset and started. 404 // 405 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 406 // 407 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 408 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 409 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 410 // established. 411 412 static void sm_timeout_handler(btstack_timer_source_t * timer){ 413 log_info("SM timeout"); 414 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 415 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 416 sm_done_for_handle(sm_conn->sm_handle); 417 418 // trigger handling of next ready connection 419 sm_run(); 420 } 421 static void sm_timeout_start(sm_connection_t * sm_conn){ 422 btstack_run_loop_remove_timer(&setup->sm_timeout); 423 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 424 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 425 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 426 btstack_run_loop_add_timer(&setup->sm_timeout); 427 } 428 static void sm_timeout_stop(void){ 429 btstack_run_loop_remove_timer(&setup->sm_timeout); 430 } 431 static void sm_timeout_reset(sm_connection_t * sm_conn){ 432 sm_timeout_stop(); 433 sm_timeout_start(sm_conn); 434 } 435 436 // end of sm timeout 437 438 // GAP Random Address updates 439 static gap_random_address_type_t gap_random_adress_type; 440 static btstack_timer_source_t gap_random_address_update_timer; 441 static uint32_t gap_random_adress_update_period; 442 443 static void gap_random_address_trigger(void){ 444 if (rau_state != RAU_IDLE) return; 445 log_info("gap_random_address_trigger"); 446 rau_state = RAU_GET_RANDOM; 447 sm_run(); 448 } 449 450 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 451 log_info("GAP Random Address Update due"); 452 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 453 btstack_run_loop_add_timer(&gap_random_address_update_timer); 454 gap_random_address_trigger(); 455 } 456 457 static void gap_random_address_update_start(void){ 458 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 459 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 460 btstack_run_loop_add_timer(&gap_random_address_update_timer); 461 } 462 463 static void gap_random_address_update_stop(void){ 464 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 465 } 466 467 468 static void sm_random_start(void * context){ 469 sm_random_context = context; 470 hci_send_cmd(&hci_le_rand); 471 } 472 473 // pre: sm_aes128_state != SM_AES128_ACTIVE, hci_can_send_command == 1 474 // context is made availabe to aes128 result handler by this 475 static void sm_aes128_start(sm_key_t key, sm_key_t plaintext, void * context){ 476 sm_aes128_state = SM_AES128_ACTIVE; 477 sm_key_t key_flipped, plaintext_flipped; 478 reverse_128(key, key_flipped); 479 reverse_128(plaintext, plaintext_flipped); 480 sm_aes128_context = context; 481 hci_send_cmd(&hci_le_encrypt, key_flipped, plaintext_flipped); 482 } 483 484 // ah(k,r) helper 485 // r = padding || r 486 // r - 24 bit value 487 static void sm_ah_r_prime(uint8_t r[3], sm_key_t r_prime){ 488 // r'= padding || r 489 memset(r_prime, 0, 16); 490 memcpy(&r_prime[13], r, 3); 491 } 492 493 // d1 helper 494 // d' = padding || r || d 495 // d,r - 16 bit values 496 static void sm_d1_d_prime(uint16_t d, uint16_t r, sm_key_t d1_prime){ 497 // d'= padding || r || d 498 memset(d1_prime, 0, 16); 499 big_endian_store_16(d1_prime, 12, r); 500 big_endian_store_16(d1_prime, 14, d); 501 } 502 503 // dm helper 504 // r’ = padding || r 505 // r - 64 bit value 506 static void sm_dm_r_prime(uint8_t r[8], sm_key_t r_prime){ 507 memset(r_prime, 0, 16); 508 memcpy(&r_prime[8], r, 8); 509 } 510 511 // calculate arguments for first AES128 operation in C1 function 512 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){ 513 514 // p1 = pres || preq || rat’ || iat’ 515 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 516 // cant octet of pres becomes the most significant octet of p1. 517 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 518 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 519 // p1 is 0x05000800000302070710000001010001." 520 521 sm_key_t p1; 522 reverse_56(pres, &p1[0]); 523 reverse_56(preq, &p1[7]); 524 p1[14] = rat; 525 p1[15] = iat; 526 log_info_key("p1", p1); 527 log_info_key("r", r); 528 529 // t1 = r xor p1 530 int i; 531 for (i=0;i<16;i++){ 532 t1[i] = r[i] ^ p1[i]; 533 } 534 log_info_key("t1", t1); 535 } 536 537 // calculate arguments for second AES128 operation in C1 function 538 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, sm_key_t t3){ 539 // p2 = padding || ia || ra 540 // "The least significant octet of ra becomes the least significant octet of p2 and 541 // the most significant octet of padding becomes the most significant octet of p2. 542 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 543 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 544 545 sm_key_t p2; 546 memset(p2, 0, 16); 547 memcpy(&p2[4], ia, 6); 548 memcpy(&p2[10], ra, 6); 549 log_info_key("p2", p2); 550 551 // c1 = e(k, t2_xor_p2) 552 int i; 553 for (i=0;i<16;i++){ 554 t3[i] = t2[i] ^ p2[i]; 555 } 556 log_info_key("t3", t3); 557 } 558 559 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, sm_key_t r_prime){ 560 log_info_key("r1", r1); 561 log_info_key("r2", r2); 562 memcpy(&r_prime[8], &r2[8], 8); 563 memcpy(&r_prime[0], &r1[8], 8); 564 } 565 566 #ifdef ENABLE_LE_SECURE_CONNECTIONS 567 // Software implementations of crypto toolbox for LE Secure Connection 568 // TODO: replace with code to use AES Engine of HCI Controller 569 typedef uint8_t sm_key24_t[3]; 570 typedef uint8_t sm_key56_t[7]; 571 typedef uint8_t sm_key256_t[32]; 572 573 #if 0 574 static void aes128_calc_cyphertext(const uint8_t key[16], const uint8_t plaintext[16], uint8_t cyphertext[16]){ 575 uint32_t rk[RKLENGTH(KEYBITS)]; 576 int nrounds = rijndaelSetupEncrypt(rk, &key[0], KEYBITS); 577 rijndaelEncrypt(rk, nrounds, plaintext, cyphertext); 578 } 579 580 static void calc_subkeys(sm_key_t k0, sm_key_t k1, sm_key_t k2){ 581 memcpy(k1, k0, 16); 582 sm_shift_left_by_one_bit_inplace(16, k1); 583 if (k0[0] & 0x80){ 584 k1[15] ^= 0x87; 585 } 586 memcpy(k2, k1, 16); 587 sm_shift_left_by_one_bit_inplace(16, k2); 588 if (k1[0] & 0x80){ 589 k2[15] ^= 0x87; 590 } 591 } 592 593 static void aes_cmac(sm_key_t aes_cmac, const sm_key_t key, const uint8_t * data, int cmac_message_len){ 594 sm_key_t k0, k1, k2, zero; 595 memset(zero, 0, 16); 596 597 aes128_calc_cyphertext(key, zero, k0); 598 calc_subkeys(k0, k1, k2); 599 600 int cmac_block_count = (cmac_message_len + 15) / 16; 601 602 // step 3: .. 603 if (cmac_block_count==0){ 604 cmac_block_count = 1; 605 } 606 607 // step 4: set m_last 608 sm_key_t cmac_m_last; 609 int sm_cmac_last_block_complete = cmac_message_len != 0 && (cmac_message_len & 0x0f) == 0; 610 int i; 611 if (sm_cmac_last_block_complete){ 612 for (i=0;i<16;i++){ 613 cmac_m_last[i] = data[cmac_message_len - 16 + i] ^ k1[i]; 614 } 615 } else { 616 int valid_octets_in_last_block = cmac_message_len & 0x0f; 617 for (i=0;i<16;i++){ 618 if (i < valid_octets_in_last_block){ 619 cmac_m_last[i] = data[(cmac_message_len & 0xfff0) + i] ^ k2[i]; 620 continue; 621 } 622 if (i == valid_octets_in_last_block){ 623 cmac_m_last[i] = 0x80 ^ k2[i]; 624 continue; 625 } 626 cmac_m_last[i] = k2[i]; 627 } 628 } 629 630 // printf("sm_cmac_start: len %u, block count %u\n", cmac_message_len, cmac_block_count); 631 // LOG_KEY(cmac_m_last); 632 633 // Step 5 634 sm_key_t cmac_x; 635 memset(cmac_x, 0, 16); 636 637 // Step 6 638 sm_key_t sm_cmac_y; 639 for (int block = 0 ; block < cmac_block_count-1 ; block++){ 640 for (i=0;i<16;i++){ 641 sm_cmac_y[i] = cmac_x[i] ^ data[block * 16 + i]; 642 } 643 aes128_calc_cyphertext(key, sm_cmac_y, cmac_x); 644 } 645 for (i=0;i<16;i++){ 646 sm_cmac_y[i] = cmac_x[i] ^ cmac_m_last[i]; 647 } 648 649 // Step 7 650 aes128_calc_cyphertext(key, sm_cmac_y, aes_cmac); 651 } 652 #endif 653 654 #if 0 655 // 656 // Link Key Conversion Function h6 657 // 658 // h6(W, keyID) = AES-CMACW(keyID) 659 // - W is 128 bits 660 // - keyID is 32 bits 661 static void h6(sm_key_t res, const sm_key_t w, const uint32_t key_id){ 662 uint8_t key_id_buffer[4]; 663 big_endian_store_32(key_id_buffer, 0, key_id); 664 aes_cmac(res, w, key_id_buffer, 4); 665 } 666 #endif 667 #endif 668 669 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){ 670 event[0] = type; 671 event[1] = event_size - 2; 672 little_endian_store_16(event, 2, con_handle); 673 event[4] = addr_type; 674 reverse_bd_addr(address, &event[5]); 675 } 676 677 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 678 if (sm_client_packet_handler) { 679 sm_client_packet_handler(HCI_EVENT_PACKET, 0, packet, size); 680 } 681 // dispatch to all event handlers 682 btstack_linked_list_iterator_t it; 683 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 684 while (btstack_linked_list_iterator_has_next(&it)){ 685 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 686 entry->callback(packet_type, 0, packet, size); 687 } 688 } 689 690 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 691 uint8_t event[11]; 692 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 693 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 694 } 695 696 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){ 697 uint8_t event[15]; 698 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 699 little_endian_store_32(event, 11, passkey); 700 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 701 } 702 703 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){ 704 uint8_t event[13]; 705 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 706 little_endian_store_16(event, 11, index); 707 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 708 } 709 710 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){ 711 712 uint8_t event[18]; 713 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 714 event[11] = result; 715 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 716 } 717 718 // decide on stk generation based on 719 // - pairing request 720 // - io capabilities 721 // - OOB data availability 722 static void sm_setup_tk(void){ 723 724 // default: just works 725 setup->sm_stk_generation_method = JUST_WORKS; 726 727 #ifdef ENABLE_LE_SECURE_CONNECTIONS 728 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 729 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 730 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 731 memset(setup->sm_ra, 0, 16); 732 memset(setup->sm_rb, 0, 16); 733 #else 734 setup->sm_use_secure_connections = 0; 735 #endif 736 737 // If both devices have not set the MITM option in the Authentication Requirements 738 // Flags, then the IO capabilities shall be ignored and the Just Works association 739 // model shall be used. 740 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 741 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 742 log_info("SM: MITM not required by both -> JUST WORKS"); 743 return; 744 } 745 746 // TODO: with LE SC, OOB is used to transfer data OOB during pairing, single device with OOB is sufficient 747 748 // If both devices have out of band authentication data, then the Authentication 749 // Requirements Flags shall be ignored when selecting the pairing method and the 750 // Out of Band pairing method shall be used. 751 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) 752 && sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)){ 753 log_info("SM: have OOB data"); 754 log_info_key("OOB", setup->sm_tk); 755 setup->sm_stk_generation_method = OOB; 756 return; 757 } 758 759 // Reset TK as it has been setup in sm_init_setup 760 sm_reset_tk(); 761 762 // Also use just works if unknown io capabilites 763 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)){ 764 return; 765 } 766 767 // Otherwise the IO capabilities of the devices shall be used to determine the 768 // pairing method as defined in Table 2.4. 769 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 770 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 771 772 #ifdef ENABLE_LE_SECURE_CONNECTIONS 773 // table not define by default 774 if (setup->sm_use_secure_connections){ 775 generation_method = stk_generation_method_with_secure_connection; 776 } 777 #endif 778 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)]; 779 780 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 781 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); 782 } 783 784 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 785 int flags = 0; 786 if (key_set & SM_KEYDIST_ENC_KEY){ 787 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 788 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 789 } 790 if (key_set & SM_KEYDIST_ID_KEY){ 791 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 792 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 793 } 794 if (key_set & SM_KEYDIST_SIGN){ 795 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 796 } 797 return flags; 798 } 799 800 static void sm_setup_key_distribution(uint8_t key_set){ 801 setup->sm_key_distribution_received_set = 0; 802 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 803 } 804 805 // CSRK Key Lookup 806 807 808 static int sm_address_resolution_idle(void){ 809 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 810 } 811 812 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){ 813 memcpy(sm_address_resolution_address, addr, 6); 814 sm_address_resolution_addr_type = addr_type; 815 sm_address_resolution_test = 0; 816 sm_address_resolution_mode = mode; 817 sm_address_resolution_context = context; 818 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 819 } 820 821 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 822 // check if already in list 823 btstack_linked_list_iterator_t it; 824 sm_lookup_entry_t * entry; 825 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 826 while(btstack_linked_list_iterator_has_next(&it)){ 827 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 828 if (entry->address_type != address_type) continue; 829 if (memcmp(entry->address, address, 6)) continue; 830 // already in list 831 return BTSTACK_BUSY; 832 } 833 entry = btstack_memory_sm_lookup_entry_get(); 834 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 835 entry->address_type = (bd_addr_type_t) address_type; 836 memcpy(entry->address, address, 6); 837 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 838 sm_run(); 839 return 0; 840 } 841 842 // CMAC Implementation using AES128 engine 843 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 844 int i; 845 int carry = 0; 846 for (i=len-1; i >= 0 ; i--){ 847 int new_carry = data[i] >> 7; 848 data[i] = data[i] << 1 | carry; 849 carry = new_carry; 850 } 851 } 852 853 // 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 854 static inline void sm_next_responding_state(sm_connection_t * sm_conn){ 855 sm_conn->sm_engine_state = (security_manager_state_t) (((int)sm_conn->sm_engine_state) + 1); 856 } 857 static inline void dkg_next_state(void){ 858 dkg_state = (derived_key_generation_t) (((int)dkg_state) + 1); 859 } 860 static inline void rau_next_state(void){ 861 rau_state = (random_address_update_t) (((int)rau_state) + 1); 862 } 863 864 // CMAC calculation using AES Engine 865 866 static inline void sm_cmac_next_state(void){ 867 sm_cmac_state = (cmac_state_t) (((int)sm_cmac_state) + 1); 868 } 869 870 static int sm_cmac_last_block_complete(void){ 871 if (sm_cmac_message_len == 0) return 0; 872 return (sm_cmac_message_len & 0x0f) == 0; 873 } 874 875 static inline uint8_t sm_cmac_message_get_byte(uint16_t offset){ 876 if (offset >= sm_cmac_message_len) { 877 log_error("sm_cmac_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_message_len); 878 return 0; 879 } 880 881 offset = sm_cmac_message_len - 1 - offset; 882 883 // sm_cmac_header[3] | message[] | sm_cmac_sign_counter[4] 884 if (offset < 3){ 885 return sm_cmac_header[offset]; 886 } 887 int actual_message_len_incl_header = sm_cmac_message_len - 4; 888 if (offset < actual_message_len_incl_header){ 889 return sm_cmac_message[offset - 3]; 890 } 891 return sm_cmac_sign_counter[offset - actual_message_len_incl_header]; 892 } 893 894 // generic cmac calculation 895 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])){ 896 // Generalized CMAC 897 memcpy(sm_cmac_k, key, 16); 898 memset(sm_cmac_x, 0, 16); 899 sm_cmac_block_current = 0; 900 sm_cmac_message_len = message_len; 901 sm_cmac_done_handler = done_callback; 902 sm_cmac_get_byte = get_byte_callback; 903 904 // step 2: n := ceil(len/const_Bsize); 905 sm_cmac_block_count = (sm_cmac_message_len + 15) / 16; 906 907 // step 3: .. 908 if (sm_cmac_block_count==0){ 909 sm_cmac_block_count = 1; 910 } 911 log_info("sm_cmac_general_start: len %u, block count %u", sm_cmac_message_len, sm_cmac_block_count); 912 913 // first, we need to compute l for k1, k2, and m_last 914 sm_cmac_state = CMAC_CALC_SUBKEYS; 915 916 // let's go 917 sm_run(); 918 } 919 920 // cmac for ATT Message signing 921 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)){ 922 // ATT Message Signing 923 sm_cmac_header[0] = opcode; 924 little_endian_store_16(sm_cmac_header, 1, con_handle); 925 little_endian_store_32(sm_cmac_sign_counter, 0, sign_counter); 926 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 927 sm_cmac_message = message; 928 sm_cmac_general_start(k, total_message_len, &sm_cmac_message_get_byte, done_handler); 929 } 930 931 int sm_cmac_ready(void){ 932 return sm_cmac_state == CMAC_IDLE; 933 } 934 935 static void sm_cmac_handle_aes_engine_ready(void){ 936 switch (sm_cmac_state){ 937 case CMAC_CALC_SUBKEYS: { 938 sm_key_t const_zero; 939 memset(const_zero, 0, 16); 940 sm_cmac_next_state(); 941 sm_aes128_start(sm_cmac_k, const_zero, NULL); 942 break; 943 } 944 case CMAC_CALC_MI: { 945 int j; 946 sm_key_t y; 947 for (j=0;j<16;j++){ 948 y[j] = sm_cmac_x[j] ^ sm_cmac_get_byte(sm_cmac_block_current*16 + j); 949 } 950 sm_cmac_block_current++; 951 sm_cmac_next_state(); 952 sm_aes128_start(sm_cmac_k, y, NULL); 953 break; 954 } 955 case CMAC_CALC_MLAST: { 956 int i; 957 sm_key_t y; 958 for (i=0;i<16;i++){ 959 y[i] = sm_cmac_x[i] ^ sm_cmac_m_last[i]; 960 } 961 log_info_key("Y", y); 962 sm_cmac_block_current++; 963 sm_cmac_next_state(); 964 sm_aes128_start(sm_cmac_k, y, NULL); 965 break; 966 } 967 default: 968 log_info("sm_cmac_handle_aes_engine_ready called in state %u", sm_cmac_state); 969 break; 970 } 971 } 972 973 static void sm_cmac_handle_encryption_result(sm_key_t data){ 974 switch (sm_cmac_state){ 975 case CMAC_W4_SUBKEYS: { 976 sm_key_t k1; 977 memcpy(k1, data, 16); 978 sm_shift_left_by_one_bit_inplace(16, k1); 979 if (data[0] & 0x80){ 980 k1[15] ^= 0x87; 981 } 982 sm_key_t k2; 983 memcpy(k2, k1, 16); 984 sm_shift_left_by_one_bit_inplace(16, k2); 985 if (k1[0] & 0x80){ 986 k2[15] ^= 0x87; 987 } 988 989 log_info_key("k", sm_cmac_k); 990 log_info_key("k1", k1); 991 log_info_key("k2", k2); 992 993 // step 4: set m_last 994 int i; 995 if (sm_cmac_last_block_complete()){ 996 for (i=0;i<16;i++){ 997 sm_cmac_m_last[i] = sm_cmac_get_byte(sm_cmac_message_len - 16 + i) ^ k1[i]; 998 } 999 } else { 1000 int valid_octets_in_last_block = sm_cmac_message_len & 0x0f; 1001 for (i=0;i<16;i++){ 1002 if (i < valid_octets_in_last_block){ 1003 sm_cmac_m_last[i] = sm_cmac_get_byte((sm_cmac_message_len & 0xfff0) + i) ^ k2[i]; 1004 continue; 1005 } 1006 if (i == valid_octets_in_last_block){ 1007 sm_cmac_m_last[i] = 0x80 ^ k2[i]; 1008 continue; 1009 } 1010 sm_cmac_m_last[i] = k2[i]; 1011 } 1012 } 1013 1014 // next 1015 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1016 break; 1017 } 1018 case CMAC_W4_MI: 1019 memcpy(sm_cmac_x, data, 16); 1020 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1021 break; 1022 case CMAC_W4_MLAST: 1023 // done 1024 log_info("Setting CMAC Engine to IDLE"); 1025 sm_cmac_state = CMAC_IDLE; 1026 log_info_key("CMAC", data); 1027 sm_cmac_done_handler(data); 1028 break; 1029 default: 1030 log_info("sm_cmac_handle_encryption_result called in state %u", sm_cmac_state); 1031 break; 1032 } 1033 } 1034 1035 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 1036 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 1037 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 1038 switch (setup->sm_stk_generation_method){ 1039 case PK_RESP_INPUT: 1040 if (sm_conn->sm_role){ 1041 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1042 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1043 } else { 1044 sm_notify_client_passkey(SM_EVENT_PASSKEY_DISPLAY_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 1045 } 1046 break; 1047 case PK_INIT_INPUT: 1048 if (sm_conn->sm_role){ 1049 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)); 1050 } else { 1051 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1052 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1053 } 1054 break; 1055 case OK_BOTH_INPUT: 1056 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1057 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1058 break; 1059 case NK_BOTH_INPUT: 1060 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1061 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)); 1062 break; 1063 case JUST_WORKS: 1064 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1065 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1066 break; 1067 case OOB: 1068 // client already provided OOB data, let's skip notification. 1069 break; 1070 } 1071 } 1072 1073 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 1074 int recv_flags; 1075 if (sm_conn->sm_role){ 1076 // slave / responder 1077 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 1078 } else { 1079 // master / initiator 1080 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 1081 } 1082 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1083 return recv_flags == setup->sm_key_distribution_received_set; 1084 } 1085 1086 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1087 if (sm_active_connection == con_handle){ 1088 sm_timeout_stop(); 1089 sm_active_connection = 0; 1090 log_info("sm: connection 0x%x released setup context", con_handle); 1091 } 1092 } 1093 1094 static int sm_key_distribution_flags_for_auth_req(void){ 1095 int flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_SIGN; 1096 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1097 // encryption information only if bonding requested 1098 flags |= SM_KEYDIST_ENC_KEY; 1099 } 1100 return flags; 1101 } 1102 1103 static void sm_init_setup(sm_connection_t * sm_conn){ 1104 1105 // fill in sm setup 1106 setup->sm_state_vars = 0; 1107 sm_reset_tk(); 1108 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1109 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1110 1111 // query client for OOB data 1112 int have_oob_data = 0; 1113 if (sm_get_oob_data) { 1114 have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1115 } 1116 1117 sm_pairing_packet_t * local_packet; 1118 if (sm_conn->sm_role){ 1119 // slave 1120 local_packet = &setup->sm_s_pres; 1121 gap_advertisements_get_address(&setup->sm_s_addr_type, setup->sm_s_address); 1122 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1123 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1124 } else { 1125 // master 1126 local_packet = &setup->sm_m_preq; 1127 gap_advertisements_get_address(&setup->sm_m_addr_type, setup->sm_m_address); 1128 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1129 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1130 1131 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1132 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1133 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1134 } 1135 1136 uint8_t auth_req = sm_auth_req; 1137 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1138 sm_pairing_packet_set_oob_data_flag(*local_packet, have_oob_data); 1139 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1140 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1141 } 1142 1143 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1144 1145 sm_pairing_packet_t * remote_packet; 1146 int remote_key_request; 1147 if (sm_conn->sm_role){ 1148 // slave / responder 1149 remote_packet = &setup->sm_m_preq; 1150 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1151 } else { 1152 // master / initiator 1153 remote_packet = &setup->sm_s_pres; 1154 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1155 } 1156 1157 // check key size 1158 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1159 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1160 1161 // decide on STK generation method 1162 sm_setup_tk(); 1163 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1164 1165 // check if STK generation method is acceptable by client 1166 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1167 1168 // identical to responder 1169 sm_setup_key_distribution(remote_key_request); 1170 1171 // JUST WORKS doens't provide authentication 1172 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1173 1174 return 0; 1175 } 1176 1177 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1178 1179 // cache and reset context 1180 int matched_device_id = sm_address_resolution_test; 1181 address_resolution_mode_t mode = sm_address_resolution_mode; 1182 void * context = sm_address_resolution_context; 1183 1184 // reset context 1185 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1186 sm_address_resolution_context = NULL; 1187 sm_address_resolution_test = -1; 1188 hci_con_handle_t con_handle = 0; 1189 1190 sm_connection_t * sm_connection; 1191 uint16_t ediv; 1192 switch (mode){ 1193 case ADDRESS_RESOLUTION_GENERAL: 1194 break; 1195 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1196 sm_connection = (sm_connection_t *) context; 1197 con_handle = sm_connection->sm_handle; 1198 switch (event){ 1199 case ADDRESS_RESOLUTION_SUCEEDED: 1200 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1201 sm_connection->sm_le_db_index = matched_device_id; 1202 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1203 if (sm_connection->sm_role) break; 1204 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1205 sm_connection->sm_security_request_received = 0; 1206 sm_connection->sm_bonding_requested = 0; 1207 le_device_db_encryption_get(sm_connection->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 1208 if (ediv){ 1209 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1210 } else { 1211 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1212 } 1213 break; 1214 case ADDRESS_RESOLUTION_FAILED: 1215 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1216 if (sm_connection->sm_role) break; 1217 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1218 sm_connection->sm_security_request_received = 0; 1219 sm_connection->sm_bonding_requested = 0; 1220 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1221 break; 1222 } 1223 break; 1224 default: 1225 break; 1226 } 1227 1228 switch (event){ 1229 case ADDRESS_RESOLUTION_SUCEEDED: 1230 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1231 break; 1232 case ADDRESS_RESOLUTION_FAILED: 1233 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1234 break; 1235 } 1236 } 1237 1238 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1239 1240 int le_db_index = -1; 1241 1242 // lookup device based on IRK 1243 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1244 int i; 1245 for (i=0; i < le_device_db_count(); i++){ 1246 sm_key_t irk; 1247 bd_addr_t address; 1248 int address_type; 1249 le_device_db_info(i, &address_type, address, irk); 1250 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1251 log_info("sm: device found for IRK, updating"); 1252 le_db_index = i; 1253 break; 1254 } 1255 } 1256 } 1257 1258 // if not found, lookup via public address if possible 1259 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1260 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1261 int i; 1262 for (i=0; i < le_device_db_count(); i++){ 1263 bd_addr_t address; 1264 int address_type; 1265 le_device_db_info(i, &address_type, address, NULL); 1266 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1267 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1268 log_info("sm: device found for public address, updating"); 1269 le_db_index = i; 1270 break; 1271 } 1272 } 1273 } 1274 1275 // if not found, add to db 1276 if (le_db_index < 0) { 1277 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1278 } 1279 1280 if (le_db_index >= 0){ 1281 le_device_db_local_counter_set(le_db_index, 0); 1282 1283 // store local CSRK 1284 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1285 log_info("sm: store local CSRK"); 1286 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1287 le_device_db_local_counter_set(le_db_index, 0); 1288 } 1289 1290 // store remote CSRK 1291 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1292 log_info("sm: store remote CSRK"); 1293 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1294 le_device_db_remote_counter_set(le_db_index, 0); 1295 } 1296 1297 // store encryption information 1298 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION 1299 && setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 1300 log_info("sm: set encryption information (key size %u, authenticatd %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1301 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1302 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1303 } 1304 } 1305 1306 // keep le_db_index 1307 sm_conn->sm_le_db_index = le_db_index; 1308 } 1309 1310 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1311 setup->sm_pairing_failed_reason = reason; 1312 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1313 } 1314 1315 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1316 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1317 } 1318 1319 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1320 1321 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1322 static int sm_passkey_used(stk_generation_method_t method); 1323 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1324 1325 static void sm_log_ec_keypair(void){ 1326 log_info("Elliptic curve: d"); 1327 log_info_hexdump(ec_d,32); 1328 log_info("Elliptic curve: X"); 1329 log_info_hexdump(ec_qx,32); 1330 log_info("Elliptic curve: Y"); 1331 log_info_hexdump(ec_qy,32); 1332 } 1333 1334 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1335 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1336 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1337 } else { 1338 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1339 } 1340 } 1341 1342 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1343 if (sm_conn->sm_role){ 1344 // Responder 1345 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1346 } else { 1347 // Initiator role 1348 switch (setup->sm_stk_generation_method){ 1349 case JUST_WORKS: 1350 sm_sc_prepare_dhkey_check(sm_conn); 1351 break; 1352 1353 case NK_BOTH_INPUT: 1354 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1355 break; 1356 case PK_INIT_INPUT: 1357 case PK_RESP_INPUT: 1358 case OK_BOTH_INPUT: 1359 if (setup->sm_passkey_bit < 20) { 1360 sm_sc_start_calculating_local_confirm(sm_conn); 1361 } else { 1362 sm_sc_prepare_dhkey_check(sm_conn); 1363 } 1364 break; 1365 case OOB: 1366 // TODO: implement SC OOB 1367 break; 1368 } 1369 } 1370 } 1371 1372 static uint8_t sm_sc_cmac_get_byte(uint16_t offset){ 1373 return sm_cmac_sc_buffer[offset]; 1374 } 1375 1376 static void sm_sc_cmac_done(uint8_t * hash){ 1377 log_info("sm_sc_cmac_done: "); 1378 log_info_hexdump(hash, 16); 1379 1380 sm_connection_t * sm_conn = sm_cmac_connection; 1381 sm_cmac_connection = NULL; 1382 1383 switch (sm_conn->sm_engine_state){ 1384 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1385 memcpy(setup->sm_local_confirm, hash, 16); 1386 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1387 break; 1388 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1389 // check 1390 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1391 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1392 break; 1393 } 1394 sm_sc_state_after_receiving_random(sm_conn); 1395 break; 1396 case SM_SC_W4_CALCULATE_G2: { 1397 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1398 big_endian_store_32(setup->sm_tk, 12, vab); 1399 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1400 sm_trigger_user_response(sm_conn); 1401 break; 1402 } 1403 case SM_SC_W4_CALCULATE_F5_SALT: 1404 memcpy(setup->sm_t, hash, 16); 1405 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1406 break; 1407 case SM_SC_W4_CALCULATE_F5_MACKEY: 1408 memcpy(setup->sm_mackey, hash, 16); 1409 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1410 break; 1411 case SM_SC_W4_CALCULATE_F5_LTK: 1412 memcpy(setup->sm_ltk, hash, 16); 1413 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1414 break; 1415 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1416 memcpy(setup->sm_local_dhkey_check, hash, 16); 1417 if (sm_conn->sm_role){ 1418 // responder 1419 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1420 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1421 } else { 1422 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1423 } 1424 } else { 1425 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1426 } 1427 break; 1428 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1429 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1430 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1431 break; 1432 } 1433 if (sm_conn->sm_role){ 1434 // responder 1435 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1436 } else { 1437 // initiator 1438 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1439 } 1440 break; 1441 default: 1442 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1443 break; 1444 } 1445 sm_run(); 1446 } 1447 1448 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){ 1449 const uint16_t message_len = 65; 1450 sm_cmac_connection = sm_conn; 1451 memcpy(sm_cmac_sc_buffer, u, 32); 1452 memcpy(sm_cmac_sc_buffer+32, v, 32); 1453 sm_cmac_sc_buffer[64] = z; 1454 log_info("f4 key"); 1455 log_info_hexdump(x, 16); 1456 log_info("f4 message"); 1457 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1458 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1459 } 1460 1461 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1462 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1463 static const uint8_t f5_length[] = { 0x01, 0x00}; 1464 1465 static void sm_sc_calculate_dhkey(sm_key256_t dhkey){ 1466 #ifdef USE_MBEDTLS_FOR_ECDH 1467 // da * Pb 1468 mbedtls_mpi d; 1469 mbedtls_ecp_point Q; 1470 mbedtls_ecp_point DH; 1471 mbedtls_mpi_init(&d); 1472 mbedtls_ecp_point_init(&Q); 1473 mbedtls_ecp_point_init(&DH); 1474 mbedtls_mpi_read_binary(&d, ec_d, 32); 1475 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 1476 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 1477 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 1478 mbedtls_ecp_mul(&mbedtls_ec_group, &DH, &d, &Q, NULL, NULL); 1479 mbedtls_mpi_write_binary(&DH.X, dhkey, 32); 1480 mbedtls_mpi_free(&d); 1481 mbedtls_ecp_point_free(&Q); 1482 mbedtls_ecp_point_free(&DH); 1483 #endif 1484 log_info("dhkey"); 1485 log_info_hexdump(dhkey, 32); 1486 } 1487 1488 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1489 // calculate DHKEY 1490 sm_key256_t dhkey; 1491 sm_sc_calculate_dhkey(dhkey); 1492 1493 // calculate salt for f5 1494 const uint16_t message_len = 32; 1495 sm_cmac_connection = sm_conn; 1496 memcpy(sm_cmac_sc_buffer, dhkey, message_len); 1497 sm_cmac_general_start(f5_salt, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1498 } 1499 1500 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){ 1501 const uint16_t message_len = 53; 1502 sm_cmac_connection = sm_conn; 1503 1504 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1505 sm_cmac_sc_buffer[0] = 0; 1506 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1507 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1508 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1509 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1510 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1511 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1512 log_info("f5 key"); 1513 log_info_hexdump(t, 16); 1514 log_info("f5 message for MacKey"); 1515 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1516 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1517 } 1518 1519 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1520 sm_key56_t bd_addr_master, bd_addr_slave; 1521 bd_addr_master[0] = setup->sm_m_addr_type; 1522 bd_addr_slave[0] = setup->sm_s_addr_type; 1523 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1524 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1525 if (sm_conn->sm_role){ 1526 // responder 1527 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1528 } else { 1529 // initiator 1530 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1531 } 1532 } 1533 1534 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1535 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1536 const uint16_t message_len = 53; 1537 sm_cmac_connection = sm_conn; 1538 sm_cmac_sc_buffer[0] = 1; 1539 // 1..52 setup before 1540 log_info("f5 key"); 1541 log_info_hexdump(t, 16); 1542 log_info("f5 message for LTK"); 1543 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1544 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1545 } 1546 1547 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1548 f5_ltk(sm_conn, setup->sm_t); 1549 } 1550 1551 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){ 1552 const uint16_t message_len = 65; 1553 sm_cmac_connection = sm_conn; 1554 memcpy(sm_cmac_sc_buffer, n1, 16); 1555 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1556 memcpy(sm_cmac_sc_buffer+32, r, 16); 1557 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1558 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1559 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1560 log_info("f6 key"); 1561 log_info_hexdump(w, 16); 1562 log_info("f6 message"); 1563 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1564 sm_cmac_general_start(w, 65, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1565 } 1566 1567 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1568 // - U is 256 bits 1569 // - V is 256 bits 1570 // - X is 128 bits 1571 // - Y is 128 bits 1572 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){ 1573 const uint16_t message_len = 80; 1574 sm_cmac_connection = sm_conn; 1575 memcpy(sm_cmac_sc_buffer, u, 32); 1576 memcpy(sm_cmac_sc_buffer+32, v, 32); 1577 memcpy(sm_cmac_sc_buffer+64, y, 16); 1578 log_info("g2 key"); 1579 log_info_hexdump(x, 16); 1580 log_info("g2 message"); 1581 log_info_hexdump(sm_cmac_sc_buffer, sizeof(sm_cmac_sc_buffer)); 1582 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1583 } 1584 1585 static void g2_calculate(sm_connection_t * sm_conn) { 1586 // calc Va if numeric comparison 1587 if (sm_conn->sm_role){ 1588 // responder 1589 g2_engine(sm_conn, setup->sm_peer_qx, ec_qx, setup->sm_peer_nonce, setup->sm_local_nonce);; 1590 } else { 1591 // initiator 1592 g2_engine(sm_conn, ec_qx, setup->sm_peer_qx, setup->sm_local_nonce, setup->sm_peer_nonce); 1593 } 1594 } 1595 1596 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1597 uint8_t z = 0; 1598 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1599 // some form of passkey 1600 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1601 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1602 setup->sm_passkey_bit++; 1603 } 1604 f4_engine(sm_conn, ec_qx, setup->sm_peer_qx, setup->sm_local_nonce, z); 1605 } 1606 1607 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1608 uint8_t z = 0; 1609 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1610 // some form of passkey 1611 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1612 // sm_passkey_bit was increased before sending confirm value 1613 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1614 } 1615 f4_engine(sm_conn, setup->sm_peer_qx, ec_qx, setup->sm_peer_nonce, z); 1616 } 1617 1618 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1619 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1620 } 1621 1622 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1623 // calculate DHKCheck 1624 sm_key56_t bd_addr_master, bd_addr_slave; 1625 bd_addr_master[0] = setup->sm_m_addr_type; 1626 bd_addr_slave[0] = setup->sm_s_addr_type; 1627 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1628 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1629 uint8_t iocap_a[3]; 1630 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1631 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1632 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1633 uint8_t iocap_b[3]; 1634 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1635 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1636 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1637 if (sm_conn->sm_role){ 1638 // responder 1639 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); 1640 } else { 1641 // initiator 1642 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); 1643 } 1644 } 1645 1646 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1647 // validate E = f6() 1648 sm_key56_t bd_addr_master, bd_addr_slave; 1649 bd_addr_master[0] = setup->sm_m_addr_type; 1650 bd_addr_slave[0] = setup->sm_s_addr_type; 1651 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1652 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1653 1654 uint8_t iocap_a[3]; 1655 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1656 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1657 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1658 uint8_t iocap_b[3]; 1659 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1660 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1661 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1662 if (sm_conn->sm_role){ 1663 // responder 1664 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); 1665 } else { 1666 // initiator 1667 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); 1668 } 1669 } 1670 #endif 1671 1672 static void sm_load_security_info(sm_connection_t * sm_connection){ 1673 int encryption_key_size; 1674 int authenticated; 1675 int authorized; 1676 1677 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1678 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1679 &encryption_key_size, &authenticated, &authorized); 1680 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1681 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1682 sm_connection->sm_connection_authenticated = authenticated; 1683 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1684 } 1685 1686 static void sm_run(void){ 1687 1688 btstack_linked_list_iterator_t it; 1689 1690 // assert that we can send at least commands 1691 if (!hci_can_send_command_packet_now()) return; 1692 1693 // 1694 // non-connection related behaviour 1695 // 1696 1697 // distributed key generation 1698 switch (dkg_state){ 1699 case DKG_CALC_IRK: 1700 // already busy? 1701 if (sm_aes128_state == SM_AES128_IDLE) { 1702 // IRK = d1(IR, 1, 0) 1703 sm_key_t d1_prime; 1704 sm_d1_d_prime(1, 0, d1_prime); // plaintext 1705 dkg_next_state(); 1706 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1707 return; 1708 } 1709 break; 1710 case DKG_CALC_DHK: 1711 // already busy? 1712 if (sm_aes128_state == SM_AES128_IDLE) { 1713 // DHK = d1(IR, 3, 0) 1714 sm_key_t d1_prime; 1715 sm_d1_d_prime(3, 0, d1_prime); // plaintext 1716 dkg_next_state(); 1717 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1718 return; 1719 } 1720 break; 1721 default: 1722 break; 1723 } 1724 1725 #ifdef USE_MBEDTLS_FOR_ECDH 1726 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 1727 sm_random_start(NULL); 1728 return; 1729 } 1730 #endif 1731 1732 // random address updates 1733 switch (rau_state){ 1734 case RAU_GET_RANDOM: 1735 rau_next_state(); 1736 sm_random_start(NULL); 1737 return; 1738 case RAU_GET_ENC: 1739 // already busy? 1740 if (sm_aes128_state == SM_AES128_IDLE) { 1741 sm_key_t r_prime; 1742 sm_ah_r_prime(sm_random_address, r_prime); 1743 rau_next_state(); 1744 sm_aes128_start(sm_persistent_irk, r_prime, NULL); 1745 return; 1746 } 1747 break; 1748 case RAU_SET_ADDRESS: 1749 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1750 rau_state = RAU_IDLE; 1751 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1752 return; 1753 default: 1754 break; 1755 } 1756 1757 // CMAC 1758 switch (sm_cmac_state){ 1759 case CMAC_CALC_SUBKEYS: 1760 case CMAC_CALC_MI: 1761 case CMAC_CALC_MLAST: 1762 // already busy? 1763 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1764 sm_cmac_handle_aes_engine_ready(); 1765 return; 1766 default: 1767 break; 1768 } 1769 1770 // CSRK Lookup 1771 // -- if csrk lookup ready, find connection that require csrk lookup 1772 if (sm_address_resolution_idle()){ 1773 hci_connections_get_iterator(&it); 1774 while(btstack_linked_list_iterator_has_next(&it)){ 1775 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1776 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1777 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1778 // and start lookup 1779 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); 1780 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1781 break; 1782 } 1783 } 1784 } 1785 1786 // -- if csrk lookup ready, resolved addresses for received addresses 1787 if (sm_address_resolution_idle()) { 1788 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1789 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1790 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1791 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1792 btstack_memory_sm_lookup_entry_free(entry); 1793 } 1794 } 1795 1796 // -- Continue with CSRK device lookup by public or resolvable private address 1797 if (!sm_address_resolution_idle()){ 1798 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_count()); 1799 while (sm_address_resolution_test < le_device_db_count()){ 1800 int addr_type; 1801 bd_addr_t addr; 1802 sm_key_t irk; 1803 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1804 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1805 1806 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1807 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1808 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1809 break; 1810 } 1811 1812 if (sm_address_resolution_addr_type == 0){ 1813 sm_address_resolution_test++; 1814 continue; 1815 } 1816 1817 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1818 1819 log_info("LE Device Lookup: calculate AH"); 1820 log_info_key("IRK", irk); 1821 1822 sm_key_t r_prime; 1823 sm_ah_r_prime(sm_address_resolution_address, r_prime); 1824 sm_address_resolution_ah_calculation_active = 1; 1825 sm_aes128_start(irk, r_prime, sm_address_resolution_context); // keep context 1826 return; 1827 } 1828 1829 if (sm_address_resolution_test >= le_device_db_count()){ 1830 log_info("LE Device Lookup: not found"); 1831 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1832 } 1833 } 1834 1835 1836 // 1837 // active connection handling 1838 // -- use loop to handle next connection if lock on setup context is released 1839 1840 while (1) { 1841 1842 // Find connections that requires setup context and make active if no other is locked 1843 hci_connections_get_iterator(&it); 1844 while(!sm_active_connection && btstack_linked_list_iterator_has_next(&it)){ 1845 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1846 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1847 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 1848 int done = 1; 1849 int err; 1850 switch (sm_connection->sm_engine_state) { 1851 case SM_RESPONDER_SEND_SECURITY_REQUEST: 1852 // send packet if possible, 1853 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 1854 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 1855 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 1856 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1857 } else { 1858 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1859 } 1860 // don't lock sxetup context yet 1861 done = 0; 1862 break; 1863 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 1864 sm_init_setup(sm_connection); 1865 // recover pairing request 1866 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 1867 err = sm_stk_generation_init(sm_connection); 1868 if (err){ 1869 setup->sm_pairing_failed_reason = err; 1870 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1871 break; 1872 } 1873 sm_timeout_start(sm_connection); 1874 // generate random number first, if we need to show passkey 1875 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 1876 sm_connection->sm_engine_state = SM_PH2_GET_RANDOM_TK; 1877 break; 1878 } 1879 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 1880 break; 1881 case SM_INITIATOR_PH0_HAS_LTK: 1882 sm_load_security_info(sm_connection); 1883 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 1884 break; 1885 case SM_RESPONDER_PH0_RECEIVED_LTK: 1886 switch (sm_connection->sm_irk_lookup_state){ 1887 case IRK_LOOKUP_SUCCEEDED:{ 1888 sm_load_security_info(sm_connection); 1889 sm_connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 1890 break; 1891 } 1892 case IRK_LOOKUP_FAILED: 1893 // assume that we don't have a LTK for ediv == 0 and random == null 1894 if (sm_connection->sm_local_ediv == 0 && sm_is_null_random(sm_connection->sm_local_rand)){ 1895 log_info("LTK Request: ediv & random are empty"); 1896 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1897 // TODO: no need to lock context yet -> done = 0; 1898 break; 1899 } 1900 // re-establish previously used LTK using Rand and EDIV 1901 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1902 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1903 // re-establish used key encryption size 1904 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1905 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1906 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1907 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1908 log_info("sm: received ltk request with key size %u, authenticated %u", 1909 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1910 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1911 break; 1912 default: 1913 // just wait until IRK lookup is completed 1914 // don't lock sxetup context yet 1915 done = 0; 1916 break; 1917 } 1918 break; 1919 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 1920 sm_init_setup(sm_connection); 1921 sm_timeout_start(sm_connection); 1922 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 1923 break; 1924 default: 1925 done = 0; 1926 break; 1927 } 1928 if (done){ 1929 sm_active_connection = sm_connection->sm_handle; 1930 log_info("sm: connection 0x%04x locked setup context as %s", sm_active_connection, sm_connection->sm_role ? "responder" : "initiator"); 1931 } 1932 } 1933 1934 // 1935 // active connection handling 1936 // 1937 1938 if (sm_active_connection == 0) return; 1939 1940 // assert that we could send a SM PDU - not needed for all of the following 1941 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 1942 l2cap_request_can_send_fix_channel_now_event(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1943 return; 1944 } 1945 1946 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection); 1947 if (!connection) return; 1948 1949 sm_key_t plaintext; 1950 int key_distribution_flags; 1951 1952 log_info("sm_run: state %u", connection->sm_engine_state); 1953 1954 // responding state 1955 switch (connection->sm_engine_state){ 1956 1957 // general 1958 case SM_GENERAL_SEND_PAIRING_FAILED: { 1959 uint8_t buffer[2]; 1960 buffer[0] = SM_CODE_PAIRING_FAILED; 1961 buffer[1] = setup->sm_pairing_failed_reason; 1962 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 1963 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1964 sm_done_for_handle(connection->sm_handle); 1965 break; 1966 } 1967 1968 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1969 case SM_SC_W2_GET_RANDOM_A: 1970 sm_random_start(connection); 1971 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_A; 1972 break; 1973 case SM_SC_W2_GET_RANDOM_B: 1974 sm_random_start(connection); 1975 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_B; 1976 break; 1977 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 1978 if (!sm_cmac_ready()) break; 1979 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 1980 sm_sc_calculate_local_confirm(connection); 1981 break; 1982 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 1983 if (!sm_cmac_ready()) break; 1984 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 1985 sm_sc_calculate_remote_confirm(connection); 1986 break; 1987 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 1988 if (!sm_cmac_ready()) break; 1989 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 1990 sm_sc_calculate_f6_for_dhkey_check(connection); 1991 break; 1992 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1993 if (!sm_cmac_ready()) break; 1994 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1995 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 1996 break; 1997 case SM_SC_W2_CALCULATE_F5_SALT: 1998 if (!sm_cmac_ready()) break; 1999 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2000 f5_calculate_salt(connection); 2001 break; 2002 case SM_SC_W2_CALCULATE_F5_MACKEY: 2003 if (!sm_cmac_ready()) break; 2004 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2005 f5_calculate_mackey(connection); 2006 break; 2007 case SM_SC_W2_CALCULATE_F5_LTK: 2008 if (!sm_cmac_ready()) break; 2009 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2010 f5_calculate_ltk(connection); 2011 break; 2012 case SM_SC_W2_CALCULATE_G2: 2013 if (!sm_cmac_ready()) break; 2014 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2015 g2_calculate(connection); 2016 break; 2017 2018 #endif 2019 // initiator side 2020 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2021 sm_key_t peer_ltk_flipped; 2022 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2023 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2024 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2025 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2026 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2027 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2028 return; 2029 } 2030 2031 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2032 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2033 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2034 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2035 sm_timeout_reset(connection); 2036 break; 2037 2038 // responder side 2039 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2040 connection->sm_engine_state = SM_RESPONDER_IDLE; 2041 hci_send_cmd(&hci_le_long_term_key_negative_reply, connection->sm_handle); 2042 sm_done_for_handle(connection->sm_handle); 2043 return; 2044 2045 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2046 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2047 uint8_t buffer[65]; 2048 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2049 // 2050 reverse_256(ec_qx, &buffer[1]); 2051 reverse_256(ec_qy, &buffer[33]); 2052 2053 // stk generation method 2054 // passkey entry: notify app to show passkey or to request passkey 2055 switch (setup->sm_stk_generation_method){ 2056 case JUST_WORKS: 2057 case NK_BOTH_INPUT: 2058 if (connection->sm_role){ 2059 // responder 2060 sm_sc_start_calculating_local_confirm(connection); 2061 } else { 2062 // initiator 2063 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2064 } 2065 break; 2066 case PK_INIT_INPUT: 2067 case PK_RESP_INPUT: 2068 case OK_BOTH_INPUT: 2069 // use random TK for display 2070 memcpy(setup->sm_ra, setup->sm_tk, 16); 2071 memcpy(setup->sm_rb, setup->sm_tk, 16); 2072 setup->sm_passkey_bit = 0; 2073 2074 if (connection->sm_role){ 2075 // responder 2076 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2077 } else { 2078 // initiator 2079 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2080 } 2081 sm_trigger_user_response(connection); 2082 break; 2083 case OOB: 2084 // TODO: implement SC OOB 2085 break; 2086 } 2087 2088 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2089 sm_timeout_reset(connection); 2090 break; 2091 } 2092 case SM_SC_SEND_CONFIRMATION: { 2093 uint8_t buffer[17]; 2094 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2095 reverse_128(setup->sm_local_confirm, &buffer[1]); 2096 if (connection->sm_role){ 2097 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2098 } else { 2099 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2100 } 2101 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2102 sm_timeout_reset(connection); 2103 break; 2104 } 2105 case SM_SC_SEND_PAIRING_RANDOM: { 2106 uint8_t buffer[17]; 2107 buffer[0] = SM_CODE_PAIRING_RANDOM; 2108 reverse_128(setup->sm_local_nonce, &buffer[1]); 2109 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT && setup->sm_passkey_bit < 20){ 2110 if (connection->sm_role){ 2111 // responder 2112 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2113 } else { 2114 // initiator 2115 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2116 } 2117 } else { 2118 if (connection->sm_role){ 2119 // responder 2120 if (setup->sm_stk_generation_method == NK_BOTH_INPUT){ 2121 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2122 } else { 2123 sm_sc_prepare_dhkey_check(connection); 2124 } 2125 } else { 2126 // initiator 2127 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2128 } 2129 } 2130 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2131 sm_timeout_reset(connection); 2132 break; 2133 } 2134 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2135 uint8_t buffer[17]; 2136 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2137 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2138 2139 if (connection->sm_role){ 2140 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2141 } else { 2142 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2143 } 2144 2145 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2146 sm_timeout_reset(connection); 2147 break; 2148 } 2149 2150 #endif 2151 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2152 // echo initiator for now 2153 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2154 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2155 2156 if (setup->sm_use_secure_connections){ 2157 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2158 // skip LTK/EDIV for SC 2159 log_info("sm: dropping encryption information flag"); 2160 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2161 } else { 2162 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2163 } 2164 2165 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); 2166 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); 2167 // update key distribution after ENC was dropped 2168 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2169 2170 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2171 sm_timeout_reset(connection); 2172 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2173 if (!setup->sm_use_secure_connections || setup->sm_stk_generation_method == JUST_WORKS){ 2174 sm_trigger_user_response(connection); 2175 } 2176 return; 2177 2178 case SM_PH2_SEND_PAIRING_RANDOM: { 2179 uint8_t buffer[17]; 2180 buffer[0] = SM_CODE_PAIRING_RANDOM; 2181 reverse_128(setup->sm_local_random, &buffer[1]); 2182 if (connection->sm_role){ 2183 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2184 } else { 2185 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2186 } 2187 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2188 sm_timeout_reset(connection); 2189 break; 2190 } 2191 2192 case SM_PH2_GET_RANDOM_TK: 2193 case SM_PH2_C1_GET_RANDOM_A: 2194 case SM_PH2_C1_GET_RANDOM_B: 2195 case SM_PH3_GET_RANDOM: 2196 case SM_PH3_GET_DIV: 2197 sm_next_responding_state(connection); 2198 sm_random_start(connection); 2199 return; 2200 2201 case SM_PH2_C1_GET_ENC_B: 2202 case SM_PH2_C1_GET_ENC_D: 2203 // already busy? 2204 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2205 sm_next_responding_state(connection); 2206 sm_aes128_start(setup->sm_tk, setup->sm_c1_t3_value, connection); 2207 return; 2208 2209 case SM_PH3_LTK_GET_ENC: 2210 case SM_RESPONDER_PH4_LTK_GET_ENC: 2211 // already busy? 2212 if (sm_aes128_state == SM_AES128_IDLE) { 2213 sm_key_t d_prime; 2214 sm_d1_d_prime(setup->sm_local_div, 0, d_prime); 2215 sm_next_responding_state(connection); 2216 sm_aes128_start(sm_persistent_er, d_prime, connection); 2217 return; 2218 } 2219 break; 2220 2221 case SM_PH3_CSRK_GET_ENC: 2222 // already busy? 2223 if (sm_aes128_state == SM_AES128_IDLE) { 2224 sm_key_t d_prime; 2225 sm_d1_d_prime(setup->sm_local_div, 1, d_prime); 2226 sm_next_responding_state(connection); 2227 sm_aes128_start(sm_persistent_er, d_prime, connection); 2228 return; 2229 } 2230 break; 2231 2232 case SM_PH2_C1_GET_ENC_C: 2233 // already busy? 2234 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2235 // calculate m_confirm using aes128 engine - step 1 2236 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); 2237 sm_next_responding_state(connection); 2238 sm_aes128_start(setup->sm_tk, plaintext, connection); 2239 break; 2240 case SM_PH2_C1_GET_ENC_A: 2241 // already busy? 2242 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2243 // calculate confirm using aes128 engine - step 1 2244 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); 2245 sm_next_responding_state(connection); 2246 sm_aes128_start(setup->sm_tk, plaintext, connection); 2247 break; 2248 case SM_PH2_CALC_STK: 2249 // already busy? 2250 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2251 // calculate STK 2252 if (connection->sm_role){ 2253 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, plaintext); 2254 } else { 2255 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, plaintext); 2256 } 2257 sm_next_responding_state(connection); 2258 sm_aes128_start(setup->sm_tk, plaintext, connection); 2259 break; 2260 case SM_PH3_Y_GET_ENC: 2261 // already busy? 2262 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2263 // PH3B2 - calculate Y from - enc 2264 // Y = dm(DHK, Rand) 2265 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2266 sm_next_responding_state(connection); 2267 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2268 return; 2269 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2270 uint8_t buffer[17]; 2271 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2272 reverse_128(setup->sm_local_confirm, &buffer[1]); 2273 if (connection->sm_role){ 2274 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2275 } else { 2276 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2277 } 2278 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2279 sm_timeout_reset(connection); 2280 return; 2281 } 2282 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2283 sm_key_t stk_flipped; 2284 reverse_128(setup->sm_ltk, stk_flipped); 2285 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2286 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2287 return; 2288 } 2289 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2290 sm_key_t stk_flipped; 2291 reverse_128(setup->sm_ltk, stk_flipped); 2292 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2293 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2294 return; 2295 } 2296 case SM_RESPONDER_PH4_SEND_LTK: { 2297 sm_key_t ltk_flipped; 2298 reverse_128(setup->sm_ltk, ltk_flipped); 2299 connection->sm_engine_state = SM_RESPONDER_IDLE; 2300 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2301 return; 2302 } 2303 case SM_RESPONDER_PH4_Y_GET_ENC: 2304 // already busy? 2305 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2306 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2307 // Y = dm(DHK, Rand) 2308 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2309 sm_next_responding_state(connection); 2310 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2311 return; 2312 2313 case SM_PH3_DISTRIBUTE_KEYS: 2314 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2315 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2316 uint8_t buffer[17]; 2317 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2318 reverse_128(setup->sm_ltk, &buffer[1]); 2319 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2320 sm_timeout_reset(connection); 2321 return; 2322 } 2323 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2324 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2325 uint8_t buffer[11]; 2326 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2327 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2328 reverse_64(setup->sm_local_rand, &buffer[3]); 2329 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2330 sm_timeout_reset(connection); 2331 return; 2332 } 2333 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2334 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2335 uint8_t buffer[17]; 2336 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2337 reverse_128(sm_persistent_irk, &buffer[1]); 2338 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2339 sm_timeout_reset(connection); 2340 return; 2341 } 2342 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2343 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2344 bd_addr_t local_address; 2345 uint8_t buffer[8]; 2346 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2347 gap_advertisements_get_address(&buffer[1], local_address); 2348 reverse_bd_addr(local_address, &buffer[2]); 2349 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2350 sm_timeout_reset(connection); 2351 return; 2352 } 2353 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2354 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2355 2356 // hack to reproduce test runs 2357 if (test_use_fixed_local_csrk){ 2358 memset(setup->sm_local_csrk, 0xcc, 16); 2359 } 2360 2361 uint8_t buffer[17]; 2362 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2363 reverse_128(setup->sm_local_csrk, &buffer[1]); 2364 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2365 sm_timeout_reset(connection); 2366 return; 2367 } 2368 2369 // keys are sent 2370 if (connection->sm_role){ 2371 // slave -> receive master keys if any 2372 if (sm_key_distribution_all_received(connection)){ 2373 sm_key_distribution_handle_all_received(connection); 2374 connection->sm_engine_state = SM_RESPONDER_IDLE; 2375 sm_done_for_handle(connection->sm_handle); 2376 } else { 2377 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2378 } 2379 } else { 2380 // master -> all done 2381 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2382 sm_done_for_handle(connection->sm_handle); 2383 } 2384 break; 2385 2386 default: 2387 break; 2388 } 2389 2390 // check again if active connection was released 2391 if (sm_active_connection) break; 2392 } 2393 } 2394 2395 // note: aes engine is ready as we just got the aes result 2396 static void sm_handle_encryption_result(uint8_t * data){ 2397 2398 sm_aes128_state = SM_AES128_IDLE; 2399 2400 if (sm_address_resolution_ah_calculation_active){ 2401 sm_address_resolution_ah_calculation_active = 0; 2402 // compare calulated address against connecting device 2403 uint8_t hash[3]; 2404 reverse_24(data, hash); 2405 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2406 log_info("LE Device Lookup: matched resolvable private address"); 2407 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2408 return; 2409 } 2410 // no match, try next 2411 sm_address_resolution_test++; 2412 return; 2413 } 2414 2415 switch (dkg_state){ 2416 case DKG_W4_IRK: 2417 reverse_128(data, sm_persistent_irk); 2418 log_info_key("irk", sm_persistent_irk); 2419 dkg_next_state(); 2420 return; 2421 case DKG_W4_DHK: 2422 reverse_128(data, sm_persistent_dhk); 2423 log_info_key("dhk", sm_persistent_dhk); 2424 dkg_next_state(); 2425 // SM Init Finished 2426 return; 2427 default: 2428 break; 2429 } 2430 2431 switch (rau_state){ 2432 case RAU_W4_ENC: 2433 reverse_24(data, &sm_random_address[3]); 2434 rau_next_state(); 2435 return; 2436 default: 2437 break; 2438 } 2439 2440 switch (sm_cmac_state){ 2441 case CMAC_W4_SUBKEYS: 2442 case CMAC_W4_MI: 2443 case CMAC_W4_MLAST: 2444 { 2445 sm_key_t t; 2446 reverse_128(data, t); 2447 sm_cmac_handle_encryption_result(t); 2448 } 2449 return; 2450 default: 2451 break; 2452 } 2453 2454 // retrieve sm_connection provided to sm_aes128_start_encryption 2455 sm_connection_t * connection = (sm_connection_t*) sm_aes128_context; 2456 if (!connection) return; 2457 switch (connection->sm_engine_state){ 2458 case SM_PH2_C1_W4_ENC_A: 2459 case SM_PH2_C1_W4_ENC_C: 2460 { 2461 sm_key_t t2; 2462 reverse_128(data, t2); 2463 sm_c1_t3(t2, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2464 } 2465 sm_next_responding_state(connection); 2466 return; 2467 case SM_PH2_C1_W4_ENC_B: 2468 reverse_128(data, setup->sm_local_confirm); 2469 log_info_key("c1!", setup->sm_local_confirm); 2470 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2471 return; 2472 case SM_PH2_C1_W4_ENC_D: 2473 { 2474 sm_key_t peer_confirm_test; 2475 reverse_128(data, peer_confirm_test); 2476 log_info_key("c1!", peer_confirm_test); 2477 if (memcmp(setup->sm_peer_confirm, peer_confirm_test, 16) != 0){ 2478 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2479 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2480 return; 2481 } 2482 if (connection->sm_role){ 2483 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2484 } else { 2485 connection->sm_engine_state = SM_PH2_CALC_STK; 2486 } 2487 } 2488 return; 2489 case SM_PH2_W4_STK: 2490 reverse_128(data, setup->sm_ltk); 2491 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2492 log_info_key("stk", setup->sm_ltk); 2493 if (connection->sm_role){ 2494 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2495 } else { 2496 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2497 } 2498 return; 2499 case SM_PH3_Y_W4_ENC:{ 2500 sm_key_t y128; 2501 reverse_128(data, y128); 2502 setup->sm_local_y = big_endian_read_16(y128, 14); 2503 log_info_hex16("y", setup->sm_local_y); 2504 // PH3B3 - calculate EDIV 2505 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2506 log_info_hex16("ediv", setup->sm_local_ediv); 2507 // PH3B4 - calculate LTK - enc 2508 // LTK = d1(ER, DIV, 0)) 2509 connection->sm_engine_state = SM_PH3_LTK_GET_ENC; 2510 return; 2511 } 2512 case SM_RESPONDER_PH4_Y_W4_ENC:{ 2513 sm_key_t y128; 2514 reverse_128(data, y128); 2515 setup->sm_local_y = big_endian_read_16(y128, 14); 2516 log_info_hex16("y", setup->sm_local_y); 2517 2518 // PH3B3 - calculate DIV 2519 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2520 log_info_hex16("ediv", setup->sm_local_ediv); 2521 // PH3B4 - calculate LTK - enc 2522 // LTK = d1(ER, DIV, 0)) 2523 connection->sm_engine_state = SM_RESPONDER_PH4_LTK_GET_ENC; 2524 return; 2525 } 2526 case SM_PH3_LTK_W4_ENC: 2527 reverse_128(data, setup->sm_ltk); 2528 log_info_key("ltk", setup->sm_ltk); 2529 // calc CSRK next 2530 connection->sm_engine_state = SM_PH3_CSRK_GET_ENC; 2531 return; 2532 case SM_PH3_CSRK_W4_ENC: 2533 reverse_128(data, setup->sm_local_csrk); 2534 log_info_key("csrk", setup->sm_local_csrk); 2535 if (setup->sm_key_distribution_send_set){ 2536 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2537 } else { 2538 // no keys to send, just continue 2539 if (connection->sm_role){ 2540 // slave -> receive master keys 2541 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2542 } else { 2543 // master -> all done 2544 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2545 sm_done_for_handle(connection->sm_handle); 2546 } 2547 } 2548 return; 2549 case SM_RESPONDER_PH4_LTK_W4_ENC: 2550 reverse_128(data, setup->sm_ltk); 2551 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2552 log_info_key("ltk", setup->sm_ltk); 2553 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK; 2554 return; 2555 default: 2556 break; 2557 } 2558 } 2559 2560 #ifdef USE_MBEDTLS_FOR_ECDH 2561 2562 static int sm_generate_f_rng(void * context, unsigned char * buffer, size_t size){ 2563 int offset = setup->sm_passkey_bit; 2564 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, offset); 2565 while (size) { 2566 if (offset < 32){ 2567 *buffer++ = setup->sm_peer_qx[offset++]; 2568 } else { 2569 *buffer++ = setup->sm_peer_qx[offset++ - 32]; 2570 } 2571 size--; 2572 } 2573 setup->sm_passkey_bit = offset; 2574 return 0; 2575 } 2576 #endif 2577 2578 // note: random generator is ready. this doesn NOT imply that aes engine is unused! 2579 static void sm_handle_random_result(uint8_t * data){ 2580 2581 #ifdef USE_MBEDTLS_FOR_ECDH 2582 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 2583 int num_bytes = setup->sm_passkey_bit; 2584 if (num_bytes < 32){ 2585 memcpy(&setup->sm_peer_qx[num_bytes], data, 8); 2586 } else { 2587 memcpy(&setup->sm_peer_qx[num_bytes-32], data, 8); 2588 } 2589 num_bytes += 8; 2590 setup->sm_passkey_bit = num_bytes; 2591 2592 if (num_bytes >= 64){ 2593 // generate EC key 2594 setup->sm_passkey_bit = 0; 2595 mbedtls_mpi d; 2596 mbedtls_ecp_point P; 2597 mbedtls_mpi_init(&d); 2598 mbedtls_ecp_point_init(&P); 2599 int res = mbedtls_ecp_gen_keypair(&mbedtls_ec_group, &d, &P, &sm_generate_f_rng, NULL); 2600 log_info("gen keypair %x", res); 2601 mbedtls_mpi_write_binary(&P.X, ec_qx, 32); 2602 mbedtls_mpi_write_binary(&P.Y, ec_qy, 32); 2603 mbedtls_mpi_write_binary(&d, ec_d, 32); 2604 mbedtls_ecp_point_free(&P); 2605 mbedtls_mpi_free(&d); 2606 ec_key_generation_state = EC_KEY_GENERATION_DONE; 2607 sm_log_ec_keypair(); 2608 2609 #if 0 2610 printf("test dhkey check\n"); 2611 sm_key256_t dhkey; 2612 memcpy(setup->sm_peer_qx, ec_qx, 32); 2613 memcpy(setup->sm_peer_qy, ec_qy, 32); 2614 sm_sc_calculate_dhkey(dhkey); 2615 #endif 2616 2617 } 2618 } 2619 #endif 2620 2621 switch (rau_state){ 2622 case RAU_W4_RANDOM: 2623 // non-resolvable vs. resolvable 2624 switch (gap_random_adress_type){ 2625 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2626 // resolvable: use random as prand and calc address hash 2627 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2628 memcpy(sm_random_address, data, 3); 2629 sm_random_address[0] &= 0x3f; 2630 sm_random_address[0] |= 0x40; 2631 rau_state = RAU_GET_ENC; 2632 break; 2633 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2634 default: 2635 // "The two most significant bits of the address shall be equal to ‘0’"" 2636 memcpy(sm_random_address, data, 6); 2637 sm_random_address[0] &= 0x3f; 2638 rau_state = RAU_SET_ADDRESS; 2639 break; 2640 } 2641 return; 2642 default: 2643 break; 2644 } 2645 2646 // retrieve sm_connection provided to sm_random_start 2647 sm_connection_t * connection = (sm_connection_t *) sm_random_context; 2648 if (!connection) return; 2649 switch (connection->sm_engine_state){ 2650 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2651 case SM_SC_W4_GET_RANDOM_A: 2652 memcpy(&setup->sm_local_nonce[0], data, 8); 2653 connection->sm_engine_state = SM_SC_W2_GET_RANDOM_B; 2654 break; 2655 case SM_SC_W4_GET_RANDOM_B: 2656 memcpy(&setup->sm_local_nonce[8], data, 8); 2657 // initiator & jw/nc -> send pairing random 2658 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2659 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2660 break; 2661 } else { 2662 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2663 } 2664 break; 2665 #endif 2666 2667 case SM_PH2_W4_RANDOM_TK: 2668 { 2669 // map random to 0-999999 without speding much cycles on a modulus operation 2670 uint32_t tk = little_endian_read_32(data,0); 2671 tk = tk & 0xfffff; // 1048575 2672 if (tk >= 999999){ 2673 tk = tk - 999999; 2674 } 2675 sm_reset_tk(); 2676 big_endian_store_32(setup->sm_tk, 12, tk); 2677 if (connection->sm_role){ 2678 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2679 } else { 2680 if (setup->sm_use_secure_connections){ 2681 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 2682 } else { 2683 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2684 sm_trigger_user_response(connection); 2685 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2686 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2687 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 2688 } 2689 } 2690 } 2691 return; 2692 } 2693 case SM_PH2_C1_W4_RANDOM_A: 2694 memcpy(&setup->sm_local_random[0], data, 8); // random endinaness 2695 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_B; 2696 return; 2697 case SM_PH2_C1_W4_RANDOM_B: 2698 memcpy(&setup->sm_local_random[8], data, 8); // random endinaness 2699 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2700 return; 2701 case SM_PH3_W4_RANDOM: 2702 reverse_64(data, setup->sm_local_rand); 2703 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2704 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2705 // no db for authenticated flag hack: store flag in bit 4 of LSB 2706 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2707 connection->sm_engine_state = SM_PH3_GET_DIV; 2708 return; 2709 case SM_PH3_W4_DIV: 2710 // use 16 bit from random value as div 2711 setup->sm_local_div = big_endian_read_16(data, 0); 2712 log_info_hex16("div", setup->sm_local_div); 2713 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2714 return; 2715 default: 2716 break; 2717 } 2718 } 2719 2720 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2721 2722 sm_connection_t * sm_conn; 2723 hci_con_handle_t con_handle; 2724 2725 switch (packet_type) { 2726 2727 case HCI_EVENT_PACKET: 2728 switch (hci_event_packet_get_type(packet)) { 2729 2730 case BTSTACK_EVENT_STATE: 2731 // bt stack activated, get started 2732 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2733 log_info("HCI Working!"); 2734 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 2735 rau_state = RAU_IDLE; 2736 #ifdef USE_MBEDTLS_FOR_ECDH 2737 if (!sm_have_ec_keypair){ 2738 setup->sm_passkey_bit = 0; 2739 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 2740 } 2741 #endif 2742 sm_run(); 2743 } 2744 break; 2745 2746 case HCI_EVENT_LE_META: 2747 switch (packet[2]) { 2748 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2749 2750 log_info("sm: connected"); 2751 2752 if (packet[3]) return; // connection failed 2753 2754 con_handle = little_endian_read_16(packet, 4); 2755 sm_conn = sm_get_connection_for_handle(con_handle); 2756 if (!sm_conn) break; 2757 2758 sm_conn->sm_handle = con_handle; 2759 sm_conn->sm_role = packet[6]; 2760 sm_conn->sm_peer_addr_type = packet[7]; 2761 reverse_bd_addr(&packet[8], 2762 sm_conn->sm_peer_address); 2763 2764 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2765 2766 // reset security properties 2767 sm_conn->sm_connection_encrypted = 0; 2768 sm_conn->sm_connection_authenticated = 0; 2769 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2770 sm_conn->sm_le_db_index = -1; 2771 2772 // prepare CSRK lookup (does not involve setup) 2773 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2774 2775 // just connected -> everything else happens in sm_run() 2776 if (sm_conn->sm_role){ 2777 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2778 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2779 if (sm_slave_request_security) { 2780 // request security if requested by app 2781 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2782 } else { 2783 // otherwise, wait for pairing request 2784 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2785 } 2786 } 2787 break; 2788 } else { 2789 // master 2790 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2791 } 2792 break; 2793 2794 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2795 con_handle = little_endian_read_16(packet, 3); 2796 sm_conn = sm_get_connection_for_handle(con_handle); 2797 if (!sm_conn) break; 2798 2799 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2800 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2801 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2802 break; 2803 } 2804 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 2805 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2806 break; 2807 } 2808 2809 // store rand and ediv 2810 reverse_64(&packet[5], sm_conn->sm_local_rand); 2811 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2812 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK; 2813 break; 2814 2815 default: 2816 break; 2817 } 2818 break; 2819 2820 case HCI_EVENT_ENCRYPTION_CHANGE: 2821 con_handle = little_endian_read_16(packet, 3); 2822 sm_conn = sm_get_connection_for_handle(con_handle); 2823 if (!sm_conn) break; 2824 2825 sm_conn->sm_connection_encrypted = packet[5]; 2826 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 2827 sm_conn->sm_actual_encryption_key_size); 2828 log_info("event handler, state %u", sm_conn->sm_engine_state); 2829 if (!sm_conn->sm_connection_encrypted) break; 2830 // continue if part of initial pairing 2831 switch (sm_conn->sm_engine_state){ 2832 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2833 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2834 sm_done_for_handle(sm_conn->sm_handle); 2835 break; 2836 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2837 if (sm_conn->sm_role){ 2838 // slave 2839 if (setup->sm_use_secure_connections){ 2840 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2841 } else { 2842 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2843 } 2844 } else { 2845 // master 2846 if (sm_key_distribution_all_received(sm_conn)){ 2847 // skip receiving keys as there are none 2848 sm_key_distribution_handle_all_received(sm_conn); 2849 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2850 } else { 2851 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2852 } 2853 } 2854 break; 2855 default: 2856 break; 2857 } 2858 break; 2859 2860 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 2861 con_handle = little_endian_read_16(packet, 3); 2862 sm_conn = sm_get_connection_for_handle(con_handle); 2863 if (!sm_conn) break; 2864 2865 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 2866 log_info("event handler, state %u", sm_conn->sm_engine_state); 2867 // continue if part of initial pairing 2868 switch (sm_conn->sm_engine_state){ 2869 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2870 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2871 sm_done_for_handle(sm_conn->sm_handle); 2872 break; 2873 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2874 if (sm_conn->sm_role){ 2875 // slave 2876 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2877 } else { 2878 // master 2879 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2880 } 2881 break; 2882 default: 2883 break; 2884 } 2885 break; 2886 2887 2888 case HCI_EVENT_DISCONNECTION_COMPLETE: 2889 con_handle = little_endian_read_16(packet, 3); 2890 sm_done_for_handle(con_handle); 2891 sm_conn = sm_get_connection_for_handle(con_handle); 2892 if (!sm_conn) break; 2893 2894 // delete stored bonding on disconnect with authentication failure in ph0 2895 if (sm_conn->sm_role == 0 2896 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 2897 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 2898 le_device_db_remove(sm_conn->sm_le_db_index); 2899 } 2900 2901 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 2902 sm_conn->sm_handle = 0; 2903 break; 2904 2905 case HCI_EVENT_COMMAND_COMPLETE: 2906 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 2907 sm_handle_encryption_result(&packet[6]); 2908 break; 2909 } 2910 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 2911 sm_handle_random_result(&packet[6]); 2912 break; 2913 } 2914 break; 2915 default: 2916 break; 2917 } 2918 break; 2919 default: 2920 break; 2921 } 2922 2923 sm_run(); 2924 } 2925 2926 static inline int sm_calc_actual_encryption_key_size(int other){ 2927 if (other < sm_min_encryption_key_size) return 0; 2928 if (other < sm_max_encryption_key_size) return other; 2929 return sm_max_encryption_key_size; 2930 } 2931 2932 2933 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2934 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 2935 switch (method){ 2936 case JUST_WORKS: 2937 case NK_BOTH_INPUT: 2938 return 1; 2939 default: 2940 return 0; 2941 } 2942 } 2943 // responder 2944 2945 static int sm_passkey_used(stk_generation_method_t method){ 2946 switch (method){ 2947 case PK_RESP_INPUT: 2948 return 1; 2949 default: 2950 return 0; 2951 } 2952 } 2953 #endif 2954 2955 /** 2956 * @return ok 2957 */ 2958 static int sm_validate_stk_generation_method(void){ 2959 // check if STK generation method is acceptable by client 2960 switch (setup->sm_stk_generation_method){ 2961 case JUST_WORKS: 2962 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 2963 case PK_RESP_INPUT: 2964 case PK_INIT_INPUT: 2965 case OK_BOTH_INPUT: 2966 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 2967 case OOB: 2968 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 2969 case NK_BOTH_INPUT: 2970 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 2971 return 1; 2972 default: 2973 return 0; 2974 } 2975 } 2976 2977 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 2978 2979 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 2980 sm_run(); 2981 } 2982 2983 if (packet_type != SM_DATA_PACKET) return; 2984 2985 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 2986 if (!sm_conn) return; 2987 2988 if (packet[0] == SM_CODE_PAIRING_FAILED){ 2989 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2990 return; 2991 } 2992 2993 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, packet[0]); 2994 2995 int err; 2996 2997 switch (sm_conn->sm_engine_state){ 2998 2999 // a sm timeout requries a new physical connection 3000 case SM_GENERAL_TIMEOUT: 3001 return; 3002 3003 // Initiator 3004 case SM_INITIATOR_CONNECTED: 3005 if ((packet[0] != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3006 sm_pdu_received_in_wrong_state(sm_conn); 3007 break; 3008 } 3009 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 3010 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3011 break; 3012 } 3013 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 3014 uint16_t ediv; 3015 sm_key_t ltk; 3016 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3017 if (!sm_is_null_key(ltk) || ediv){ 3018 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3019 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3020 } else { 3021 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3022 } 3023 break; 3024 } 3025 // otherwise, store security request 3026 sm_conn->sm_security_request_received = 1; 3027 break; 3028 3029 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3030 if (packet[0] != SM_CODE_PAIRING_RESPONSE){ 3031 sm_pdu_received_in_wrong_state(sm_conn); 3032 break; 3033 } 3034 // store pairing request 3035 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3036 err = sm_stk_generation_init(sm_conn); 3037 if (err){ 3038 setup->sm_pairing_failed_reason = err; 3039 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3040 break; 3041 } 3042 3043 // generate random number first, if we need to show passkey 3044 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3045 sm_conn->sm_engine_state = SM_PH2_GET_RANDOM_TK; 3046 break; 3047 } 3048 3049 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3050 if (setup->sm_use_secure_connections){ 3051 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3052 if (setup->sm_stk_generation_method == JUST_WORKS){ 3053 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3054 sm_trigger_user_response(sm_conn); 3055 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3056 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3057 } 3058 } else { 3059 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3060 } 3061 break; 3062 } 3063 #endif 3064 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3065 sm_trigger_user_response(sm_conn); 3066 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3067 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3068 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3069 } 3070 break; 3071 3072 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3073 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3074 sm_pdu_received_in_wrong_state(sm_conn); 3075 break; 3076 } 3077 3078 // store s_confirm 3079 reverse_128(&packet[1], setup->sm_peer_confirm); 3080 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3081 break; 3082 3083 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3084 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3085 sm_pdu_received_in_wrong_state(sm_conn); 3086 break;; 3087 } 3088 3089 // received random value 3090 reverse_128(&packet[1], setup->sm_peer_random); 3091 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3092 break; 3093 3094 // Responder 3095 case SM_RESPONDER_IDLE: 3096 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3097 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3098 if (packet[0] != SM_CODE_PAIRING_REQUEST){ 3099 sm_pdu_received_in_wrong_state(sm_conn); 3100 break;; 3101 } 3102 3103 // store pairing request 3104 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3105 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3106 break; 3107 3108 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3109 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3110 if (packet[0] != SM_CODE_PAIRING_PUBLIC_KEY){ 3111 sm_pdu_received_in_wrong_state(sm_conn); 3112 break; 3113 } 3114 3115 // store public key for DH Key calculation 3116 reverse_256(&packet[01], setup->sm_peer_qx); 3117 reverse_256(&packet[33], setup->sm_peer_qy); 3118 3119 #ifdef USE_MBEDTLS_FOR_ECDH 3120 // validate public key 3121 mbedtls_ecp_point Q; 3122 mbedtls_ecp_point_init( &Q ); 3123 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 3124 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 3125 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 3126 err = mbedtls_ecp_check_pubkey(&mbedtls_ec_group, &Q); 3127 mbedtls_ecp_point_free( & Q); 3128 if (err){ 3129 log_error("sm: peer public key invalid %x", err); 3130 // uses "unspecified reason", there is no "public key invalid" error code 3131 sm_pdu_received_in_wrong_state(sm_conn); 3132 break; 3133 } 3134 3135 #endif 3136 if (sm_conn->sm_role){ 3137 // responder 3138 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3139 } else { 3140 // initiator 3141 // stk generation method 3142 // passkey entry: notify app to show passkey or to request passkey 3143 switch (setup->sm_stk_generation_method){ 3144 case JUST_WORKS: 3145 case NK_BOTH_INPUT: 3146 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3147 break; 3148 case PK_RESP_INPUT: 3149 sm_sc_start_calculating_local_confirm(sm_conn); 3150 break; 3151 case PK_INIT_INPUT: 3152 case OK_BOTH_INPUT: 3153 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3154 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3155 break; 3156 } 3157 sm_sc_start_calculating_local_confirm(sm_conn); 3158 break; 3159 case OOB: 3160 // TODO: implement SC OOB 3161 break; 3162 } 3163 } 3164 break; 3165 3166 case SM_SC_W4_CONFIRMATION: 3167 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3168 sm_pdu_received_in_wrong_state(sm_conn); 3169 break; 3170 } 3171 // received confirm value 3172 reverse_128(&packet[1], setup->sm_peer_confirm); 3173 3174 if (sm_conn->sm_role){ 3175 // responder 3176 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3177 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3178 // still waiting for passkey 3179 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3180 break; 3181 } 3182 } 3183 sm_sc_start_calculating_local_confirm(sm_conn); 3184 } else { 3185 // initiator 3186 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3187 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3188 } else { 3189 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3190 } 3191 } 3192 break; 3193 3194 case SM_SC_W4_PAIRING_RANDOM: 3195 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3196 sm_pdu_received_in_wrong_state(sm_conn); 3197 break; 3198 } 3199 3200 // received random value 3201 reverse_128(&packet[1], setup->sm_peer_nonce); 3202 3203 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3204 // only check for JUST WORK/NC in initiator role AND passkey entry 3205 if (sm_conn->sm_role || sm_passkey_used(setup->sm_stk_generation_method)) { 3206 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3207 } 3208 3209 sm_sc_state_after_receiving_random(sm_conn); 3210 break; 3211 3212 case SM_SC_W2_CALCULATE_G2: 3213 case SM_SC_W4_CALCULATE_G2: 3214 case SM_SC_W2_CALCULATE_F5_SALT: 3215 case SM_SC_W4_CALCULATE_F5_SALT: 3216 case SM_SC_W2_CALCULATE_F5_MACKEY: 3217 case SM_SC_W4_CALCULATE_F5_MACKEY: 3218 case SM_SC_W2_CALCULATE_F5_LTK: 3219 case SM_SC_W4_CALCULATE_F5_LTK: 3220 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3221 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3222 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3223 if (packet[0] != SM_CODE_PAIRING_DHKEY_CHECK){ 3224 sm_pdu_received_in_wrong_state(sm_conn); 3225 break; 3226 } 3227 // store DHKey Check 3228 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3229 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3230 3231 // have we been only waiting for dhkey check command? 3232 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3233 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3234 } 3235 break; 3236 #endif 3237 3238 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3239 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3240 sm_pdu_received_in_wrong_state(sm_conn); 3241 break; 3242 } 3243 3244 // received confirm value 3245 reverse_128(&packet[1], setup->sm_peer_confirm); 3246 3247 // notify client to hide shown passkey 3248 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3249 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3250 } 3251 3252 // handle user cancel pairing? 3253 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3254 setup->sm_pairing_failed_reason = SM_REASON_PASSKEYT_ENTRY_FAILED; 3255 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3256 break; 3257 } 3258 3259 // wait for user action? 3260 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3261 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3262 break; 3263 } 3264 3265 // calculate and send local_confirm 3266 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3267 break; 3268 3269 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3270 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3271 sm_pdu_received_in_wrong_state(sm_conn); 3272 break;; 3273 } 3274 3275 // received random value 3276 reverse_128(&packet[1], setup->sm_peer_random); 3277 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3278 break; 3279 3280 case SM_PH3_RECEIVE_KEYS: 3281 switch(packet[0]){ 3282 case SM_CODE_ENCRYPTION_INFORMATION: 3283 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3284 reverse_128(&packet[1], setup->sm_peer_ltk); 3285 break; 3286 3287 case SM_CODE_MASTER_IDENTIFICATION: 3288 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3289 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3290 reverse_64(&packet[3], setup->sm_peer_rand); 3291 break; 3292 3293 case SM_CODE_IDENTITY_INFORMATION: 3294 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3295 reverse_128(&packet[1], setup->sm_peer_irk); 3296 break; 3297 3298 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3299 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3300 setup->sm_peer_addr_type = packet[1]; 3301 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3302 break; 3303 3304 case SM_CODE_SIGNING_INFORMATION: 3305 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3306 reverse_128(&packet[1], setup->sm_peer_csrk); 3307 break; 3308 default: 3309 // Unexpected PDU 3310 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3311 break; 3312 } 3313 // done with key distribution? 3314 if (sm_key_distribution_all_received(sm_conn)){ 3315 3316 sm_key_distribution_handle_all_received(sm_conn); 3317 3318 if (sm_conn->sm_role){ 3319 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3320 sm_done_for_handle(sm_conn->sm_handle); 3321 } else { 3322 if (setup->sm_use_secure_connections){ 3323 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3324 } else { 3325 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3326 } 3327 } 3328 } 3329 break; 3330 default: 3331 // Unexpected PDU 3332 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3333 break; 3334 } 3335 3336 // try to send preparared packet 3337 sm_run(); 3338 } 3339 3340 // Security Manager Client API 3341 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data)){ 3342 sm_get_oob_data = get_oob_data_callback; 3343 } 3344 3345 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3346 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3347 } 3348 3349 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3350 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3351 } 3352 3353 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3354 sm_min_encryption_key_size = min_size; 3355 sm_max_encryption_key_size = max_size; 3356 } 3357 3358 void sm_set_authentication_requirements(uint8_t auth_req){ 3359 sm_auth_req = auth_req; 3360 } 3361 3362 void sm_set_io_capabilities(io_capability_t io_capability){ 3363 sm_io_capabilities = io_capability; 3364 } 3365 3366 void sm_set_request_security(int enable){ 3367 sm_slave_request_security = enable; 3368 } 3369 3370 void sm_set_er(sm_key_t er){ 3371 memcpy(sm_persistent_er, er, 16); 3372 } 3373 3374 void sm_set_ir(sm_key_t ir){ 3375 memcpy(sm_persistent_ir, ir, 16); 3376 } 3377 3378 // Testing support only 3379 void sm_test_set_irk(sm_key_t irk){ 3380 memcpy(sm_persistent_irk, irk, 16); 3381 sm_persistent_irk_ready = 1; 3382 } 3383 3384 void sm_test_use_fixed_local_csrk(void){ 3385 test_use_fixed_local_csrk = 1; 3386 } 3387 3388 void sm_init(void){ 3389 // set some (BTstack default) ER and IR 3390 int i; 3391 sm_key_t er; 3392 sm_key_t ir; 3393 for (i=0;i<16;i++){ 3394 er[i] = 0x30 + i; 3395 ir[i] = 0x90 + i; 3396 } 3397 sm_set_er(er); 3398 sm_set_ir(ir); 3399 // defaults 3400 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3401 | SM_STK_GENERATION_METHOD_OOB 3402 | SM_STK_GENERATION_METHOD_PASSKEY 3403 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3404 3405 sm_max_encryption_key_size = 16; 3406 sm_min_encryption_key_size = 7; 3407 3408 sm_cmac_state = CMAC_IDLE; 3409 dkg_state = DKG_W4_WORKING; 3410 rau_state = RAU_W4_WORKING; 3411 sm_aes128_state = SM_AES128_IDLE; 3412 sm_address_resolution_test = -1; // no private address to resolve yet 3413 sm_address_resolution_ah_calculation_active = 0; 3414 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3415 sm_address_resolution_general_queue = NULL; 3416 3417 gap_random_adress_update_period = 15 * 60 * 1000L; 3418 3419 sm_active_connection = 0; 3420 3421 test_use_fixed_local_csrk = 0; 3422 3423 // register for HCI Events from HCI 3424 hci_event_callback_registration.callback = &sm_event_packet_handler; 3425 hci_add_event_handler(&hci_event_callback_registration); 3426 3427 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3428 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3429 3430 #ifdef USE_MBEDTLS_FOR_ECDH 3431 ec_key_generation_state = EC_KEY_GENERATION_IDLE; 3432 3433 #ifndef HAVE_MALLOC 3434 sm_mbedtls_allocator_init(mbedtls_memory_buffer, sizeof(mbedtls_memory_buffer)); 3435 #endif 3436 mbedtls_ecp_group_init(&mbedtls_ec_group); 3437 mbedtls_ecp_group_load(&mbedtls_ec_group, MBEDTLS_ECP_DP_SECP256R1); 3438 3439 #if 0 3440 // test 3441 sm_test_use_fixed_ec_keypair(); 3442 if (sm_have_ec_keypair){ 3443 printf("test dhkey check\n"); 3444 sm_key256_t dhkey; 3445 memcpy(setup->sm_peer_qx, ec_qx, 32); 3446 memcpy(setup->sm_peer_qy, ec_qy, 32); 3447 sm_sc_calculate_dhkey(dhkey); 3448 } 3449 #endif 3450 #endif 3451 } 3452 3453 void sm_use_fixed_ec_keypair(uint8_t * qx, uint8_t * qy, uint8_t * d){ 3454 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3455 memcpy(ec_qx, qx, 32); 3456 memcpy(ec_qy, qy, 32); 3457 memcpy(ec_d, d, 32); 3458 sm_have_ec_keypair = 1; 3459 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3460 #endif 3461 } 3462 3463 void sm_test_use_fixed_ec_keypair(void){ 3464 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3465 #ifdef USE_MBEDTLS_FOR_ECDH 3466 // use test keypair from spec 3467 mbedtls_mpi x; 3468 mbedtls_mpi_init(&x); 3469 mbedtls_mpi_read_string( &x, 16, "3f49f6d4a3c55f3874c9b3e3d2103f504aff607beb40b7995899b8a6cd3c1abd"); 3470 mbedtls_mpi_write_binary(&x, ec_d, 32); 3471 mbedtls_mpi_read_string( &x, 16, "20b003d2f297be2c5e2c83a7e9f9a5b9eff49111acf4fddbcc0301480e359de6"); 3472 mbedtls_mpi_write_binary(&x, ec_qx, 32); 3473 mbedtls_mpi_read_string( &x, 16, "dc809c49652aeb6d63329abf5a52155c766345c28fed3024741c8ed01589d28b"); 3474 mbedtls_mpi_write_binary(&x, ec_qy, 32); 3475 mbedtls_mpi_free(&x); 3476 #endif 3477 sm_have_ec_keypair = 1; 3478 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3479 #endif 3480 } 3481 3482 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3483 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3484 if (!hci_con) return NULL; 3485 return &hci_con->sm_connection; 3486 } 3487 3488 // @returns 0 if not encrypted, 7-16 otherwise 3489 int sm_encryption_key_size(hci_con_handle_t con_handle){ 3490 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3491 if (!sm_conn) return 0; // wrong connection 3492 if (!sm_conn->sm_connection_encrypted) return 0; 3493 return sm_conn->sm_actual_encryption_key_size; 3494 } 3495 3496 int sm_authenticated(hci_con_handle_t con_handle){ 3497 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3498 if (!sm_conn) return 0; // wrong connection 3499 if (!sm_conn->sm_connection_encrypted) return 0; // unencrypted connection cannot be authenticated 3500 return sm_conn->sm_connection_authenticated; 3501 } 3502 3503 authorization_state_t sm_authorization_state(hci_con_handle_t con_handle){ 3504 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3505 if (!sm_conn) return AUTHORIZATION_UNKNOWN; // wrong connection 3506 if (!sm_conn->sm_connection_encrypted) return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized 3507 if (!sm_conn->sm_connection_authenticated) return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized 3508 return sm_conn->sm_connection_authorization_state; 3509 } 3510 3511 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3512 switch (sm_conn->sm_engine_state){ 3513 case SM_GENERAL_IDLE: 3514 case SM_RESPONDER_IDLE: 3515 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3516 sm_run(); 3517 break; 3518 default: 3519 break; 3520 } 3521 } 3522 3523 /** 3524 * @brief Trigger Security Request 3525 */ 3526 void sm_send_security_request(hci_con_handle_t con_handle){ 3527 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3528 if (!sm_conn) return; 3529 sm_send_security_request_for_connection(sm_conn); 3530 } 3531 3532 // request pairing 3533 void sm_request_pairing(hci_con_handle_t con_handle){ 3534 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3535 if (!sm_conn) return; // wrong connection 3536 3537 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3538 if (sm_conn->sm_role){ 3539 sm_send_security_request_for_connection(sm_conn); 3540 } else { 3541 // used as a trigger to start central/master/initiator security procedures 3542 uint16_t ediv; 3543 sm_key_t ltk; 3544 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3545 switch (sm_conn->sm_irk_lookup_state){ 3546 case IRK_LOOKUP_FAILED: 3547 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3548 break; 3549 case IRK_LOOKUP_SUCCEEDED: 3550 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3551 if (!sm_is_null_key(ltk) || ediv){ 3552 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3553 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3554 } else { 3555 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3556 } 3557 break; 3558 default: 3559 sm_conn->sm_bonding_requested = 1; 3560 break; 3561 } 3562 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3563 sm_conn->sm_bonding_requested = 1; 3564 } 3565 } 3566 sm_run(); 3567 } 3568 3569 // called by client app on authorization request 3570 void sm_authorization_decline(hci_con_handle_t con_handle){ 3571 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3572 if (!sm_conn) return; // wrong connection 3573 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3574 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3575 } 3576 3577 void sm_authorization_grant(hci_con_handle_t con_handle){ 3578 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3579 if (!sm_conn) return; // wrong connection 3580 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3581 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3582 } 3583 3584 // GAP Bonding API 3585 3586 void sm_bonding_decline(hci_con_handle_t con_handle){ 3587 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3588 if (!sm_conn) return; // wrong connection 3589 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3590 3591 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3592 switch (setup->sm_stk_generation_method){ 3593 case PK_RESP_INPUT: 3594 case PK_INIT_INPUT: 3595 case OK_BOTH_INPUT: 3596 sm_pairing_error(sm_conn, SM_GENERAL_SEND_PAIRING_FAILED); 3597 break; 3598 case NK_BOTH_INPUT: 3599 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 3600 break; 3601 case JUST_WORKS: 3602 case OOB: 3603 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 3604 break; 3605 } 3606 } 3607 sm_run(); 3608 } 3609 3610 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3611 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3612 if (!sm_conn) return; // wrong connection 3613 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3614 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3615 if (setup->sm_use_secure_connections){ 3616 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3617 } else { 3618 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3619 } 3620 } 3621 3622 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3623 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3624 sm_sc_prepare_dhkey_check(sm_conn); 3625 } 3626 #endif 3627 3628 sm_run(); 3629 } 3630 3631 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3632 // for now, it's the same 3633 sm_just_works_confirm(con_handle); 3634 } 3635 3636 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3637 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3638 if (!sm_conn) return; // wrong connection 3639 sm_reset_tk(); 3640 big_endian_store_32(setup->sm_tk, 12, passkey); 3641 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3642 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3643 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3644 } 3645 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3646 memcpy(setup->sm_ra, setup->sm_tk, 16); 3647 memcpy(setup->sm_rb, setup->sm_tk, 16); 3648 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3649 sm_sc_start_calculating_local_confirm(sm_conn); 3650 } 3651 #endif 3652 sm_run(); 3653 } 3654 3655 /** 3656 * @brief Identify device in LE Device DB 3657 * @param handle 3658 * @returns index from le_device_db or -1 if not found/identified 3659 */ 3660 int sm_le_device_index(hci_con_handle_t con_handle ){ 3661 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3662 if (!sm_conn) return -1; 3663 return sm_conn->sm_le_db_index; 3664 } 3665 3666 // GAP LE API 3667 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 3668 gap_random_address_update_stop(); 3669 gap_random_adress_type = random_address_type; 3670 if (random_address_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3671 gap_random_address_update_start(); 3672 gap_random_address_trigger(); 3673 } 3674 3675 gap_random_address_type_t gap_random_address_get_mode(void){ 3676 return gap_random_adress_type; 3677 } 3678 3679 void gap_random_address_set_update_period(int period_ms){ 3680 gap_random_adress_update_period = period_ms; 3681 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3682 gap_random_address_update_stop(); 3683 gap_random_address_update_start(); 3684 } 3685 3686 void gap_random_address_set(bd_addr_t addr){ 3687 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_OFF); 3688 memcpy(sm_random_address, addr, 6); 3689 rau_state = RAU_SET_ADDRESS; 3690 sm_run(); 3691 } 3692 3693 /* 3694 * @brief Set Advertisement Paramters 3695 * @param adv_int_min 3696 * @param adv_int_max 3697 * @param adv_type 3698 * @param direct_address_type 3699 * @param direct_address 3700 * @param channel_map 3701 * @param filter_policy 3702 * 3703 * @note own_address_type is used from gap_random_address_set_mode 3704 */ 3705 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 3706 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 3707 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, gap_random_adress_type, 3708 direct_address_typ, direct_address, channel_map, filter_policy); 3709 } 3710 3711