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 uint8_t sm_keypress_notification; 258 259 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 260 int sm_key_distribution_send_set; 261 int sm_key_distribution_received_set; 262 263 // Phase 2 (Pairing over SMP) 264 stk_generation_method_t sm_stk_generation_method; 265 sm_key_t sm_tk; 266 uint8_t sm_use_secure_connections; 267 268 sm_key_t sm_c1_t3_value; // c1 calculation 269 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 270 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 271 sm_key_t sm_local_random; 272 sm_key_t sm_local_confirm; 273 sm_key_t sm_peer_random; 274 sm_key_t sm_peer_confirm; 275 uint8_t sm_m_addr_type; // address and type can be removed 276 uint8_t sm_s_addr_type; // '' 277 bd_addr_t sm_m_address; // '' 278 bd_addr_t sm_s_address; // '' 279 sm_key_t sm_ltk; 280 281 uint8_t sm_state_vars; 282 #ifdef ENABLE_LE_SECURE_CONNECTIONS 283 uint8_t sm_peer_qx[32]; // also stores random for EC key generation during init 284 uint8_t sm_peer_qy[32]; // '' 285 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 286 sm_key_t sm_local_nonce; // might be combined with sm_local_random 287 sm_key_t sm_peer_dhkey_check; 288 sm_key_t sm_local_dhkey_check; 289 sm_key_t sm_ra; 290 sm_key_t sm_rb; 291 sm_key_t sm_t; // used for f5 292 sm_key_t sm_mackey; 293 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 294 #endif 295 296 // Phase 3 297 298 // key distribution, we generate 299 uint16_t sm_local_y; 300 uint16_t sm_local_div; 301 uint16_t sm_local_ediv; 302 uint8_t sm_local_rand[8]; 303 sm_key_t sm_local_ltk; 304 sm_key_t sm_local_csrk; 305 sm_key_t sm_local_irk; 306 // sm_local_address/addr_type not needed 307 308 // key distribution, received from peer 309 uint16_t sm_peer_y; 310 uint16_t sm_peer_div; 311 uint16_t sm_peer_ediv; 312 uint8_t sm_peer_rand[8]; 313 sm_key_t sm_peer_ltk; 314 sm_key_t sm_peer_irk; 315 sm_key_t sm_peer_csrk; 316 uint8_t sm_peer_addr_type; 317 bd_addr_t sm_peer_address; 318 319 } sm_setup_context_t; 320 321 // 322 static sm_setup_context_t the_setup; 323 static sm_setup_context_t * setup = &the_setup; 324 325 // active connection - the one for which the_setup is used for 326 static uint16_t sm_active_connection = 0; 327 328 // @returns 1 if oob data is available 329 // stores oob data in provided 16 byte buffer if not null 330 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 331 332 // horizontal: initiator capabilities 333 // vertial: responder capabilities 334 static const stk_generation_method_t stk_generation_method [5] [5] = { 335 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 336 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 337 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 338 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 339 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 340 }; 341 342 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 343 #ifdef ENABLE_LE_SECURE_CONNECTIONS 344 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 345 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 346 { JUST_WORKS, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 347 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 348 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 349 { PK_RESP_INPUT, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 350 }; 351 #endif 352 353 static void sm_run(void); 354 static void sm_done_for_handle(hci_con_handle_t con_handle); 355 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 356 static inline int sm_calc_actual_encryption_key_size(int other); 357 static int sm_validate_stk_generation_method(void); 358 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data); 359 360 static void log_info_hex16(const char * name, uint16_t value){ 361 log_info("%-6s 0x%04x", name, value); 362 } 363 364 // @returns 1 if all bytes are 0 365 static int sm_is_null(uint8_t * data, int size){ 366 int i; 367 for (i=0; i < size ; i++){ 368 if (data[i]) return 0; 369 } 370 return 1; 371 } 372 373 static int sm_is_null_random(uint8_t random[8]){ 374 return sm_is_null(random, 8); 375 } 376 377 static int sm_is_null_key(uint8_t * key){ 378 return sm_is_null(key, 16); 379 } 380 381 // Key utils 382 static void sm_reset_tk(void){ 383 int i; 384 for (i=0;i<16;i++){ 385 setup->sm_tk[i] = 0; 386 } 387 } 388 389 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 390 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 391 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 392 int i; 393 for (i = max_encryption_size ; i < 16 ; i++){ 394 key[15-i] = 0; 395 } 396 } 397 398 // SMP Timeout implementation 399 400 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 401 // the Security Manager Timer shall be reset and started. 402 // 403 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 404 // 405 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 406 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 407 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 408 // established. 409 410 static void sm_timeout_handler(btstack_timer_source_t * timer){ 411 log_info("SM timeout"); 412 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 413 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 414 sm_done_for_handle(sm_conn->sm_handle); 415 416 // trigger handling of next ready connection 417 sm_run(); 418 } 419 static void sm_timeout_start(sm_connection_t * sm_conn){ 420 btstack_run_loop_remove_timer(&setup->sm_timeout); 421 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 422 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 423 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 424 btstack_run_loop_add_timer(&setup->sm_timeout); 425 } 426 static void sm_timeout_stop(void){ 427 btstack_run_loop_remove_timer(&setup->sm_timeout); 428 } 429 static void sm_timeout_reset(sm_connection_t * sm_conn){ 430 sm_timeout_stop(); 431 sm_timeout_start(sm_conn); 432 } 433 434 // end of sm timeout 435 436 // GAP Random Address updates 437 static gap_random_address_type_t gap_random_adress_type; 438 static btstack_timer_source_t gap_random_address_update_timer; 439 static uint32_t gap_random_adress_update_period; 440 441 static void gap_random_address_trigger(void){ 442 if (rau_state != RAU_IDLE) return; 443 log_info("gap_random_address_trigger"); 444 rau_state = RAU_GET_RANDOM; 445 sm_run(); 446 } 447 448 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 449 log_info("GAP Random Address Update due"); 450 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 451 btstack_run_loop_add_timer(&gap_random_address_update_timer); 452 gap_random_address_trigger(); 453 } 454 455 static void gap_random_address_update_start(void){ 456 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 457 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 458 btstack_run_loop_add_timer(&gap_random_address_update_timer); 459 } 460 461 static void gap_random_address_update_stop(void){ 462 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 463 } 464 465 466 static void sm_random_start(void * context){ 467 sm_random_context = context; 468 hci_send_cmd(&hci_le_rand); 469 } 470 471 // pre: sm_aes128_state != SM_AES128_ACTIVE, hci_can_send_command == 1 472 // context is made availabe to aes128 result handler by this 473 static void sm_aes128_start(sm_key_t key, sm_key_t plaintext, void * context){ 474 sm_aes128_state = SM_AES128_ACTIVE; 475 sm_key_t key_flipped, plaintext_flipped; 476 reverse_128(key, key_flipped); 477 reverse_128(plaintext, plaintext_flipped); 478 sm_aes128_context = context; 479 hci_send_cmd(&hci_le_encrypt, key_flipped, plaintext_flipped); 480 } 481 482 // ah(k,r) helper 483 // r = padding || r 484 // r - 24 bit value 485 static void sm_ah_r_prime(uint8_t r[3], sm_key_t r_prime){ 486 // r'= padding || r 487 memset(r_prime, 0, 16); 488 memcpy(&r_prime[13], r, 3); 489 } 490 491 // d1 helper 492 // d' = padding || r || d 493 // d,r - 16 bit values 494 static void sm_d1_d_prime(uint16_t d, uint16_t r, sm_key_t d1_prime){ 495 // d'= padding || r || d 496 memset(d1_prime, 0, 16); 497 big_endian_store_16(d1_prime, 12, r); 498 big_endian_store_16(d1_prime, 14, d); 499 } 500 501 // dm helper 502 // r’ = padding || r 503 // r - 64 bit value 504 static void sm_dm_r_prime(uint8_t r[8], sm_key_t r_prime){ 505 memset(r_prime, 0, 16); 506 memcpy(&r_prime[8], r, 8); 507 } 508 509 // calculate arguments for first AES128 operation in C1 function 510 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){ 511 512 // p1 = pres || preq || rat’ || iat’ 513 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 514 // cant octet of pres becomes the most significant octet of p1. 515 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 516 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 517 // p1 is 0x05000800000302070710000001010001." 518 519 sm_key_t p1; 520 reverse_56(pres, &p1[0]); 521 reverse_56(preq, &p1[7]); 522 p1[14] = rat; 523 p1[15] = iat; 524 log_info_key("p1", p1); 525 log_info_key("r", r); 526 527 // t1 = r xor p1 528 int i; 529 for (i=0;i<16;i++){ 530 t1[i] = r[i] ^ p1[i]; 531 } 532 log_info_key("t1", t1); 533 } 534 535 // calculate arguments for second AES128 operation in C1 function 536 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, sm_key_t t3){ 537 // p2 = padding || ia || ra 538 // "The least significant octet of ra becomes the least significant octet of p2 and 539 // the most significant octet of padding becomes the most significant octet of p2. 540 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 541 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 542 543 sm_key_t p2; 544 memset(p2, 0, 16); 545 memcpy(&p2[4], ia, 6); 546 memcpy(&p2[10], ra, 6); 547 log_info_key("p2", p2); 548 549 // c1 = e(k, t2_xor_p2) 550 int i; 551 for (i=0;i<16;i++){ 552 t3[i] = t2[i] ^ p2[i]; 553 } 554 log_info_key("t3", t3); 555 } 556 557 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, sm_key_t r_prime){ 558 log_info_key("r1", r1); 559 log_info_key("r2", r2); 560 memcpy(&r_prime[8], &r2[8], 8); 561 memcpy(&r_prime[0], &r1[8], 8); 562 } 563 564 #ifdef ENABLE_LE_SECURE_CONNECTIONS 565 // Software implementations of crypto toolbox for LE Secure Connection 566 // TODO: replace with code to use AES Engine of HCI Controller 567 typedef uint8_t sm_key24_t[3]; 568 typedef uint8_t sm_key56_t[7]; 569 typedef uint8_t sm_key256_t[32]; 570 571 #if 0 572 static void aes128_calc_cyphertext(const uint8_t key[16], const uint8_t plaintext[16], uint8_t cyphertext[16]){ 573 uint32_t rk[RKLENGTH(KEYBITS)]; 574 int nrounds = rijndaelSetupEncrypt(rk, &key[0], KEYBITS); 575 rijndaelEncrypt(rk, nrounds, plaintext, cyphertext); 576 } 577 578 static void calc_subkeys(sm_key_t k0, sm_key_t k1, sm_key_t k2){ 579 memcpy(k1, k0, 16); 580 sm_shift_left_by_one_bit_inplace(16, k1); 581 if (k0[0] & 0x80){ 582 k1[15] ^= 0x87; 583 } 584 memcpy(k2, k1, 16); 585 sm_shift_left_by_one_bit_inplace(16, k2); 586 if (k1[0] & 0x80){ 587 k2[15] ^= 0x87; 588 } 589 } 590 591 static void aes_cmac(sm_key_t aes_cmac, const sm_key_t key, const uint8_t * data, int cmac_message_len){ 592 sm_key_t k0, k1, k2, zero; 593 memset(zero, 0, 16); 594 595 aes128_calc_cyphertext(key, zero, k0); 596 calc_subkeys(k0, k1, k2); 597 598 int cmac_block_count = (cmac_message_len + 15) / 16; 599 600 // step 3: .. 601 if (cmac_block_count==0){ 602 cmac_block_count = 1; 603 } 604 605 // step 4: set m_last 606 sm_key_t cmac_m_last; 607 int sm_cmac_last_block_complete = cmac_message_len != 0 && (cmac_message_len & 0x0f) == 0; 608 int i; 609 if (sm_cmac_last_block_complete){ 610 for (i=0;i<16;i++){ 611 cmac_m_last[i] = data[cmac_message_len - 16 + i] ^ k1[i]; 612 } 613 } else { 614 int valid_octets_in_last_block = cmac_message_len & 0x0f; 615 for (i=0;i<16;i++){ 616 if (i < valid_octets_in_last_block){ 617 cmac_m_last[i] = data[(cmac_message_len & 0xfff0) + i] ^ k2[i]; 618 continue; 619 } 620 if (i == valid_octets_in_last_block){ 621 cmac_m_last[i] = 0x80 ^ k2[i]; 622 continue; 623 } 624 cmac_m_last[i] = k2[i]; 625 } 626 } 627 628 // printf("sm_cmac_start: len %u, block count %u\n", cmac_message_len, cmac_block_count); 629 // LOG_KEY(cmac_m_last); 630 631 // Step 5 632 sm_key_t cmac_x; 633 memset(cmac_x, 0, 16); 634 635 // Step 6 636 sm_key_t sm_cmac_y; 637 for (int block = 0 ; block < cmac_block_count-1 ; block++){ 638 for (i=0;i<16;i++){ 639 sm_cmac_y[i] = cmac_x[i] ^ data[block * 16 + i]; 640 } 641 aes128_calc_cyphertext(key, sm_cmac_y, cmac_x); 642 } 643 for (i=0;i<16;i++){ 644 sm_cmac_y[i] = cmac_x[i] ^ cmac_m_last[i]; 645 } 646 647 // Step 7 648 aes128_calc_cyphertext(key, sm_cmac_y, aes_cmac); 649 } 650 #endif 651 652 #if 0 653 // 654 // Link Key Conversion Function h6 655 // 656 // h6(W, keyID) = AES-CMACW(keyID) 657 // - W is 128 bits 658 // - keyID is 32 bits 659 static void h6(sm_key_t res, const sm_key_t w, const uint32_t key_id){ 660 uint8_t key_id_buffer[4]; 661 big_endian_store_32(key_id_buffer, 0, key_id); 662 aes_cmac(res, w, key_id_buffer, 4); 663 } 664 #endif 665 #endif 666 667 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){ 668 event[0] = type; 669 event[1] = event_size - 2; 670 little_endian_store_16(event, 2, con_handle); 671 event[4] = addr_type; 672 reverse_bd_addr(address, &event[5]); 673 } 674 675 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 676 // dispatch to all event handlers 677 btstack_linked_list_iterator_t it; 678 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 679 while (btstack_linked_list_iterator_has_next(&it)){ 680 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 681 entry->callback(packet_type, 0, packet, size); 682 } 683 } 684 685 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 686 uint8_t event[11]; 687 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 688 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 689 } 690 691 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){ 692 uint8_t event[15]; 693 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 694 little_endian_store_32(event, 11, passkey); 695 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 696 } 697 698 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){ 699 uint8_t event[13]; 700 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 701 little_endian_store_16(event, 11, index); 702 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 703 } 704 705 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){ 706 707 uint8_t event[18]; 708 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 709 event[11] = result; 710 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 711 } 712 713 // decide on stk generation based on 714 // - pairing request 715 // - io capabilities 716 // - OOB data availability 717 static void sm_setup_tk(void){ 718 719 // default: just works 720 setup->sm_stk_generation_method = JUST_WORKS; 721 722 #ifdef ENABLE_LE_SECURE_CONNECTIONS 723 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 724 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 725 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 726 memset(setup->sm_ra, 0, 16); 727 memset(setup->sm_rb, 0, 16); 728 #else 729 setup->sm_use_secure_connections = 0; 730 #endif 731 732 // If both devices have not set the MITM option in the Authentication Requirements 733 // Flags, then the IO capabilities shall be ignored and the Just Works association 734 // model shall be used. 735 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 736 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 737 log_info("SM: MITM not required by both -> JUST WORKS"); 738 return; 739 } 740 741 // TODO: with LE SC, OOB is used to transfer data OOB during pairing, single device with OOB is sufficient 742 743 // If both devices have out of band authentication data, then the Authentication 744 // Requirements Flags shall be ignored when selecting the pairing method and the 745 // Out of Band pairing method shall be used. 746 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) 747 && sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)){ 748 log_info("SM: have OOB data"); 749 log_info_key("OOB", setup->sm_tk); 750 setup->sm_stk_generation_method = OOB; 751 return; 752 } 753 754 // Reset TK as it has been setup in sm_init_setup 755 sm_reset_tk(); 756 757 // Also use just works if unknown io capabilites 758 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)){ 759 return; 760 } 761 762 // Otherwise the IO capabilities of the devices shall be used to determine the 763 // pairing method as defined in Table 2.4. 764 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 765 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 766 767 #ifdef ENABLE_LE_SECURE_CONNECTIONS 768 // table not define by default 769 if (setup->sm_use_secure_connections){ 770 generation_method = stk_generation_method_with_secure_connection; 771 } 772 #endif 773 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)]; 774 775 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 776 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); 777 } 778 779 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 780 int flags = 0; 781 if (key_set & SM_KEYDIST_ENC_KEY){ 782 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 783 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 784 } 785 if (key_set & SM_KEYDIST_ID_KEY){ 786 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 787 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 788 } 789 if (key_set & SM_KEYDIST_SIGN){ 790 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 791 } 792 return flags; 793 } 794 795 static void sm_setup_key_distribution(uint8_t key_set){ 796 setup->sm_key_distribution_received_set = 0; 797 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 798 } 799 800 // CSRK Key Lookup 801 802 803 static int sm_address_resolution_idle(void){ 804 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 805 } 806 807 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){ 808 memcpy(sm_address_resolution_address, addr, 6); 809 sm_address_resolution_addr_type = addr_type; 810 sm_address_resolution_test = 0; 811 sm_address_resolution_mode = mode; 812 sm_address_resolution_context = context; 813 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 814 } 815 816 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 817 // check if already in list 818 btstack_linked_list_iterator_t it; 819 sm_lookup_entry_t * entry; 820 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 821 while(btstack_linked_list_iterator_has_next(&it)){ 822 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 823 if (entry->address_type != address_type) continue; 824 if (memcmp(entry->address, address, 6)) continue; 825 // already in list 826 return BTSTACK_BUSY; 827 } 828 entry = btstack_memory_sm_lookup_entry_get(); 829 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 830 entry->address_type = (bd_addr_type_t) address_type; 831 memcpy(entry->address, address, 6); 832 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 833 sm_run(); 834 return 0; 835 } 836 837 // CMAC Implementation using AES128 engine 838 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 839 int i; 840 int carry = 0; 841 for (i=len-1; i >= 0 ; i--){ 842 int new_carry = data[i] >> 7; 843 data[i] = data[i] << 1 | carry; 844 carry = new_carry; 845 } 846 } 847 848 // 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 849 static inline void sm_next_responding_state(sm_connection_t * sm_conn){ 850 sm_conn->sm_engine_state = (security_manager_state_t) (((int)sm_conn->sm_engine_state) + 1); 851 } 852 static inline void dkg_next_state(void){ 853 dkg_state = (derived_key_generation_t) (((int)dkg_state) + 1); 854 } 855 static inline void rau_next_state(void){ 856 rau_state = (random_address_update_t) (((int)rau_state) + 1); 857 } 858 859 // CMAC calculation using AES Engine 860 861 static inline void sm_cmac_next_state(void){ 862 sm_cmac_state = (cmac_state_t) (((int)sm_cmac_state) + 1); 863 } 864 865 static int sm_cmac_last_block_complete(void){ 866 if (sm_cmac_message_len == 0) return 0; 867 return (sm_cmac_message_len & 0x0f) == 0; 868 } 869 870 static inline uint8_t sm_cmac_message_get_byte(uint16_t offset){ 871 if (offset >= sm_cmac_message_len) { 872 log_error("sm_cmac_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_message_len); 873 return 0; 874 } 875 876 offset = sm_cmac_message_len - 1 - offset; 877 878 // sm_cmac_header[3] | message[] | sm_cmac_sign_counter[4] 879 if (offset < 3){ 880 return sm_cmac_header[offset]; 881 } 882 int actual_message_len_incl_header = sm_cmac_message_len - 4; 883 if (offset < actual_message_len_incl_header){ 884 return sm_cmac_message[offset - 3]; 885 } 886 return sm_cmac_sign_counter[offset - actual_message_len_incl_header]; 887 } 888 889 // generic cmac calculation 890 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])){ 891 // Generalized CMAC 892 memcpy(sm_cmac_k, key, 16); 893 memset(sm_cmac_x, 0, 16); 894 sm_cmac_block_current = 0; 895 sm_cmac_message_len = message_len; 896 sm_cmac_done_handler = done_callback; 897 sm_cmac_get_byte = get_byte_callback; 898 899 // step 2: n := ceil(len/const_Bsize); 900 sm_cmac_block_count = (sm_cmac_message_len + 15) / 16; 901 902 // step 3: .. 903 if (sm_cmac_block_count==0){ 904 sm_cmac_block_count = 1; 905 } 906 log_info("sm_cmac_general_start: len %u, block count %u", sm_cmac_message_len, sm_cmac_block_count); 907 908 // first, we need to compute l for k1, k2, and m_last 909 sm_cmac_state = CMAC_CALC_SUBKEYS; 910 911 // let's go 912 sm_run(); 913 } 914 915 // cmac for ATT Message signing 916 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)){ 917 // ATT Message Signing 918 sm_cmac_header[0] = opcode; 919 little_endian_store_16(sm_cmac_header, 1, con_handle); 920 little_endian_store_32(sm_cmac_sign_counter, 0, sign_counter); 921 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 922 sm_cmac_message = message; 923 sm_cmac_general_start(k, total_message_len, &sm_cmac_message_get_byte, done_handler); 924 } 925 926 int sm_cmac_ready(void){ 927 return sm_cmac_state == CMAC_IDLE; 928 } 929 930 static void sm_cmac_handle_aes_engine_ready(void){ 931 switch (sm_cmac_state){ 932 case CMAC_CALC_SUBKEYS: { 933 sm_key_t const_zero; 934 memset(const_zero, 0, 16); 935 sm_cmac_next_state(); 936 sm_aes128_start(sm_cmac_k, const_zero, NULL); 937 break; 938 } 939 case CMAC_CALC_MI: { 940 int j; 941 sm_key_t y; 942 for (j=0;j<16;j++){ 943 y[j] = sm_cmac_x[j] ^ sm_cmac_get_byte(sm_cmac_block_current*16 + j); 944 } 945 sm_cmac_block_current++; 946 sm_cmac_next_state(); 947 sm_aes128_start(sm_cmac_k, y, NULL); 948 break; 949 } 950 case CMAC_CALC_MLAST: { 951 int i; 952 sm_key_t y; 953 for (i=0;i<16;i++){ 954 y[i] = sm_cmac_x[i] ^ sm_cmac_m_last[i]; 955 } 956 log_info_key("Y", y); 957 sm_cmac_block_current++; 958 sm_cmac_next_state(); 959 sm_aes128_start(sm_cmac_k, y, NULL); 960 break; 961 } 962 default: 963 log_info("sm_cmac_handle_aes_engine_ready called in state %u", sm_cmac_state); 964 break; 965 } 966 } 967 968 static void sm_cmac_handle_encryption_result(sm_key_t data){ 969 switch (sm_cmac_state){ 970 case CMAC_W4_SUBKEYS: { 971 sm_key_t k1; 972 memcpy(k1, data, 16); 973 sm_shift_left_by_one_bit_inplace(16, k1); 974 if (data[0] & 0x80){ 975 k1[15] ^= 0x87; 976 } 977 sm_key_t k2; 978 memcpy(k2, k1, 16); 979 sm_shift_left_by_one_bit_inplace(16, k2); 980 if (k1[0] & 0x80){ 981 k2[15] ^= 0x87; 982 } 983 984 log_info_key("k", sm_cmac_k); 985 log_info_key("k1", k1); 986 log_info_key("k2", k2); 987 988 // step 4: set m_last 989 int i; 990 if (sm_cmac_last_block_complete()){ 991 for (i=0;i<16;i++){ 992 sm_cmac_m_last[i] = sm_cmac_get_byte(sm_cmac_message_len - 16 + i) ^ k1[i]; 993 } 994 } else { 995 int valid_octets_in_last_block = sm_cmac_message_len & 0x0f; 996 for (i=0;i<16;i++){ 997 if (i < valid_octets_in_last_block){ 998 sm_cmac_m_last[i] = sm_cmac_get_byte((sm_cmac_message_len & 0xfff0) + i) ^ k2[i]; 999 continue; 1000 } 1001 if (i == valid_octets_in_last_block){ 1002 sm_cmac_m_last[i] = 0x80 ^ k2[i]; 1003 continue; 1004 } 1005 sm_cmac_m_last[i] = k2[i]; 1006 } 1007 } 1008 1009 // next 1010 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1011 break; 1012 } 1013 case CMAC_W4_MI: 1014 memcpy(sm_cmac_x, data, 16); 1015 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1016 break; 1017 case CMAC_W4_MLAST: 1018 // done 1019 log_info("Setting CMAC Engine to IDLE"); 1020 sm_cmac_state = CMAC_IDLE; 1021 log_info_key("CMAC", data); 1022 sm_cmac_done_handler(data); 1023 break; 1024 default: 1025 log_info("sm_cmac_handle_encryption_result called in state %u", sm_cmac_state); 1026 break; 1027 } 1028 } 1029 1030 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 1031 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 1032 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 1033 switch (setup->sm_stk_generation_method){ 1034 case PK_RESP_INPUT: 1035 if (sm_conn->sm_role){ 1036 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1037 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1038 } else { 1039 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)); 1040 } 1041 break; 1042 case PK_INIT_INPUT: 1043 if (sm_conn->sm_role){ 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 } else { 1046 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1047 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1048 } 1049 break; 1050 case OK_BOTH_INPUT: 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 break; 1054 case NK_BOTH_INPUT: 1055 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1056 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)); 1057 break; 1058 case JUST_WORKS: 1059 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1060 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1061 break; 1062 case OOB: 1063 // client already provided OOB data, let's skip notification. 1064 break; 1065 } 1066 } 1067 1068 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 1069 int recv_flags; 1070 if (sm_conn->sm_role){ 1071 // slave / responder 1072 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 1073 } else { 1074 // master / initiator 1075 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 1076 } 1077 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1078 return recv_flags == setup->sm_key_distribution_received_set; 1079 } 1080 1081 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1082 if (sm_active_connection == con_handle){ 1083 sm_timeout_stop(); 1084 sm_active_connection = 0; 1085 log_info("sm: connection 0x%x released setup context", con_handle); 1086 } 1087 } 1088 1089 static int sm_key_distribution_flags_for_auth_req(void){ 1090 int flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_SIGN; 1091 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1092 // encryption information only if bonding requested 1093 flags |= SM_KEYDIST_ENC_KEY; 1094 } 1095 return flags; 1096 } 1097 1098 static void sm_init_setup(sm_connection_t * sm_conn){ 1099 1100 // fill in sm setup 1101 setup->sm_state_vars = 0; 1102 setup->sm_keypress_notification = 0xff; 1103 sm_reset_tk(); 1104 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1105 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1106 1107 // query client for OOB data 1108 int have_oob_data = 0; 1109 if (sm_get_oob_data) { 1110 have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1111 } 1112 1113 sm_pairing_packet_t * local_packet; 1114 if (sm_conn->sm_role){ 1115 // slave 1116 local_packet = &setup->sm_s_pres; 1117 gap_advertisements_get_address(&setup->sm_s_addr_type, setup->sm_s_address); 1118 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1119 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1120 } else { 1121 // master 1122 local_packet = &setup->sm_m_preq; 1123 gap_advertisements_get_address(&setup->sm_m_addr_type, setup->sm_m_address); 1124 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1125 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1126 1127 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1128 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1129 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1130 } 1131 1132 uint8_t auth_req = sm_auth_req; 1133 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1134 sm_pairing_packet_set_oob_data_flag(*local_packet, have_oob_data); 1135 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1136 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1137 } 1138 1139 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1140 1141 sm_pairing_packet_t * remote_packet; 1142 int remote_key_request; 1143 if (sm_conn->sm_role){ 1144 // slave / responder 1145 remote_packet = &setup->sm_m_preq; 1146 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1147 } else { 1148 // master / initiator 1149 remote_packet = &setup->sm_s_pres; 1150 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1151 } 1152 1153 // check key size 1154 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1155 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1156 1157 // decide on STK generation method 1158 sm_setup_tk(); 1159 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1160 1161 // check if STK generation method is acceptable by client 1162 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1163 1164 // identical to responder 1165 sm_setup_key_distribution(remote_key_request); 1166 1167 // JUST WORKS doens't provide authentication 1168 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1169 1170 return 0; 1171 } 1172 1173 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1174 1175 // cache and reset context 1176 int matched_device_id = sm_address_resolution_test; 1177 address_resolution_mode_t mode = sm_address_resolution_mode; 1178 void * context = sm_address_resolution_context; 1179 1180 // reset context 1181 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1182 sm_address_resolution_context = NULL; 1183 sm_address_resolution_test = -1; 1184 hci_con_handle_t con_handle = 0; 1185 1186 sm_connection_t * sm_connection; 1187 uint16_t ediv; 1188 switch (mode){ 1189 case ADDRESS_RESOLUTION_GENERAL: 1190 break; 1191 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1192 sm_connection = (sm_connection_t *) context; 1193 con_handle = sm_connection->sm_handle; 1194 switch (event){ 1195 case ADDRESS_RESOLUTION_SUCEEDED: 1196 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1197 sm_connection->sm_le_db_index = matched_device_id; 1198 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1199 if (sm_connection->sm_role) break; 1200 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1201 sm_connection->sm_security_request_received = 0; 1202 sm_connection->sm_bonding_requested = 0; 1203 le_device_db_encryption_get(sm_connection->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 1204 if (ediv){ 1205 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1206 } else { 1207 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1208 } 1209 break; 1210 case ADDRESS_RESOLUTION_FAILED: 1211 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1212 if (sm_connection->sm_role) break; 1213 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1214 sm_connection->sm_security_request_received = 0; 1215 sm_connection->sm_bonding_requested = 0; 1216 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1217 break; 1218 } 1219 break; 1220 default: 1221 break; 1222 } 1223 1224 switch (event){ 1225 case ADDRESS_RESOLUTION_SUCEEDED: 1226 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1227 break; 1228 case ADDRESS_RESOLUTION_FAILED: 1229 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1230 break; 1231 } 1232 } 1233 1234 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1235 1236 int le_db_index = -1; 1237 1238 // lookup device based on IRK 1239 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1240 int i; 1241 for (i=0; i < le_device_db_count(); i++){ 1242 sm_key_t irk; 1243 bd_addr_t address; 1244 int address_type; 1245 le_device_db_info(i, &address_type, address, irk); 1246 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1247 log_info("sm: device found for IRK, updating"); 1248 le_db_index = i; 1249 break; 1250 } 1251 } 1252 } 1253 1254 // if not found, lookup via public address if possible 1255 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1256 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1257 int i; 1258 for (i=0; i < le_device_db_count(); i++){ 1259 bd_addr_t address; 1260 int address_type; 1261 le_device_db_info(i, &address_type, address, NULL); 1262 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1263 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1264 log_info("sm: device found for public address, updating"); 1265 le_db_index = i; 1266 break; 1267 } 1268 } 1269 } 1270 1271 // if not found, add to db 1272 if (le_db_index < 0) { 1273 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1274 } 1275 1276 if (le_db_index >= 0){ 1277 le_device_db_local_counter_set(le_db_index, 0); 1278 1279 // store local CSRK 1280 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1281 log_info("sm: store local CSRK"); 1282 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1283 le_device_db_local_counter_set(le_db_index, 0); 1284 } 1285 1286 // store remote CSRK 1287 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1288 log_info("sm: store remote CSRK"); 1289 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1290 le_device_db_remote_counter_set(le_db_index, 0); 1291 } 1292 1293 // store encryption information 1294 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION 1295 && setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 1296 log_info("sm: set encryption information (key size %u, authenticatd %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1297 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1298 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1299 } 1300 } 1301 1302 // keep le_db_index 1303 sm_conn->sm_le_db_index = le_db_index; 1304 } 1305 1306 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1307 setup->sm_pairing_failed_reason = reason; 1308 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1309 } 1310 1311 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1312 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1313 } 1314 1315 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1316 1317 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1318 static int sm_passkey_used(stk_generation_method_t method); 1319 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1320 1321 static void sm_log_ec_keypair(void){ 1322 log_info("Elliptic curve: d"); 1323 log_info_hexdump(ec_d,32); 1324 log_info("Elliptic curve: X"); 1325 log_info_hexdump(ec_qx,32); 1326 log_info("Elliptic curve: Y"); 1327 log_info_hexdump(ec_qy,32); 1328 } 1329 1330 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1331 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1332 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1333 } else { 1334 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1335 } 1336 } 1337 1338 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1339 if (sm_conn->sm_role){ 1340 // Responder 1341 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1342 } else { 1343 // Initiator role 1344 switch (setup->sm_stk_generation_method){ 1345 case JUST_WORKS: 1346 sm_sc_prepare_dhkey_check(sm_conn); 1347 break; 1348 1349 case NK_BOTH_INPUT: 1350 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1351 break; 1352 case PK_INIT_INPUT: 1353 case PK_RESP_INPUT: 1354 case OK_BOTH_INPUT: 1355 if (setup->sm_passkey_bit < 20) { 1356 sm_sc_start_calculating_local_confirm(sm_conn); 1357 } else { 1358 sm_sc_prepare_dhkey_check(sm_conn); 1359 } 1360 break; 1361 case OOB: 1362 // TODO: implement SC OOB 1363 break; 1364 } 1365 } 1366 } 1367 1368 static uint8_t sm_sc_cmac_get_byte(uint16_t offset){ 1369 return sm_cmac_sc_buffer[offset]; 1370 } 1371 1372 static void sm_sc_cmac_done(uint8_t * hash){ 1373 log_info("sm_sc_cmac_done: "); 1374 log_info_hexdump(hash, 16); 1375 1376 sm_connection_t * sm_conn = sm_cmac_connection; 1377 sm_cmac_connection = NULL; 1378 1379 switch (sm_conn->sm_engine_state){ 1380 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1381 memcpy(setup->sm_local_confirm, hash, 16); 1382 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1383 break; 1384 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1385 // check 1386 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1387 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1388 break; 1389 } 1390 sm_sc_state_after_receiving_random(sm_conn); 1391 break; 1392 case SM_SC_W4_CALCULATE_G2: { 1393 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1394 big_endian_store_32(setup->sm_tk, 12, vab); 1395 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1396 sm_trigger_user_response(sm_conn); 1397 break; 1398 } 1399 case SM_SC_W4_CALCULATE_F5_SALT: 1400 memcpy(setup->sm_t, hash, 16); 1401 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1402 break; 1403 case SM_SC_W4_CALCULATE_F5_MACKEY: 1404 memcpy(setup->sm_mackey, hash, 16); 1405 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1406 break; 1407 case SM_SC_W4_CALCULATE_F5_LTK: 1408 memcpy(setup->sm_ltk, hash, 16); 1409 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1410 break; 1411 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1412 memcpy(setup->sm_local_dhkey_check, hash, 16); 1413 if (sm_conn->sm_role){ 1414 // responder 1415 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1416 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1417 } else { 1418 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1419 } 1420 } else { 1421 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1422 } 1423 break; 1424 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1425 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1426 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1427 break; 1428 } 1429 if (sm_conn->sm_role){ 1430 // responder 1431 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1432 } else { 1433 // initiator 1434 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1435 } 1436 break; 1437 default: 1438 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1439 break; 1440 } 1441 sm_run(); 1442 } 1443 1444 static void f4_engine(sm_connection_t * sm_conn, const sm_key256_t u, const sm_key256_t v, const sm_key_t x, uint8_t z){ 1445 const uint16_t message_len = 65; 1446 sm_cmac_connection = sm_conn; 1447 memcpy(sm_cmac_sc_buffer, u, 32); 1448 memcpy(sm_cmac_sc_buffer+32, v, 32); 1449 sm_cmac_sc_buffer[64] = z; 1450 log_info("f4 key"); 1451 log_info_hexdump(x, 16); 1452 log_info("f4 message"); 1453 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1454 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1455 } 1456 1457 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1458 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1459 static const uint8_t f5_length[] = { 0x01, 0x00}; 1460 1461 static void sm_sc_calculate_dhkey(sm_key256_t dhkey){ 1462 #ifdef USE_MBEDTLS_FOR_ECDH 1463 // da * Pb 1464 mbedtls_mpi d; 1465 mbedtls_ecp_point Q; 1466 mbedtls_ecp_point DH; 1467 mbedtls_mpi_init(&d); 1468 mbedtls_ecp_point_init(&Q); 1469 mbedtls_ecp_point_init(&DH); 1470 mbedtls_mpi_read_binary(&d, ec_d, 32); 1471 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 1472 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 1473 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 1474 mbedtls_ecp_mul(&mbedtls_ec_group, &DH, &d, &Q, NULL, NULL); 1475 mbedtls_mpi_write_binary(&DH.X, dhkey, 32); 1476 mbedtls_mpi_free(&d); 1477 mbedtls_ecp_point_free(&Q); 1478 mbedtls_ecp_point_free(&DH); 1479 #endif 1480 log_info("dhkey"); 1481 log_info_hexdump(dhkey, 32); 1482 } 1483 1484 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1485 // calculate DHKEY 1486 sm_key256_t dhkey; 1487 sm_sc_calculate_dhkey(dhkey); 1488 1489 // calculate salt for f5 1490 const uint16_t message_len = 32; 1491 sm_cmac_connection = sm_conn; 1492 memcpy(sm_cmac_sc_buffer, dhkey, message_len); 1493 sm_cmac_general_start(f5_salt, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1494 } 1495 1496 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){ 1497 const uint16_t message_len = 53; 1498 sm_cmac_connection = sm_conn; 1499 1500 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1501 sm_cmac_sc_buffer[0] = 0; 1502 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1503 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1504 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1505 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1506 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1507 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1508 log_info("f5 key"); 1509 log_info_hexdump(t, 16); 1510 log_info("f5 message for MacKey"); 1511 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1512 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1513 } 1514 1515 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1516 sm_key56_t bd_addr_master, bd_addr_slave; 1517 bd_addr_master[0] = setup->sm_m_addr_type; 1518 bd_addr_slave[0] = setup->sm_s_addr_type; 1519 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1520 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1521 if (sm_conn->sm_role){ 1522 // responder 1523 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1524 } else { 1525 // initiator 1526 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1527 } 1528 } 1529 1530 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1531 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1532 const uint16_t message_len = 53; 1533 sm_cmac_connection = sm_conn; 1534 sm_cmac_sc_buffer[0] = 1; 1535 // 1..52 setup before 1536 log_info("f5 key"); 1537 log_info_hexdump(t, 16); 1538 log_info("f5 message for LTK"); 1539 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1540 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1541 } 1542 1543 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1544 f5_ltk(sm_conn, setup->sm_t); 1545 } 1546 1547 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){ 1548 const uint16_t message_len = 65; 1549 sm_cmac_connection = sm_conn; 1550 memcpy(sm_cmac_sc_buffer, n1, 16); 1551 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1552 memcpy(sm_cmac_sc_buffer+32, r, 16); 1553 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1554 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1555 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1556 log_info("f6 key"); 1557 log_info_hexdump(w, 16); 1558 log_info("f6 message"); 1559 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1560 sm_cmac_general_start(w, 65, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1561 } 1562 1563 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1564 // - U is 256 bits 1565 // - V is 256 bits 1566 // - X is 128 bits 1567 // - Y is 128 bits 1568 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){ 1569 const uint16_t message_len = 80; 1570 sm_cmac_connection = sm_conn; 1571 memcpy(sm_cmac_sc_buffer, u, 32); 1572 memcpy(sm_cmac_sc_buffer+32, v, 32); 1573 memcpy(sm_cmac_sc_buffer+64, y, 16); 1574 log_info("g2 key"); 1575 log_info_hexdump(x, 16); 1576 log_info("g2 message"); 1577 log_info_hexdump(sm_cmac_sc_buffer, sizeof(sm_cmac_sc_buffer)); 1578 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1579 } 1580 1581 static void g2_calculate(sm_connection_t * sm_conn) { 1582 // calc Va if numeric comparison 1583 if (sm_conn->sm_role){ 1584 // responder 1585 g2_engine(sm_conn, setup->sm_peer_qx, ec_qx, setup->sm_peer_nonce, setup->sm_local_nonce);; 1586 } else { 1587 // initiator 1588 g2_engine(sm_conn, ec_qx, setup->sm_peer_qx, setup->sm_local_nonce, setup->sm_peer_nonce); 1589 } 1590 } 1591 1592 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1593 uint8_t z = 0; 1594 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1595 // some form of passkey 1596 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1597 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1598 setup->sm_passkey_bit++; 1599 } 1600 f4_engine(sm_conn, ec_qx, setup->sm_peer_qx, setup->sm_local_nonce, z); 1601 } 1602 1603 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1604 uint8_t z = 0; 1605 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1606 // some form of passkey 1607 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1608 // sm_passkey_bit was increased before sending confirm value 1609 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1610 } 1611 f4_engine(sm_conn, setup->sm_peer_qx, ec_qx, setup->sm_peer_nonce, z); 1612 } 1613 1614 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1615 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1616 } 1617 1618 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1619 // calculate DHKCheck 1620 sm_key56_t bd_addr_master, bd_addr_slave; 1621 bd_addr_master[0] = setup->sm_m_addr_type; 1622 bd_addr_slave[0] = setup->sm_s_addr_type; 1623 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1624 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1625 uint8_t iocap_a[3]; 1626 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1627 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1628 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1629 uint8_t iocap_b[3]; 1630 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1631 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1632 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1633 if (sm_conn->sm_role){ 1634 // responder 1635 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); 1636 } else { 1637 // initiator 1638 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); 1639 } 1640 } 1641 1642 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1643 // validate E = f6() 1644 sm_key56_t bd_addr_master, bd_addr_slave; 1645 bd_addr_master[0] = setup->sm_m_addr_type; 1646 bd_addr_slave[0] = setup->sm_s_addr_type; 1647 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1648 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1649 1650 uint8_t iocap_a[3]; 1651 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1652 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1653 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1654 uint8_t iocap_b[3]; 1655 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1656 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1657 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1658 if (sm_conn->sm_role){ 1659 // responder 1660 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); 1661 } else { 1662 // initiator 1663 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); 1664 } 1665 } 1666 #endif 1667 1668 static void sm_load_security_info(sm_connection_t * sm_connection){ 1669 int encryption_key_size; 1670 int authenticated; 1671 int authorized; 1672 1673 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1674 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1675 &encryption_key_size, &authenticated, &authorized); 1676 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1677 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1678 sm_connection->sm_connection_authenticated = authenticated; 1679 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1680 } 1681 1682 static void sm_run(void){ 1683 1684 btstack_linked_list_iterator_t it; 1685 1686 // assert that we can send at least commands 1687 if (!hci_can_send_command_packet_now()) return; 1688 1689 // 1690 // non-connection related behaviour 1691 // 1692 1693 // distributed key generation 1694 switch (dkg_state){ 1695 case DKG_CALC_IRK: 1696 // already busy? 1697 if (sm_aes128_state == SM_AES128_IDLE) { 1698 // IRK = d1(IR, 1, 0) 1699 sm_key_t d1_prime; 1700 sm_d1_d_prime(1, 0, d1_prime); // plaintext 1701 dkg_next_state(); 1702 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1703 return; 1704 } 1705 break; 1706 case DKG_CALC_DHK: 1707 // already busy? 1708 if (sm_aes128_state == SM_AES128_IDLE) { 1709 // DHK = d1(IR, 3, 0) 1710 sm_key_t d1_prime; 1711 sm_d1_d_prime(3, 0, d1_prime); // plaintext 1712 dkg_next_state(); 1713 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1714 return; 1715 } 1716 break; 1717 default: 1718 break; 1719 } 1720 1721 #ifdef USE_MBEDTLS_FOR_ECDH 1722 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 1723 sm_random_start(NULL); 1724 return; 1725 } 1726 #endif 1727 1728 // random address updates 1729 switch (rau_state){ 1730 case RAU_GET_RANDOM: 1731 rau_next_state(); 1732 sm_random_start(NULL); 1733 return; 1734 case RAU_GET_ENC: 1735 // already busy? 1736 if (sm_aes128_state == SM_AES128_IDLE) { 1737 sm_key_t r_prime; 1738 sm_ah_r_prime(sm_random_address, r_prime); 1739 rau_next_state(); 1740 sm_aes128_start(sm_persistent_irk, r_prime, NULL); 1741 return; 1742 } 1743 break; 1744 case RAU_SET_ADDRESS: 1745 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1746 rau_state = RAU_IDLE; 1747 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1748 return; 1749 default: 1750 break; 1751 } 1752 1753 // CMAC 1754 switch (sm_cmac_state){ 1755 case CMAC_CALC_SUBKEYS: 1756 case CMAC_CALC_MI: 1757 case CMAC_CALC_MLAST: 1758 // already busy? 1759 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1760 sm_cmac_handle_aes_engine_ready(); 1761 return; 1762 default: 1763 break; 1764 } 1765 1766 // CSRK Lookup 1767 // -- if csrk lookup ready, find connection that require csrk lookup 1768 if (sm_address_resolution_idle()){ 1769 hci_connections_get_iterator(&it); 1770 while(btstack_linked_list_iterator_has_next(&it)){ 1771 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1772 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1773 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1774 // and start lookup 1775 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); 1776 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1777 break; 1778 } 1779 } 1780 } 1781 1782 // -- if csrk lookup ready, resolved addresses for received addresses 1783 if (sm_address_resolution_idle()) { 1784 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1785 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1786 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1787 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1788 btstack_memory_sm_lookup_entry_free(entry); 1789 } 1790 } 1791 1792 // -- Continue with CSRK device lookup by public or resolvable private address 1793 if (!sm_address_resolution_idle()){ 1794 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_count()); 1795 while (sm_address_resolution_test < le_device_db_count()){ 1796 int addr_type; 1797 bd_addr_t addr; 1798 sm_key_t irk; 1799 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1800 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1801 1802 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1803 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1804 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1805 break; 1806 } 1807 1808 if (sm_address_resolution_addr_type == 0){ 1809 sm_address_resolution_test++; 1810 continue; 1811 } 1812 1813 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1814 1815 log_info("LE Device Lookup: calculate AH"); 1816 log_info_key("IRK", irk); 1817 1818 sm_key_t r_prime; 1819 sm_ah_r_prime(sm_address_resolution_address, r_prime); 1820 sm_address_resolution_ah_calculation_active = 1; 1821 sm_aes128_start(irk, r_prime, sm_address_resolution_context); // keep context 1822 return; 1823 } 1824 1825 if (sm_address_resolution_test >= le_device_db_count()){ 1826 log_info("LE Device Lookup: not found"); 1827 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1828 } 1829 } 1830 1831 1832 // 1833 // active connection handling 1834 // -- use loop to handle next connection if lock on setup context is released 1835 1836 while (1) { 1837 1838 // Find connections that requires setup context and make active if no other is locked 1839 hci_connections_get_iterator(&it); 1840 while(!sm_active_connection && btstack_linked_list_iterator_has_next(&it)){ 1841 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1842 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1843 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 1844 int done = 1; 1845 int err; 1846 switch (sm_connection->sm_engine_state) { 1847 case SM_RESPONDER_SEND_SECURITY_REQUEST: 1848 // send packet if possible, 1849 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 1850 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 1851 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 1852 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1853 } else { 1854 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1855 } 1856 // don't lock sxetup context yet 1857 done = 0; 1858 break; 1859 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 1860 sm_init_setup(sm_connection); 1861 // recover pairing request 1862 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 1863 err = sm_stk_generation_init(sm_connection); 1864 if (err){ 1865 setup->sm_pairing_failed_reason = err; 1866 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1867 break; 1868 } 1869 sm_timeout_start(sm_connection); 1870 // generate random number first, if we need to show passkey 1871 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 1872 sm_connection->sm_engine_state = SM_PH2_GET_RANDOM_TK; 1873 break; 1874 } 1875 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 1876 break; 1877 case SM_INITIATOR_PH0_HAS_LTK: 1878 sm_load_security_info(sm_connection); 1879 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 1880 break; 1881 case SM_RESPONDER_PH0_RECEIVED_LTK: 1882 switch (sm_connection->sm_irk_lookup_state){ 1883 case IRK_LOOKUP_SUCCEEDED:{ 1884 sm_load_security_info(sm_connection); 1885 sm_connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 1886 break; 1887 } 1888 case IRK_LOOKUP_FAILED: 1889 // assume that we don't have a LTK for ediv == 0 and random == null 1890 if (sm_connection->sm_local_ediv == 0 && sm_is_null_random(sm_connection->sm_local_rand)){ 1891 log_info("LTK Request: ediv & random are empty"); 1892 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1893 // TODO: no need to lock context yet -> done = 0; 1894 break; 1895 } 1896 // re-establish previously used LTK using Rand and EDIV 1897 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1898 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1899 // re-establish used key encryption size 1900 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1901 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1902 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1903 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1904 log_info("sm: received ltk request with key size %u, authenticated %u", 1905 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1906 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1907 break; 1908 default: 1909 // just wait until IRK lookup is completed 1910 // don't lock sxetup context yet 1911 done = 0; 1912 break; 1913 } 1914 break; 1915 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 1916 sm_init_setup(sm_connection); 1917 sm_timeout_start(sm_connection); 1918 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 1919 break; 1920 default: 1921 done = 0; 1922 break; 1923 } 1924 if (done){ 1925 sm_active_connection = sm_connection->sm_handle; 1926 log_info("sm: connection 0x%04x locked setup context as %s", sm_active_connection, sm_connection->sm_role ? "responder" : "initiator"); 1927 } 1928 } 1929 1930 // 1931 // active connection handling 1932 // 1933 1934 if (sm_active_connection == 0) return; 1935 1936 // assert that we could send a SM PDU - not needed for all of the following 1937 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 1938 l2cap_request_can_send_fix_channel_now_event(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1939 return; 1940 } 1941 1942 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection); 1943 if (!connection) return; 1944 1945 // send keypress notifications 1946 if (setup->sm_keypress_notification != 0xff){ 1947 uint8_t buffer[2]; 1948 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 1949 buffer[1] = setup->sm_keypress_notification; 1950 setup->sm_keypress_notification = 0xff; 1951 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1952 } 1953 1954 sm_key_t plaintext; 1955 int key_distribution_flags; 1956 1957 log_info("sm_run: state %u", connection->sm_engine_state); 1958 1959 // responding state 1960 switch (connection->sm_engine_state){ 1961 1962 // general 1963 case SM_GENERAL_SEND_PAIRING_FAILED: { 1964 uint8_t buffer[2]; 1965 buffer[0] = SM_CODE_PAIRING_FAILED; 1966 buffer[1] = setup->sm_pairing_failed_reason; 1967 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 1968 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1969 sm_done_for_handle(connection->sm_handle); 1970 break; 1971 } 1972 1973 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1974 case SM_SC_W2_GET_RANDOM_A: 1975 sm_random_start(connection); 1976 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_A; 1977 break; 1978 case SM_SC_W2_GET_RANDOM_B: 1979 sm_random_start(connection); 1980 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_B; 1981 break; 1982 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 1983 if (!sm_cmac_ready()) break; 1984 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 1985 sm_sc_calculate_local_confirm(connection); 1986 break; 1987 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 1988 if (!sm_cmac_ready()) break; 1989 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 1990 sm_sc_calculate_remote_confirm(connection); 1991 break; 1992 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 1993 if (!sm_cmac_ready()) break; 1994 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 1995 sm_sc_calculate_f6_for_dhkey_check(connection); 1996 break; 1997 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1998 if (!sm_cmac_ready()) break; 1999 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2000 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2001 break; 2002 case SM_SC_W2_CALCULATE_F5_SALT: 2003 if (!sm_cmac_ready()) break; 2004 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2005 f5_calculate_salt(connection); 2006 break; 2007 case SM_SC_W2_CALCULATE_F5_MACKEY: 2008 if (!sm_cmac_ready()) break; 2009 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2010 f5_calculate_mackey(connection); 2011 break; 2012 case SM_SC_W2_CALCULATE_F5_LTK: 2013 if (!sm_cmac_ready()) break; 2014 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2015 f5_calculate_ltk(connection); 2016 break; 2017 case SM_SC_W2_CALCULATE_G2: 2018 if (!sm_cmac_ready()) break; 2019 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2020 g2_calculate(connection); 2021 break; 2022 2023 #endif 2024 // initiator side 2025 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2026 sm_key_t peer_ltk_flipped; 2027 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2028 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2029 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2030 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2031 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2032 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2033 return; 2034 } 2035 2036 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2037 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2038 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2039 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2040 sm_timeout_reset(connection); 2041 break; 2042 2043 // responder side 2044 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2045 connection->sm_engine_state = SM_RESPONDER_IDLE; 2046 hci_send_cmd(&hci_le_long_term_key_negative_reply, connection->sm_handle); 2047 sm_done_for_handle(connection->sm_handle); 2048 return; 2049 2050 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2051 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2052 uint8_t buffer[65]; 2053 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2054 // 2055 reverse_256(ec_qx, &buffer[1]); 2056 reverse_256(ec_qy, &buffer[33]); 2057 2058 // stk generation method 2059 // passkey entry: notify app to show passkey or to request passkey 2060 switch (setup->sm_stk_generation_method){ 2061 case JUST_WORKS: 2062 case NK_BOTH_INPUT: 2063 if (connection->sm_role){ 2064 // responder 2065 sm_sc_start_calculating_local_confirm(connection); 2066 } else { 2067 // initiator 2068 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2069 } 2070 break; 2071 case PK_INIT_INPUT: 2072 case PK_RESP_INPUT: 2073 case OK_BOTH_INPUT: 2074 // use random TK for display 2075 memcpy(setup->sm_ra, setup->sm_tk, 16); 2076 memcpy(setup->sm_rb, setup->sm_tk, 16); 2077 setup->sm_passkey_bit = 0; 2078 2079 if (connection->sm_role){ 2080 // responder 2081 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2082 } else { 2083 // initiator 2084 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2085 } 2086 sm_trigger_user_response(connection); 2087 break; 2088 case OOB: 2089 // TODO: implement SC OOB 2090 break; 2091 } 2092 2093 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2094 sm_timeout_reset(connection); 2095 break; 2096 } 2097 case SM_SC_SEND_CONFIRMATION: { 2098 uint8_t buffer[17]; 2099 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2100 reverse_128(setup->sm_local_confirm, &buffer[1]); 2101 if (connection->sm_role){ 2102 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2103 } else { 2104 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2105 } 2106 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2107 sm_timeout_reset(connection); 2108 break; 2109 } 2110 case SM_SC_SEND_PAIRING_RANDOM: { 2111 uint8_t buffer[17]; 2112 buffer[0] = SM_CODE_PAIRING_RANDOM; 2113 reverse_128(setup->sm_local_nonce, &buffer[1]); 2114 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT && setup->sm_passkey_bit < 20){ 2115 if (connection->sm_role){ 2116 // responder 2117 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2118 } else { 2119 // initiator 2120 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2121 } 2122 } else { 2123 if (connection->sm_role){ 2124 // responder 2125 if (setup->sm_stk_generation_method == NK_BOTH_INPUT){ 2126 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2127 } else { 2128 sm_sc_prepare_dhkey_check(connection); 2129 } 2130 } else { 2131 // initiator 2132 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2133 } 2134 } 2135 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2136 sm_timeout_reset(connection); 2137 break; 2138 } 2139 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2140 uint8_t buffer[17]; 2141 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2142 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2143 2144 if (connection->sm_role){ 2145 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2146 } else { 2147 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2148 } 2149 2150 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2151 sm_timeout_reset(connection); 2152 break; 2153 } 2154 2155 #endif 2156 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2157 // echo initiator for now 2158 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2159 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2160 2161 if (setup->sm_use_secure_connections){ 2162 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2163 // skip LTK/EDIV for SC 2164 log_info("sm: dropping encryption information flag"); 2165 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2166 } else { 2167 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2168 } 2169 2170 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); 2171 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); 2172 // update key distribution after ENC was dropped 2173 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2174 2175 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2176 sm_timeout_reset(connection); 2177 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2178 if (!setup->sm_use_secure_connections || setup->sm_stk_generation_method == JUST_WORKS){ 2179 sm_trigger_user_response(connection); 2180 } 2181 return; 2182 2183 case SM_PH2_SEND_PAIRING_RANDOM: { 2184 uint8_t buffer[17]; 2185 buffer[0] = SM_CODE_PAIRING_RANDOM; 2186 reverse_128(setup->sm_local_random, &buffer[1]); 2187 if (connection->sm_role){ 2188 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2189 } else { 2190 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2191 } 2192 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2193 sm_timeout_reset(connection); 2194 break; 2195 } 2196 2197 case SM_PH2_GET_RANDOM_TK: 2198 case SM_PH2_C1_GET_RANDOM_A: 2199 case SM_PH2_C1_GET_RANDOM_B: 2200 case SM_PH3_GET_RANDOM: 2201 case SM_PH3_GET_DIV: 2202 sm_next_responding_state(connection); 2203 sm_random_start(connection); 2204 return; 2205 2206 case SM_PH2_C1_GET_ENC_B: 2207 case SM_PH2_C1_GET_ENC_D: 2208 // already busy? 2209 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2210 sm_next_responding_state(connection); 2211 sm_aes128_start(setup->sm_tk, setup->sm_c1_t3_value, connection); 2212 return; 2213 2214 case SM_PH3_LTK_GET_ENC: 2215 case SM_RESPONDER_PH4_LTK_GET_ENC: 2216 // already busy? 2217 if (sm_aes128_state == SM_AES128_IDLE) { 2218 sm_key_t d_prime; 2219 sm_d1_d_prime(setup->sm_local_div, 0, d_prime); 2220 sm_next_responding_state(connection); 2221 sm_aes128_start(sm_persistent_er, d_prime, connection); 2222 return; 2223 } 2224 break; 2225 2226 case SM_PH3_CSRK_GET_ENC: 2227 // already busy? 2228 if (sm_aes128_state == SM_AES128_IDLE) { 2229 sm_key_t d_prime; 2230 sm_d1_d_prime(setup->sm_local_div, 1, d_prime); 2231 sm_next_responding_state(connection); 2232 sm_aes128_start(sm_persistent_er, d_prime, connection); 2233 return; 2234 } 2235 break; 2236 2237 case SM_PH2_C1_GET_ENC_C: 2238 // already busy? 2239 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2240 // calculate m_confirm using aes128 engine - step 1 2241 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); 2242 sm_next_responding_state(connection); 2243 sm_aes128_start(setup->sm_tk, plaintext, connection); 2244 break; 2245 case SM_PH2_C1_GET_ENC_A: 2246 // already busy? 2247 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2248 // calculate confirm using aes128 engine - step 1 2249 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); 2250 sm_next_responding_state(connection); 2251 sm_aes128_start(setup->sm_tk, plaintext, connection); 2252 break; 2253 case SM_PH2_CALC_STK: 2254 // already busy? 2255 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2256 // calculate STK 2257 if (connection->sm_role){ 2258 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, plaintext); 2259 } else { 2260 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, plaintext); 2261 } 2262 sm_next_responding_state(connection); 2263 sm_aes128_start(setup->sm_tk, plaintext, connection); 2264 break; 2265 case SM_PH3_Y_GET_ENC: 2266 // already busy? 2267 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2268 // PH3B2 - calculate Y from - enc 2269 // Y = dm(DHK, Rand) 2270 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2271 sm_next_responding_state(connection); 2272 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2273 return; 2274 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2275 uint8_t buffer[17]; 2276 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2277 reverse_128(setup->sm_local_confirm, &buffer[1]); 2278 if (connection->sm_role){ 2279 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2280 } else { 2281 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2282 } 2283 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2284 sm_timeout_reset(connection); 2285 return; 2286 } 2287 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2288 sm_key_t stk_flipped; 2289 reverse_128(setup->sm_ltk, stk_flipped); 2290 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2291 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2292 return; 2293 } 2294 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2295 sm_key_t stk_flipped; 2296 reverse_128(setup->sm_ltk, stk_flipped); 2297 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2298 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2299 return; 2300 } 2301 case SM_RESPONDER_PH4_SEND_LTK: { 2302 sm_key_t ltk_flipped; 2303 reverse_128(setup->sm_ltk, ltk_flipped); 2304 connection->sm_engine_state = SM_RESPONDER_IDLE; 2305 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2306 return; 2307 } 2308 case SM_RESPONDER_PH4_Y_GET_ENC: 2309 // already busy? 2310 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2311 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2312 // Y = dm(DHK, Rand) 2313 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2314 sm_next_responding_state(connection); 2315 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2316 return; 2317 2318 case SM_PH3_DISTRIBUTE_KEYS: 2319 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2320 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2321 uint8_t buffer[17]; 2322 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2323 reverse_128(setup->sm_ltk, &buffer[1]); 2324 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2325 sm_timeout_reset(connection); 2326 return; 2327 } 2328 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2329 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2330 uint8_t buffer[11]; 2331 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2332 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2333 reverse_64(setup->sm_local_rand, &buffer[3]); 2334 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2335 sm_timeout_reset(connection); 2336 return; 2337 } 2338 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2339 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2340 uint8_t buffer[17]; 2341 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2342 reverse_128(sm_persistent_irk, &buffer[1]); 2343 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2344 sm_timeout_reset(connection); 2345 return; 2346 } 2347 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2348 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2349 bd_addr_t local_address; 2350 uint8_t buffer[8]; 2351 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2352 gap_advertisements_get_address(&buffer[1], local_address); 2353 reverse_bd_addr(local_address, &buffer[2]); 2354 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2355 sm_timeout_reset(connection); 2356 return; 2357 } 2358 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2359 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2360 2361 // hack to reproduce test runs 2362 if (test_use_fixed_local_csrk){ 2363 memset(setup->sm_local_csrk, 0xcc, 16); 2364 } 2365 2366 uint8_t buffer[17]; 2367 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2368 reverse_128(setup->sm_local_csrk, &buffer[1]); 2369 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2370 sm_timeout_reset(connection); 2371 return; 2372 } 2373 2374 // keys are sent 2375 if (connection->sm_role){ 2376 // slave -> receive master keys if any 2377 if (sm_key_distribution_all_received(connection)){ 2378 sm_key_distribution_handle_all_received(connection); 2379 connection->sm_engine_state = SM_RESPONDER_IDLE; 2380 sm_done_for_handle(connection->sm_handle); 2381 } else { 2382 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2383 } 2384 } else { 2385 // master -> all done 2386 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2387 sm_done_for_handle(connection->sm_handle); 2388 } 2389 break; 2390 2391 default: 2392 break; 2393 } 2394 2395 // check again if active connection was released 2396 if (sm_active_connection) break; 2397 } 2398 } 2399 2400 // note: aes engine is ready as we just got the aes result 2401 static void sm_handle_encryption_result(uint8_t * data){ 2402 2403 sm_aes128_state = SM_AES128_IDLE; 2404 2405 if (sm_address_resolution_ah_calculation_active){ 2406 sm_address_resolution_ah_calculation_active = 0; 2407 // compare calulated address against connecting device 2408 uint8_t hash[3]; 2409 reverse_24(data, hash); 2410 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2411 log_info("LE Device Lookup: matched resolvable private address"); 2412 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2413 return; 2414 } 2415 // no match, try next 2416 sm_address_resolution_test++; 2417 return; 2418 } 2419 2420 switch (dkg_state){ 2421 case DKG_W4_IRK: 2422 reverse_128(data, sm_persistent_irk); 2423 log_info_key("irk", sm_persistent_irk); 2424 dkg_next_state(); 2425 return; 2426 case DKG_W4_DHK: 2427 reverse_128(data, sm_persistent_dhk); 2428 log_info_key("dhk", sm_persistent_dhk); 2429 dkg_next_state(); 2430 // SM Init Finished 2431 return; 2432 default: 2433 break; 2434 } 2435 2436 switch (rau_state){ 2437 case RAU_W4_ENC: 2438 reverse_24(data, &sm_random_address[3]); 2439 rau_next_state(); 2440 return; 2441 default: 2442 break; 2443 } 2444 2445 switch (sm_cmac_state){ 2446 case CMAC_W4_SUBKEYS: 2447 case CMAC_W4_MI: 2448 case CMAC_W4_MLAST: 2449 { 2450 sm_key_t t; 2451 reverse_128(data, t); 2452 sm_cmac_handle_encryption_result(t); 2453 } 2454 return; 2455 default: 2456 break; 2457 } 2458 2459 // retrieve sm_connection provided to sm_aes128_start_encryption 2460 sm_connection_t * connection = (sm_connection_t*) sm_aes128_context; 2461 if (!connection) return; 2462 switch (connection->sm_engine_state){ 2463 case SM_PH2_C1_W4_ENC_A: 2464 case SM_PH2_C1_W4_ENC_C: 2465 { 2466 sm_key_t t2; 2467 reverse_128(data, t2); 2468 sm_c1_t3(t2, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2469 } 2470 sm_next_responding_state(connection); 2471 return; 2472 case SM_PH2_C1_W4_ENC_B: 2473 reverse_128(data, setup->sm_local_confirm); 2474 log_info_key("c1!", setup->sm_local_confirm); 2475 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2476 return; 2477 case SM_PH2_C1_W4_ENC_D: 2478 { 2479 sm_key_t peer_confirm_test; 2480 reverse_128(data, peer_confirm_test); 2481 log_info_key("c1!", peer_confirm_test); 2482 if (memcmp(setup->sm_peer_confirm, peer_confirm_test, 16) != 0){ 2483 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2484 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2485 return; 2486 } 2487 if (connection->sm_role){ 2488 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2489 } else { 2490 connection->sm_engine_state = SM_PH2_CALC_STK; 2491 } 2492 } 2493 return; 2494 case SM_PH2_W4_STK: 2495 reverse_128(data, setup->sm_ltk); 2496 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2497 log_info_key("stk", setup->sm_ltk); 2498 if (connection->sm_role){ 2499 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2500 } else { 2501 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2502 } 2503 return; 2504 case SM_PH3_Y_W4_ENC:{ 2505 sm_key_t y128; 2506 reverse_128(data, y128); 2507 setup->sm_local_y = big_endian_read_16(y128, 14); 2508 log_info_hex16("y", setup->sm_local_y); 2509 // PH3B3 - calculate EDIV 2510 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2511 log_info_hex16("ediv", setup->sm_local_ediv); 2512 // PH3B4 - calculate LTK - enc 2513 // LTK = d1(ER, DIV, 0)) 2514 connection->sm_engine_state = SM_PH3_LTK_GET_ENC; 2515 return; 2516 } 2517 case SM_RESPONDER_PH4_Y_W4_ENC:{ 2518 sm_key_t y128; 2519 reverse_128(data, y128); 2520 setup->sm_local_y = big_endian_read_16(y128, 14); 2521 log_info_hex16("y", setup->sm_local_y); 2522 2523 // PH3B3 - calculate DIV 2524 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2525 log_info_hex16("ediv", setup->sm_local_ediv); 2526 // PH3B4 - calculate LTK - enc 2527 // LTK = d1(ER, DIV, 0)) 2528 connection->sm_engine_state = SM_RESPONDER_PH4_LTK_GET_ENC; 2529 return; 2530 } 2531 case SM_PH3_LTK_W4_ENC: 2532 reverse_128(data, setup->sm_ltk); 2533 log_info_key("ltk", setup->sm_ltk); 2534 // calc CSRK next 2535 connection->sm_engine_state = SM_PH3_CSRK_GET_ENC; 2536 return; 2537 case SM_PH3_CSRK_W4_ENC: 2538 reverse_128(data, setup->sm_local_csrk); 2539 log_info_key("csrk", setup->sm_local_csrk); 2540 if (setup->sm_key_distribution_send_set){ 2541 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2542 } else { 2543 // no keys to send, just continue 2544 if (connection->sm_role){ 2545 // slave -> receive master keys 2546 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2547 } else { 2548 // master -> all done 2549 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2550 sm_done_for_handle(connection->sm_handle); 2551 } 2552 } 2553 return; 2554 case SM_RESPONDER_PH4_LTK_W4_ENC: 2555 reverse_128(data, setup->sm_ltk); 2556 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2557 log_info_key("ltk", setup->sm_ltk); 2558 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK; 2559 return; 2560 default: 2561 break; 2562 } 2563 } 2564 2565 #ifdef USE_MBEDTLS_FOR_ECDH 2566 2567 static int sm_generate_f_rng(void * context, unsigned char * buffer, size_t size){ 2568 int offset = setup->sm_passkey_bit; 2569 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, offset); 2570 while (size) { 2571 if (offset < 32){ 2572 *buffer++ = setup->sm_peer_qx[offset++]; 2573 } else { 2574 *buffer++ = setup->sm_peer_qx[offset++ - 32]; 2575 } 2576 size--; 2577 } 2578 setup->sm_passkey_bit = offset; 2579 return 0; 2580 } 2581 #endif 2582 2583 // note: random generator is ready. this doesn NOT imply that aes engine is unused! 2584 static void sm_handle_random_result(uint8_t * data){ 2585 2586 #ifdef USE_MBEDTLS_FOR_ECDH 2587 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 2588 int num_bytes = setup->sm_passkey_bit; 2589 if (num_bytes < 32){ 2590 memcpy(&setup->sm_peer_qx[num_bytes], data, 8); 2591 } else { 2592 memcpy(&setup->sm_peer_qx[num_bytes-32], data, 8); 2593 } 2594 num_bytes += 8; 2595 setup->sm_passkey_bit = num_bytes; 2596 2597 if (num_bytes >= 64){ 2598 // generate EC key 2599 setup->sm_passkey_bit = 0; 2600 mbedtls_mpi d; 2601 mbedtls_ecp_point P; 2602 mbedtls_mpi_init(&d); 2603 mbedtls_ecp_point_init(&P); 2604 int res = mbedtls_ecp_gen_keypair(&mbedtls_ec_group, &d, &P, &sm_generate_f_rng, NULL); 2605 log_info("gen keypair %x", res); 2606 mbedtls_mpi_write_binary(&P.X, ec_qx, 32); 2607 mbedtls_mpi_write_binary(&P.Y, ec_qy, 32); 2608 mbedtls_mpi_write_binary(&d, ec_d, 32); 2609 mbedtls_ecp_point_free(&P); 2610 mbedtls_mpi_free(&d); 2611 ec_key_generation_state = EC_KEY_GENERATION_DONE; 2612 sm_log_ec_keypair(); 2613 2614 #if 0 2615 printf("test dhkey check\n"); 2616 sm_key256_t dhkey; 2617 memcpy(setup->sm_peer_qx, ec_qx, 32); 2618 memcpy(setup->sm_peer_qy, ec_qy, 32); 2619 sm_sc_calculate_dhkey(dhkey); 2620 #endif 2621 2622 } 2623 } 2624 #endif 2625 2626 switch (rau_state){ 2627 case RAU_W4_RANDOM: 2628 // non-resolvable vs. resolvable 2629 switch (gap_random_adress_type){ 2630 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2631 // resolvable: use random as prand and calc address hash 2632 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2633 memcpy(sm_random_address, data, 3); 2634 sm_random_address[0] &= 0x3f; 2635 sm_random_address[0] |= 0x40; 2636 rau_state = RAU_GET_ENC; 2637 break; 2638 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2639 default: 2640 // "The two most significant bits of the address shall be equal to ‘0’"" 2641 memcpy(sm_random_address, data, 6); 2642 sm_random_address[0] &= 0x3f; 2643 rau_state = RAU_SET_ADDRESS; 2644 break; 2645 } 2646 return; 2647 default: 2648 break; 2649 } 2650 2651 // retrieve sm_connection provided to sm_random_start 2652 sm_connection_t * connection = (sm_connection_t *) sm_random_context; 2653 if (!connection) return; 2654 switch (connection->sm_engine_state){ 2655 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2656 case SM_SC_W4_GET_RANDOM_A: 2657 memcpy(&setup->sm_local_nonce[0], data, 8); 2658 connection->sm_engine_state = SM_SC_W2_GET_RANDOM_B; 2659 break; 2660 case SM_SC_W4_GET_RANDOM_B: 2661 memcpy(&setup->sm_local_nonce[8], data, 8); 2662 // initiator & jw/nc -> send pairing random 2663 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2664 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2665 break; 2666 } else { 2667 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2668 } 2669 break; 2670 #endif 2671 2672 case SM_PH2_W4_RANDOM_TK: 2673 { 2674 // map random to 0-999999 without speding much cycles on a modulus operation 2675 uint32_t tk = little_endian_read_32(data,0); 2676 tk = tk & 0xfffff; // 1048575 2677 if (tk >= 999999){ 2678 tk = tk - 999999; 2679 } 2680 sm_reset_tk(); 2681 big_endian_store_32(setup->sm_tk, 12, tk); 2682 if (connection->sm_role){ 2683 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2684 } else { 2685 if (setup->sm_use_secure_connections){ 2686 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 2687 } else { 2688 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2689 sm_trigger_user_response(connection); 2690 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2691 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2692 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 2693 } 2694 } 2695 } 2696 return; 2697 } 2698 case SM_PH2_C1_W4_RANDOM_A: 2699 memcpy(&setup->sm_local_random[0], data, 8); // random endinaness 2700 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_B; 2701 return; 2702 case SM_PH2_C1_W4_RANDOM_B: 2703 memcpy(&setup->sm_local_random[8], data, 8); // random endinaness 2704 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2705 return; 2706 case SM_PH3_W4_RANDOM: 2707 reverse_64(data, setup->sm_local_rand); 2708 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2709 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2710 // no db for authenticated flag hack: store flag in bit 4 of LSB 2711 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2712 connection->sm_engine_state = SM_PH3_GET_DIV; 2713 return; 2714 case SM_PH3_W4_DIV: 2715 // use 16 bit from random value as div 2716 setup->sm_local_div = big_endian_read_16(data, 0); 2717 log_info_hex16("div", setup->sm_local_div); 2718 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2719 return; 2720 default: 2721 break; 2722 } 2723 } 2724 2725 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2726 2727 sm_connection_t * sm_conn; 2728 hci_con_handle_t con_handle; 2729 2730 switch (packet_type) { 2731 2732 case HCI_EVENT_PACKET: 2733 switch (hci_event_packet_get_type(packet)) { 2734 2735 case BTSTACK_EVENT_STATE: 2736 // bt stack activated, get started 2737 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2738 log_info("HCI Working!"); 2739 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 2740 rau_state = RAU_IDLE; 2741 #ifdef USE_MBEDTLS_FOR_ECDH 2742 if (!sm_have_ec_keypair){ 2743 setup->sm_passkey_bit = 0; 2744 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 2745 } 2746 #endif 2747 sm_run(); 2748 } 2749 break; 2750 2751 case HCI_EVENT_LE_META: 2752 switch (packet[2]) { 2753 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2754 2755 log_info("sm: connected"); 2756 2757 if (packet[3]) return; // connection failed 2758 2759 con_handle = little_endian_read_16(packet, 4); 2760 sm_conn = sm_get_connection_for_handle(con_handle); 2761 if (!sm_conn) break; 2762 2763 sm_conn->sm_handle = con_handle; 2764 sm_conn->sm_role = packet[6]; 2765 sm_conn->sm_peer_addr_type = packet[7]; 2766 reverse_bd_addr(&packet[8], 2767 sm_conn->sm_peer_address); 2768 2769 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2770 2771 // reset security properties 2772 sm_conn->sm_connection_encrypted = 0; 2773 sm_conn->sm_connection_authenticated = 0; 2774 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2775 sm_conn->sm_le_db_index = -1; 2776 2777 // prepare CSRK lookup (does not involve setup) 2778 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2779 2780 // just connected -> everything else happens in sm_run() 2781 if (sm_conn->sm_role){ 2782 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2783 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2784 if (sm_slave_request_security) { 2785 // request security if requested by app 2786 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2787 } else { 2788 // otherwise, wait for pairing request 2789 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2790 } 2791 } 2792 break; 2793 } else { 2794 // master 2795 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2796 } 2797 break; 2798 2799 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2800 con_handle = little_endian_read_16(packet, 3); 2801 sm_conn = sm_get_connection_for_handle(con_handle); 2802 if (!sm_conn) break; 2803 2804 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2805 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2806 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2807 break; 2808 } 2809 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 2810 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2811 break; 2812 } 2813 2814 // store rand and ediv 2815 reverse_64(&packet[5], sm_conn->sm_local_rand); 2816 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2817 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK; 2818 break; 2819 2820 default: 2821 break; 2822 } 2823 break; 2824 2825 case HCI_EVENT_ENCRYPTION_CHANGE: 2826 con_handle = little_endian_read_16(packet, 3); 2827 sm_conn = sm_get_connection_for_handle(con_handle); 2828 if (!sm_conn) break; 2829 2830 sm_conn->sm_connection_encrypted = packet[5]; 2831 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 2832 sm_conn->sm_actual_encryption_key_size); 2833 log_info("event handler, state %u", sm_conn->sm_engine_state); 2834 if (!sm_conn->sm_connection_encrypted) break; 2835 // continue if part of initial pairing 2836 switch (sm_conn->sm_engine_state){ 2837 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2838 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2839 sm_done_for_handle(sm_conn->sm_handle); 2840 break; 2841 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2842 if (sm_conn->sm_role){ 2843 // slave 2844 if (setup->sm_use_secure_connections){ 2845 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2846 } else { 2847 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2848 } 2849 } else { 2850 // master 2851 if (sm_key_distribution_all_received(sm_conn)){ 2852 // skip receiving keys as there are none 2853 sm_key_distribution_handle_all_received(sm_conn); 2854 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2855 } else { 2856 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2857 } 2858 } 2859 break; 2860 default: 2861 break; 2862 } 2863 break; 2864 2865 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 2866 con_handle = little_endian_read_16(packet, 3); 2867 sm_conn = sm_get_connection_for_handle(con_handle); 2868 if (!sm_conn) break; 2869 2870 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 2871 log_info("event handler, state %u", sm_conn->sm_engine_state); 2872 // continue if part of initial pairing 2873 switch (sm_conn->sm_engine_state){ 2874 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2875 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2876 sm_done_for_handle(sm_conn->sm_handle); 2877 break; 2878 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2879 if (sm_conn->sm_role){ 2880 // slave 2881 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2882 } else { 2883 // master 2884 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2885 } 2886 break; 2887 default: 2888 break; 2889 } 2890 break; 2891 2892 2893 case HCI_EVENT_DISCONNECTION_COMPLETE: 2894 con_handle = little_endian_read_16(packet, 3); 2895 sm_done_for_handle(con_handle); 2896 sm_conn = sm_get_connection_for_handle(con_handle); 2897 if (!sm_conn) break; 2898 2899 // delete stored bonding on disconnect with authentication failure in ph0 2900 if (sm_conn->sm_role == 0 2901 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 2902 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 2903 le_device_db_remove(sm_conn->sm_le_db_index); 2904 } 2905 2906 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 2907 sm_conn->sm_handle = 0; 2908 break; 2909 2910 case HCI_EVENT_COMMAND_COMPLETE: 2911 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 2912 sm_handle_encryption_result(&packet[6]); 2913 break; 2914 } 2915 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 2916 sm_handle_random_result(&packet[6]); 2917 break; 2918 } 2919 break; 2920 default: 2921 break; 2922 } 2923 break; 2924 default: 2925 break; 2926 } 2927 2928 sm_run(); 2929 } 2930 2931 static inline int sm_calc_actual_encryption_key_size(int other){ 2932 if (other < sm_min_encryption_key_size) return 0; 2933 if (other < sm_max_encryption_key_size) return other; 2934 return sm_max_encryption_key_size; 2935 } 2936 2937 2938 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2939 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 2940 switch (method){ 2941 case JUST_WORKS: 2942 case NK_BOTH_INPUT: 2943 return 1; 2944 default: 2945 return 0; 2946 } 2947 } 2948 // responder 2949 2950 static int sm_passkey_used(stk_generation_method_t method){ 2951 switch (method){ 2952 case PK_RESP_INPUT: 2953 return 1; 2954 default: 2955 return 0; 2956 } 2957 } 2958 #endif 2959 2960 /** 2961 * @return ok 2962 */ 2963 static int sm_validate_stk_generation_method(void){ 2964 // check if STK generation method is acceptable by client 2965 switch (setup->sm_stk_generation_method){ 2966 case JUST_WORKS: 2967 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 2968 case PK_RESP_INPUT: 2969 case PK_INIT_INPUT: 2970 case OK_BOTH_INPUT: 2971 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 2972 case OOB: 2973 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 2974 case NK_BOTH_INPUT: 2975 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 2976 return 1; 2977 default: 2978 return 0; 2979 } 2980 } 2981 2982 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 2983 2984 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 2985 sm_run(); 2986 } 2987 2988 if (packet_type != SM_DATA_PACKET) return; 2989 2990 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 2991 if (!sm_conn) return; 2992 2993 if (packet[0] == SM_CODE_PAIRING_FAILED){ 2994 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2995 return; 2996 } 2997 2998 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, packet[0]); 2999 3000 int err; 3001 3002 if (packet[0] == SM_CODE_KEYPRESS_NOTIFICATION){ 3003 uint8_t buffer[5]; 3004 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3005 buffer[1] = 3; 3006 little_endian_store_16(buffer, 2, con_handle); 3007 buffer[4] = packet[1]; 3008 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3009 return; 3010 } 3011 3012 switch (sm_conn->sm_engine_state){ 3013 3014 // a sm timeout requries a new physical connection 3015 case SM_GENERAL_TIMEOUT: 3016 return; 3017 3018 // Initiator 3019 case SM_INITIATOR_CONNECTED: 3020 if ((packet[0] != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3021 sm_pdu_received_in_wrong_state(sm_conn); 3022 break; 3023 } 3024 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 3025 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3026 break; 3027 } 3028 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 3029 uint16_t ediv; 3030 sm_key_t ltk; 3031 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3032 if (!sm_is_null_key(ltk) || ediv){ 3033 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3034 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3035 } else { 3036 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3037 } 3038 break; 3039 } 3040 // otherwise, store security request 3041 sm_conn->sm_security_request_received = 1; 3042 break; 3043 3044 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3045 if (packet[0] != SM_CODE_PAIRING_RESPONSE){ 3046 sm_pdu_received_in_wrong_state(sm_conn); 3047 break; 3048 } 3049 // store pairing request 3050 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3051 err = sm_stk_generation_init(sm_conn); 3052 if (err){ 3053 setup->sm_pairing_failed_reason = err; 3054 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3055 break; 3056 } 3057 3058 // generate random number first, if we need to show passkey 3059 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3060 sm_conn->sm_engine_state = SM_PH2_GET_RANDOM_TK; 3061 break; 3062 } 3063 3064 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3065 if (setup->sm_use_secure_connections){ 3066 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3067 if (setup->sm_stk_generation_method == JUST_WORKS){ 3068 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3069 sm_trigger_user_response(sm_conn); 3070 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3071 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3072 } 3073 } else { 3074 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3075 } 3076 break; 3077 } 3078 #endif 3079 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3080 sm_trigger_user_response(sm_conn); 3081 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3082 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3083 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3084 } 3085 break; 3086 3087 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3088 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3089 sm_pdu_received_in_wrong_state(sm_conn); 3090 break; 3091 } 3092 3093 // store s_confirm 3094 reverse_128(&packet[1], setup->sm_peer_confirm); 3095 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3096 break; 3097 3098 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3099 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3100 sm_pdu_received_in_wrong_state(sm_conn); 3101 break;; 3102 } 3103 3104 // received random value 3105 reverse_128(&packet[1], setup->sm_peer_random); 3106 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3107 break; 3108 3109 // Responder 3110 case SM_RESPONDER_IDLE: 3111 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3112 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3113 if (packet[0] != SM_CODE_PAIRING_REQUEST){ 3114 sm_pdu_received_in_wrong_state(sm_conn); 3115 break;; 3116 } 3117 3118 // store pairing request 3119 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3120 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3121 break; 3122 3123 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3124 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3125 if (packet[0] != SM_CODE_PAIRING_PUBLIC_KEY){ 3126 sm_pdu_received_in_wrong_state(sm_conn); 3127 break; 3128 } 3129 3130 // store public key for DH Key calculation 3131 reverse_256(&packet[01], setup->sm_peer_qx); 3132 reverse_256(&packet[33], setup->sm_peer_qy); 3133 3134 #ifdef USE_MBEDTLS_FOR_ECDH 3135 // validate public key 3136 mbedtls_ecp_point Q; 3137 mbedtls_ecp_point_init( &Q ); 3138 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 3139 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 3140 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 3141 err = mbedtls_ecp_check_pubkey(&mbedtls_ec_group, &Q); 3142 mbedtls_ecp_point_free( & Q); 3143 if (err){ 3144 log_error("sm: peer public key invalid %x", err); 3145 // uses "unspecified reason", there is no "public key invalid" error code 3146 sm_pdu_received_in_wrong_state(sm_conn); 3147 break; 3148 } 3149 3150 #endif 3151 if (sm_conn->sm_role){ 3152 // responder 3153 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3154 } else { 3155 // initiator 3156 // stk generation method 3157 // passkey entry: notify app to show passkey or to request passkey 3158 switch (setup->sm_stk_generation_method){ 3159 case JUST_WORKS: 3160 case NK_BOTH_INPUT: 3161 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3162 break; 3163 case PK_RESP_INPUT: 3164 sm_sc_start_calculating_local_confirm(sm_conn); 3165 break; 3166 case PK_INIT_INPUT: 3167 case OK_BOTH_INPUT: 3168 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3169 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3170 break; 3171 } 3172 sm_sc_start_calculating_local_confirm(sm_conn); 3173 break; 3174 case OOB: 3175 // TODO: implement SC OOB 3176 break; 3177 } 3178 } 3179 break; 3180 3181 case SM_SC_W4_CONFIRMATION: 3182 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3183 sm_pdu_received_in_wrong_state(sm_conn); 3184 break; 3185 } 3186 // received confirm value 3187 reverse_128(&packet[1], setup->sm_peer_confirm); 3188 3189 if (sm_conn->sm_role){ 3190 // responder 3191 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3192 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3193 // still waiting for passkey 3194 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3195 break; 3196 } 3197 } 3198 sm_sc_start_calculating_local_confirm(sm_conn); 3199 } else { 3200 // initiator 3201 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3202 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3203 } else { 3204 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3205 } 3206 } 3207 break; 3208 3209 case SM_SC_W4_PAIRING_RANDOM: 3210 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3211 sm_pdu_received_in_wrong_state(sm_conn); 3212 break; 3213 } 3214 3215 // received random value 3216 reverse_128(&packet[1], setup->sm_peer_nonce); 3217 3218 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3219 // only check for JUST WORK/NC in initiator role AND passkey entry 3220 if (sm_conn->sm_role || sm_passkey_used(setup->sm_stk_generation_method)) { 3221 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3222 } 3223 3224 sm_sc_state_after_receiving_random(sm_conn); 3225 break; 3226 3227 case SM_SC_W2_CALCULATE_G2: 3228 case SM_SC_W4_CALCULATE_G2: 3229 case SM_SC_W2_CALCULATE_F5_SALT: 3230 case SM_SC_W4_CALCULATE_F5_SALT: 3231 case SM_SC_W2_CALCULATE_F5_MACKEY: 3232 case SM_SC_W4_CALCULATE_F5_MACKEY: 3233 case SM_SC_W2_CALCULATE_F5_LTK: 3234 case SM_SC_W4_CALCULATE_F5_LTK: 3235 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3236 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3237 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3238 if (packet[0] != SM_CODE_PAIRING_DHKEY_CHECK){ 3239 sm_pdu_received_in_wrong_state(sm_conn); 3240 break; 3241 } 3242 // store DHKey Check 3243 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3244 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3245 3246 // have we been only waiting for dhkey check command? 3247 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3248 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3249 } 3250 break; 3251 #endif 3252 3253 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3254 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3255 sm_pdu_received_in_wrong_state(sm_conn); 3256 break; 3257 } 3258 3259 // received confirm value 3260 reverse_128(&packet[1], setup->sm_peer_confirm); 3261 3262 // notify client to hide shown passkey 3263 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3264 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3265 } 3266 3267 // handle user cancel pairing? 3268 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3269 setup->sm_pairing_failed_reason = SM_REASON_PASSKEYT_ENTRY_FAILED; 3270 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3271 break; 3272 } 3273 3274 // wait for user action? 3275 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3276 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3277 break; 3278 } 3279 3280 // calculate and send local_confirm 3281 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3282 break; 3283 3284 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3285 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3286 sm_pdu_received_in_wrong_state(sm_conn); 3287 break;; 3288 } 3289 3290 // received random value 3291 reverse_128(&packet[1], setup->sm_peer_random); 3292 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3293 break; 3294 3295 case SM_PH3_RECEIVE_KEYS: 3296 switch(packet[0]){ 3297 case SM_CODE_ENCRYPTION_INFORMATION: 3298 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3299 reverse_128(&packet[1], setup->sm_peer_ltk); 3300 break; 3301 3302 case SM_CODE_MASTER_IDENTIFICATION: 3303 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3304 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3305 reverse_64(&packet[3], setup->sm_peer_rand); 3306 break; 3307 3308 case SM_CODE_IDENTITY_INFORMATION: 3309 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3310 reverse_128(&packet[1], setup->sm_peer_irk); 3311 break; 3312 3313 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3314 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3315 setup->sm_peer_addr_type = packet[1]; 3316 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3317 break; 3318 3319 case SM_CODE_SIGNING_INFORMATION: 3320 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3321 reverse_128(&packet[1], setup->sm_peer_csrk); 3322 break; 3323 default: 3324 // Unexpected PDU 3325 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3326 break; 3327 } 3328 // done with key distribution? 3329 if (sm_key_distribution_all_received(sm_conn)){ 3330 3331 sm_key_distribution_handle_all_received(sm_conn); 3332 3333 if (sm_conn->sm_role){ 3334 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3335 sm_done_for_handle(sm_conn->sm_handle); 3336 } else { 3337 if (setup->sm_use_secure_connections){ 3338 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3339 } else { 3340 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3341 } 3342 } 3343 } 3344 break; 3345 default: 3346 // Unexpected PDU 3347 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3348 break; 3349 } 3350 3351 // try to send preparared packet 3352 sm_run(); 3353 } 3354 3355 // Security Manager Client API 3356 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data)){ 3357 sm_get_oob_data = get_oob_data_callback; 3358 } 3359 3360 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3361 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3362 } 3363 3364 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3365 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3366 } 3367 3368 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3369 sm_min_encryption_key_size = min_size; 3370 sm_max_encryption_key_size = max_size; 3371 } 3372 3373 void sm_set_authentication_requirements(uint8_t auth_req){ 3374 sm_auth_req = auth_req; 3375 } 3376 3377 void sm_set_io_capabilities(io_capability_t io_capability){ 3378 sm_io_capabilities = io_capability; 3379 } 3380 3381 void sm_set_request_security(int enable){ 3382 sm_slave_request_security = enable; 3383 } 3384 3385 void sm_set_er(sm_key_t er){ 3386 memcpy(sm_persistent_er, er, 16); 3387 } 3388 3389 void sm_set_ir(sm_key_t ir){ 3390 memcpy(sm_persistent_ir, ir, 16); 3391 } 3392 3393 // Testing support only 3394 void sm_test_set_irk(sm_key_t irk){ 3395 memcpy(sm_persistent_irk, irk, 16); 3396 sm_persistent_irk_ready = 1; 3397 } 3398 3399 void sm_test_use_fixed_local_csrk(void){ 3400 test_use_fixed_local_csrk = 1; 3401 } 3402 3403 void sm_init(void){ 3404 // set some (BTstack default) ER and IR 3405 int i; 3406 sm_key_t er; 3407 sm_key_t ir; 3408 for (i=0;i<16;i++){ 3409 er[i] = 0x30 + i; 3410 ir[i] = 0x90 + i; 3411 } 3412 sm_set_er(er); 3413 sm_set_ir(ir); 3414 // defaults 3415 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3416 | SM_STK_GENERATION_METHOD_OOB 3417 | SM_STK_GENERATION_METHOD_PASSKEY 3418 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3419 3420 sm_max_encryption_key_size = 16; 3421 sm_min_encryption_key_size = 7; 3422 3423 sm_cmac_state = CMAC_IDLE; 3424 dkg_state = DKG_W4_WORKING; 3425 rau_state = RAU_W4_WORKING; 3426 sm_aes128_state = SM_AES128_IDLE; 3427 sm_address_resolution_test = -1; // no private address to resolve yet 3428 sm_address_resolution_ah_calculation_active = 0; 3429 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3430 sm_address_resolution_general_queue = NULL; 3431 3432 gap_random_adress_update_period = 15 * 60 * 1000L; 3433 3434 sm_active_connection = 0; 3435 3436 test_use_fixed_local_csrk = 0; 3437 3438 // register for HCI Events from HCI 3439 hci_event_callback_registration.callback = &sm_event_packet_handler; 3440 hci_add_event_handler(&hci_event_callback_registration); 3441 3442 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3443 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3444 3445 #ifdef USE_MBEDTLS_FOR_ECDH 3446 ec_key_generation_state = EC_KEY_GENERATION_IDLE; 3447 3448 #ifndef HAVE_MALLOC 3449 sm_mbedtls_allocator_init(mbedtls_memory_buffer, sizeof(mbedtls_memory_buffer)); 3450 #endif 3451 mbedtls_ecp_group_init(&mbedtls_ec_group); 3452 mbedtls_ecp_group_load(&mbedtls_ec_group, MBEDTLS_ECP_DP_SECP256R1); 3453 3454 #if 0 3455 // test 3456 sm_test_use_fixed_ec_keypair(); 3457 if (sm_have_ec_keypair){ 3458 printf("test dhkey check\n"); 3459 sm_key256_t dhkey; 3460 memcpy(setup->sm_peer_qx, ec_qx, 32); 3461 memcpy(setup->sm_peer_qy, ec_qy, 32); 3462 sm_sc_calculate_dhkey(dhkey); 3463 } 3464 #endif 3465 #endif 3466 } 3467 3468 void sm_use_fixed_ec_keypair(uint8_t * qx, uint8_t * qy, uint8_t * d){ 3469 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3470 memcpy(ec_qx, qx, 32); 3471 memcpy(ec_qy, qy, 32); 3472 memcpy(ec_d, d, 32); 3473 sm_have_ec_keypair = 1; 3474 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3475 #endif 3476 } 3477 3478 void sm_test_use_fixed_ec_keypair(void){ 3479 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3480 #ifdef USE_MBEDTLS_FOR_ECDH 3481 // use test keypair from spec 3482 mbedtls_mpi x; 3483 mbedtls_mpi_init(&x); 3484 mbedtls_mpi_read_string( &x, 16, "3f49f6d4a3c55f3874c9b3e3d2103f504aff607beb40b7995899b8a6cd3c1abd"); 3485 mbedtls_mpi_write_binary(&x, ec_d, 32); 3486 mbedtls_mpi_read_string( &x, 16, "20b003d2f297be2c5e2c83a7e9f9a5b9eff49111acf4fddbcc0301480e359de6"); 3487 mbedtls_mpi_write_binary(&x, ec_qx, 32); 3488 mbedtls_mpi_read_string( &x, 16, "dc809c49652aeb6d63329abf5a52155c766345c28fed3024741c8ed01589d28b"); 3489 mbedtls_mpi_write_binary(&x, ec_qy, 32); 3490 mbedtls_mpi_free(&x); 3491 #endif 3492 sm_have_ec_keypair = 1; 3493 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3494 #endif 3495 } 3496 3497 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3498 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3499 if (!hci_con) return NULL; 3500 return &hci_con->sm_connection; 3501 } 3502 3503 // @returns 0 if not encrypted, 7-16 otherwise 3504 int sm_encryption_key_size(hci_con_handle_t con_handle){ 3505 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3506 if (!sm_conn) return 0; // wrong connection 3507 if (!sm_conn->sm_connection_encrypted) return 0; 3508 return sm_conn->sm_actual_encryption_key_size; 3509 } 3510 3511 int sm_authenticated(hci_con_handle_t con_handle){ 3512 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3513 if (!sm_conn) return 0; // wrong connection 3514 if (!sm_conn->sm_connection_encrypted) return 0; // unencrypted connection cannot be authenticated 3515 return sm_conn->sm_connection_authenticated; 3516 } 3517 3518 authorization_state_t sm_authorization_state(hci_con_handle_t con_handle){ 3519 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3520 if (!sm_conn) return AUTHORIZATION_UNKNOWN; // wrong connection 3521 if (!sm_conn->sm_connection_encrypted) return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized 3522 if (!sm_conn->sm_connection_authenticated) return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized 3523 return sm_conn->sm_connection_authorization_state; 3524 } 3525 3526 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3527 switch (sm_conn->sm_engine_state){ 3528 case SM_GENERAL_IDLE: 3529 case SM_RESPONDER_IDLE: 3530 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3531 sm_run(); 3532 break; 3533 default: 3534 break; 3535 } 3536 } 3537 3538 /** 3539 * @brief Trigger Security Request 3540 */ 3541 void sm_send_security_request(hci_con_handle_t con_handle){ 3542 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3543 if (!sm_conn) return; 3544 sm_send_security_request_for_connection(sm_conn); 3545 } 3546 3547 // request pairing 3548 void sm_request_pairing(hci_con_handle_t con_handle){ 3549 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3550 if (!sm_conn) return; // wrong connection 3551 3552 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3553 if (sm_conn->sm_role){ 3554 sm_send_security_request_for_connection(sm_conn); 3555 } else { 3556 // used as a trigger to start central/master/initiator security procedures 3557 uint16_t ediv; 3558 sm_key_t ltk; 3559 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3560 switch (sm_conn->sm_irk_lookup_state){ 3561 case IRK_LOOKUP_FAILED: 3562 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3563 break; 3564 case IRK_LOOKUP_SUCCEEDED: 3565 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3566 if (!sm_is_null_key(ltk) || ediv){ 3567 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3568 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3569 } else { 3570 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3571 } 3572 break; 3573 default: 3574 sm_conn->sm_bonding_requested = 1; 3575 break; 3576 } 3577 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3578 sm_conn->sm_bonding_requested = 1; 3579 } 3580 } 3581 sm_run(); 3582 } 3583 3584 // called by client app on authorization request 3585 void sm_authorization_decline(hci_con_handle_t con_handle){ 3586 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3587 if (!sm_conn) return; // wrong connection 3588 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3589 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3590 } 3591 3592 void sm_authorization_grant(hci_con_handle_t con_handle){ 3593 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3594 if (!sm_conn) return; // wrong connection 3595 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3596 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3597 } 3598 3599 // GAP Bonding API 3600 3601 void sm_bonding_decline(hci_con_handle_t con_handle){ 3602 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3603 if (!sm_conn) return; // wrong connection 3604 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3605 3606 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3607 switch (setup->sm_stk_generation_method){ 3608 case PK_RESP_INPUT: 3609 case PK_INIT_INPUT: 3610 case OK_BOTH_INPUT: 3611 sm_pairing_error(sm_conn, SM_GENERAL_SEND_PAIRING_FAILED); 3612 break; 3613 case NK_BOTH_INPUT: 3614 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 3615 break; 3616 case JUST_WORKS: 3617 case OOB: 3618 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 3619 break; 3620 } 3621 } 3622 sm_run(); 3623 } 3624 3625 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3626 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3627 if (!sm_conn) return; // wrong connection 3628 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3629 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3630 if (setup->sm_use_secure_connections){ 3631 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3632 } else { 3633 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3634 } 3635 } 3636 3637 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3638 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3639 sm_sc_prepare_dhkey_check(sm_conn); 3640 } 3641 #endif 3642 3643 sm_run(); 3644 } 3645 3646 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3647 // for now, it's the same 3648 sm_just_works_confirm(con_handle); 3649 } 3650 3651 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3652 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3653 if (!sm_conn) return; // wrong connection 3654 sm_reset_tk(); 3655 big_endian_store_32(setup->sm_tk, 12, passkey); 3656 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3657 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3658 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3659 } 3660 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3661 memcpy(setup->sm_ra, setup->sm_tk, 16); 3662 memcpy(setup->sm_rb, setup->sm_tk, 16); 3663 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3664 sm_sc_start_calculating_local_confirm(sm_conn); 3665 } 3666 #endif 3667 sm_run(); 3668 } 3669 3670 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 3671 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3672 if (!sm_conn) return; // wrong connection 3673 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 3674 setup->sm_keypress_notification = action; 3675 sm_run(); 3676 } 3677 3678 /** 3679 * @brief Identify device in LE Device DB 3680 * @param handle 3681 * @returns index from le_device_db or -1 if not found/identified 3682 */ 3683 int sm_le_device_index(hci_con_handle_t con_handle ){ 3684 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3685 if (!sm_conn) return -1; 3686 return sm_conn->sm_le_db_index; 3687 } 3688 3689 // GAP LE API 3690 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 3691 gap_random_address_update_stop(); 3692 gap_random_adress_type = random_address_type; 3693 if (random_address_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3694 gap_random_address_update_start(); 3695 gap_random_address_trigger(); 3696 } 3697 3698 gap_random_address_type_t gap_random_address_get_mode(void){ 3699 return gap_random_adress_type; 3700 } 3701 3702 void gap_random_address_set_update_period(int period_ms){ 3703 gap_random_adress_update_period = period_ms; 3704 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3705 gap_random_address_update_stop(); 3706 gap_random_address_update_start(); 3707 } 3708 3709 void gap_random_address_set(bd_addr_t addr){ 3710 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_OFF); 3711 memcpy(sm_random_address, addr, 6); 3712 rau_state = RAU_SET_ADDRESS; 3713 sm_run(); 3714 } 3715 3716 /* 3717 * @brief Set Advertisement Paramters 3718 * @param adv_int_min 3719 * @param adv_int_max 3720 * @param adv_type 3721 * @param direct_address_type 3722 * @param direct_address 3723 * @param channel_map 3724 * @param filter_policy 3725 * 3726 * @note own_address_type is used from gap_random_address_set_mode 3727 */ 3728 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 3729 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 3730 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, gap_random_adress_type, 3731 direct_address_typ, direct_address, channel_map, filter_policy); 3732 } 3733 3734