1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 #include <stdio.h> 39 #include <string.h> 40 #include <inttypes.h> 41 42 #include "ble/le_device_db.h" 43 #include "ble/core.h" 44 #include "ble/sm.h" 45 #include "btstack_debug.h" 46 #include "btstack_event.h" 47 #include "btstack_linked_list.h" 48 #include "btstack_memory.h" 49 #include "gap.h" 50 #include "hci.h" 51 #include "l2cap.h" 52 53 #ifdef ENABLE_LE_SECURE_CONNECTIONS 54 #ifdef HAVE_HCI_CONTROLLER_DHKEY_SUPPORT 55 #error "Support for DHKEY Support in HCI Controller not implemented yet. Please use software implementation" 56 #else 57 #define USE_MBEDTLS_FOR_ECDH 58 #endif 59 #endif 60 61 62 // Software ECDH implementation provided by mbedtls 63 #ifdef USE_MBEDTLS_FOR_ECDH 64 #include "mbedtls/config.h" 65 #include "mbedtls/platform.h" 66 #include "mbedtls/ecp.h" 67 #include "sm_mbedtls_allocator.h" 68 #endif 69 70 // 71 // SM internal types and globals 72 // 73 74 typedef enum { 75 DKG_W4_WORKING, 76 DKG_CALC_IRK, 77 DKG_W4_IRK, 78 DKG_CALC_DHK, 79 DKG_W4_DHK, 80 DKG_READY 81 } derived_key_generation_t; 82 83 typedef enum { 84 RAU_W4_WORKING, 85 RAU_IDLE, 86 RAU_GET_RANDOM, 87 RAU_W4_RANDOM, 88 RAU_GET_ENC, 89 RAU_W4_ENC, 90 RAU_SET_ADDRESS, 91 } random_address_update_t; 92 93 typedef enum { 94 CMAC_IDLE, 95 CMAC_CALC_SUBKEYS, 96 CMAC_W4_SUBKEYS, 97 CMAC_CALC_MI, 98 CMAC_W4_MI, 99 CMAC_CALC_MLAST, 100 CMAC_W4_MLAST 101 } cmac_state_t; 102 103 typedef enum { 104 JUST_WORKS, 105 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 106 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 107 OK_BOTH_INPUT, // Only input on both, both input PK 108 NK_BOTH_INPUT, // Only numerical compparison (yes/no) on on both sides 109 OOB // OOB available on both sides 110 } stk_generation_method_t; 111 112 typedef enum { 113 SM_USER_RESPONSE_IDLE, 114 SM_USER_RESPONSE_PENDING, 115 SM_USER_RESPONSE_CONFIRM, 116 SM_USER_RESPONSE_PASSKEY, 117 SM_USER_RESPONSE_DECLINE 118 } sm_user_response_t; 119 120 typedef enum { 121 SM_AES128_IDLE, 122 SM_AES128_ACTIVE 123 } sm_aes128_state_t; 124 125 typedef enum { 126 ADDRESS_RESOLUTION_IDLE, 127 ADDRESS_RESOLUTION_GENERAL, 128 ADDRESS_RESOLUTION_FOR_CONNECTION, 129 } address_resolution_mode_t; 130 131 typedef enum { 132 ADDRESS_RESOLUTION_SUCEEDED, 133 ADDRESS_RESOLUTION_FAILED, 134 } address_resolution_event_t; 135 136 typedef enum { 137 EC_KEY_GENERATION_IDLE, 138 EC_KEY_GENERATION_ACTIVE, 139 EC_KEY_GENERATION_DONE, 140 } ec_key_generation_state_t; 141 142 typedef enum { 143 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 0 144 } sm_state_var_t; 145 146 // 147 // GLOBAL DATA 148 // 149 150 static uint8_t test_use_fixed_local_csrk; 151 152 // configuration 153 static uint8_t sm_accepted_stk_generation_methods; 154 static uint8_t sm_max_encryption_key_size; 155 static uint8_t sm_min_encryption_key_size; 156 static uint8_t sm_auth_req = 0; 157 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 158 static uint8_t sm_slave_request_security; 159 static uint8_t sm_have_ec_keypair; 160 161 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 162 static sm_key_t sm_persistent_er; 163 static sm_key_t sm_persistent_ir; 164 165 // derived from sm_persistent_ir 166 static sm_key_t sm_persistent_dhk; 167 static sm_key_t sm_persistent_irk; 168 static uint8_t sm_persistent_irk_ready = 0; // used for testing 169 static derived_key_generation_t dkg_state; 170 171 // derived from sm_persistent_er 172 // .. 173 174 // random address update 175 static random_address_update_t rau_state; 176 static bd_addr_t sm_random_address; 177 178 // CMAC Calculation: General 179 static cmac_state_t sm_cmac_state; 180 static uint16_t sm_cmac_message_len; 181 static sm_key_t sm_cmac_k; 182 static sm_key_t sm_cmac_x; 183 static sm_key_t sm_cmac_m_last; 184 static uint8_t sm_cmac_block_current; 185 static uint8_t sm_cmac_block_count; 186 static uint8_t (*sm_cmac_get_byte)(uint16_t offset); 187 static void (*sm_cmac_done_handler)(uint8_t * hash); 188 189 // CMAC for ATT Signed Writes 190 static uint8_t sm_cmac_header[3]; 191 static const uint8_t * sm_cmac_message; 192 static uint8_t sm_cmac_sign_counter[4]; 193 194 // CMAC for Secure Connection functions 195 #ifdef ENABLE_LE_SECURE_CONNECTIONS 196 static sm_connection_t * sm_cmac_connection; 197 static uint8_t sm_cmac_sc_buffer[80]; 198 #endif 199 200 // resolvable private address lookup / CSRK calculation 201 static int sm_address_resolution_test; 202 static int sm_address_resolution_ah_calculation_active; 203 static uint8_t sm_address_resolution_addr_type; 204 static bd_addr_t sm_address_resolution_address; 205 static void * sm_address_resolution_context; 206 static address_resolution_mode_t sm_address_resolution_mode; 207 static btstack_linked_list_t sm_address_resolution_general_queue; 208 209 // aes128 crypto engine. store current sm_connection_t in sm_aes128_context 210 static sm_aes128_state_t sm_aes128_state; 211 static void * sm_aes128_context; 212 213 // random engine. store context (ususally sm_connection_t) 214 static void * sm_random_context; 215 216 // to receive hci events 217 static btstack_packet_callback_registration_t hci_event_callback_registration; 218 219 /* to dispatch sm event */ 220 static btstack_linked_list_t sm_event_handlers; 221 222 223 // Software ECDH implementation provided by mbedtls 224 #ifdef USE_MBEDTLS_FOR_ECDH 225 // group is always valid 226 static mbedtls_ecp_group mbedtls_ec_group; 227 static ec_key_generation_state_t ec_key_generation_state; 228 static uint8_t ec_qx[32]; 229 static uint8_t ec_qy[32]; 230 static uint8_t ec_d[32]; 231 #ifndef HAVE_MALLOC 232 // 4304 bytes with 73 allocations 233 #define MBEDTLS_ALLOC_BUFFER_SIZE (1300+23*sizeof(void *)) 234 static uint8_t mbedtls_memory_buffer[MBEDTLS_ALLOC_BUFFER_SIZE]; 235 #endif 236 #endif 237 238 // 239 // Volume 3, Part H, Chapter 24 240 // "Security shall be initiated by the Security Manager in the device in the master role. 241 // The device in the slave role shall be the responding device." 242 // -> master := initiator, slave := responder 243 // 244 245 // data needed for security setup 246 typedef struct sm_setup_context { 247 248 btstack_timer_source_t sm_timeout; 249 250 // used in all phases 251 uint8_t sm_pairing_failed_reason; 252 253 // user response, (Phase 1 and/or 2) 254 uint8_t sm_user_response; 255 256 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 257 int sm_key_distribution_send_set; 258 int sm_key_distribution_received_set; 259 260 // Phase 2 (Pairing over SMP) 261 stk_generation_method_t sm_stk_generation_method; 262 sm_key_t sm_tk; 263 uint8_t sm_use_secure_connections; 264 265 sm_key_t sm_c1_t3_value; // c1 calculation 266 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 267 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 268 sm_key_t sm_local_random; 269 sm_key_t sm_local_confirm; 270 sm_key_t sm_peer_random; 271 sm_key_t sm_peer_confirm; 272 uint8_t sm_m_addr_type; // address and type can be removed 273 uint8_t sm_s_addr_type; // '' 274 bd_addr_t sm_m_address; // '' 275 bd_addr_t sm_s_address; // '' 276 sm_key_t sm_ltk; 277 278 uint8_t sm_state_vars; 279 #ifdef ENABLE_LE_SECURE_CONNECTIONS 280 uint8_t sm_peer_qx[32]; // also stores random for EC key generation during init 281 uint8_t sm_peer_qy[32]; // '' 282 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 283 sm_key_t sm_local_nonce; // might be combined with sm_local_random 284 sm_key_t sm_peer_dhkey_check; 285 sm_key_t sm_local_dhkey_check; 286 sm_key_t sm_ra; 287 sm_key_t sm_rb; 288 sm_key_t sm_t; // used for f5 289 sm_key_t sm_mackey; 290 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 291 #endif 292 293 // Phase 3 294 295 // key distribution, we generate 296 uint16_t sm_local_y; 297 uint16_t sm_local_div; 298 uint16_t sm_local_ediv; 299 uint8_t sm_local_rand[8]; 300 sm_key_t sm_local_ltk; 301 sm_key_t sm_local_csrk; 302 sm_key_t sm_local_irk; 303 // sm_local_address/addr_type not needed 304 305 // key distribution, received from peer 306 uint16_t sm_peer_y; 307 uint16_t sm_peer_div; 308 uint16_t sm_peer_ediv; 309 uint8_t sm_peer_rand[8]; 310 sm_key_t sm_peer_ltk; 311 sm_key_t sm_peer_irk; 312 sm_key_t sm_peer_csrk; 313 uint8_t sm_peer_addr_type; 314 bd_addr_t sm_peer_address; 315 316 } sm_setup_context_t; 317 318 // 319 static sm_setup_context_t the_setup; 320 static sm_setup_context_t * setup = &the_setup; 321 322 // active connection - the one for which the_setup is used for 323 static uint16_t sm_active_connection = 0; 324 325 // @returns 1 if oob data is available 326 // stores oob data in provided 16 byte buffer if not null 327 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 328 329 // used to notify applicationss that user interaction is neccessary, see sm_notify_t below 330 static btstack_packet_handler_t sm_client_packet_handler = 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 if (sm_client_packet_handler) { 677 sm_client_packet_handler(HCI_EVENT_PACKET, 0, packet, size); 678 } 679 // dispatch to all event handlers 680 btstack_linked_list_iterator_t it; 681 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 682 while (btstack_linked_list_iterator_has_next(&it)){ 683 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 684 entry->callback(packet_type, 0, packet, size); 685 } 686 } 687 688 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 689 uint8_t event[11]; 690 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 691 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 692 } 693 694 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){ 695 uint8_t event[15]; 696 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 697 little_endian_store_32(event, 11, passkey); 698 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 699 } 700 701 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){ 702 uint8_t event[13]; 703 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 704 little_endian_store_16(event, 11, index); 705 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 706 } 707 708 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){ 709 710 uint8_t event[18]; 711 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 712 event[11] = result; 713 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 714 } 715 716 // decide on stk generation based on 717 // - pairing request 718 // - io capabilities 719 // - OOB data availability 720 static void sm_setup_tk(void){ 721 722 // default: just works 723 setup->sm_stk_generation_method = JUST_WORKS; 724 725 #ifdef ENABLE_LE_SECURE_CONNECTIONS 726 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 727 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 728 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 729 memset(setup->sm_ra, 0, 16); 730 memset(setup->sm_rb, 0, 16); 731 #else 732 setup->sm_use_secure_connections = 0; 733 #endif 734 735 // If both devices have not set the MITM option in the Authentication Requirements 736 // Flags, then the IO capabilities shall be ignored and the Just Works association 737 // model shall be used. 738 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 739 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 740 log_info("SM: MITM not required by both -> JUST WORKS"); 741 return; 742 } 743 744 // TODO: with LE SC, OOB is used to transfer data OOB during pairing, single device with OOB is sufficient 745 746 // If both devices have out of band authentication data, then the Authentication 747 // Requirements Flags shall be ignored when selecting the pairing method and the 748 // Out of Band pairing method shall be used. 749 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) 750 && sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)){ 751 log_info("SM: have OOB data"); 752 log_info_key("OOB", setup->sm_tk); 753 setup->sm_stk_generation_method = OOB; 754 return; 755 } 756 757 // Reset TK as it has been setup in sm_init_setup 758 sm_reset_tk(); 759 760 // Also use just works if unknown io capabilites 761 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)){ 762 return; 763 } 764 765 // Otherwise the IO capabilities of the devices shall be used to determine the 766 // pairing method as defined in Table 2.4. 767 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 768 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 769 770 #ifdef ENABLE_LE_SECURE_CONNECTIONS 771 // table not define by default 772 if (setup->sm_use_secure_connections){ 773 generation_method = stk_generation_method_with_secure_connection; 774 } 775 #endif 776 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)]; 777 778 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 779 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); 780 } 781 782 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 783 int flags = 0; 784 if (key_set & SM_KEYDIST_ENC_KEY){ 785 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 786 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 787 } 788 if (key_set & SM_KEYDIST_ID_KEY){ 789 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 790 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 791 } 792 if (key_set & SM_KEYDIST_SIGN){ 793 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 794 } 795 return flags; 796 } 797 798 static void sm_setup_key_distribution(uint8_t key_set){ 799 setup->sm_key_distribution_received_set = 0; 800 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 801 } 802 803 // CSRK Key Lookup 804 805 806 static int sm_address_resolution_idle(void){ 807 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 808 } 809 810 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){ 811 memcpy(sm_address_resolution_address, addr, 6); 812 sm_address_resolution_addr_type = addr_type; 813 sm_address_resolution_test = 0; 814 sm_address_resolution_mode = mode; 815 sm_address_resolution_context = context; 816 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 817 } 818 819 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 820 // check if already in list 821 btstack_linked_list_iterator_t it; 822 sm_lookup_entry_t * entry; 823 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 824 while(btstack_linked_list_iterator_has_next(&it)){ 825 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 826 if (entry->address_type != address_type) continue; 827 if (memcmp(entry->address, address, 6)) continue; 828 // already in list 829 return BTSTACK_BUSY; 830 } 831 entry = btstack_memory_sm_lookup_entry_get(); 832 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 833 entry->address_type = (bd_addr_type_t) address_type; 834 memcpy(entry->address, address, 6); 835 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 836 sm_run(); 837 return 0; 838 } 839 840 // CMAC Implementation using AES128 engine 841 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 842 int i; 843 int carry = 0; 844 for (i=len-1; i >= 0 ; i--){ 845 int new_carry = data[i] >> 7; 846 data[i] = data[i] << 1 | carry; 847 carry = new_carry; 848 } 849 } 850 851 // 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 852 static inline void sm_next_responding_state(sm_connection_t * sm_conn){ 853 sm_conn->sm_engine_state = (security_manager_state_t) (((int)sm_conn->sm_engine_state) + 1); 854 } 855 static inline void dkg_next_state(void){ 856 dkg_state = (derived_key_generation_t) (((int)dkg_state) + 1); 857 } 858 static inline void rau_next_state(void){ 859 rau_state = (random_address_update_t) (((int)rau_state) + 1); 860 } 861 862 // CMAC calculation using AES Engine 863 864 static inline void sm_cmac_next_state(void){ 865 sm_cmac_state = (cmac_state_t) (((int)sm_cmac_state) + 1); 866 } 867 868 static int sm_cmac_last_block_complete(void){ 869 if (sm_cmac_message_len == 0) return 0; 870 return (sm_cmac_message_len & 0x0f) == 0; 871 } 872 873 static inline uint8_t sm_cmac_message_get_byte(uint16_t offset){ 874 if (offset >= sm_cmac_message_len) { 875 log_error("sm_cmac_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_message_len); 876 return 0; 877 } 878 879 offset = sm_cmac_message_len - 1 - offset; 880 881 // sm_cmac_header[3] | message[] | sm_cmac_sign_counter[4] 882 if (offset < 3){ 883 return sm_cmac_header[offset]; 884 } 885 int actual_message_len_incl_header = sm_cmac_message_len - 4; 886 if (offset < actual_message_len_incl_header){ 887 return sm_cmac_message[offset - 3]; 888 } 889 return sm_cmac_sign_counter[offset - actual_message_len_incl_header]; 890 } 891 892 // generic cmac calculation 893 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])){ 894 // Generalized CMAC 895 memcpy(sm_cmac_k, key, 16); 896 memset(sm_cmac_x, 0, 16); 897 sm_cmac_block_current = 0; 898 sm_cmac_message_len = message_len; 899 sm_cmac_done_handler = done_callback; 900 sm_cmac_get_byte = get_byte_callback; 901 902 // step 2: n := ceil(len/const_Bsize); 903 sm_cmac_block_count = (sm_cmac_message_len + 15) / 16; 904 905 // step 3: .. 906 if (sm_cmac_block_count==0){ 907 sm_cmac_block_count = 1; 908 } 909 log_info("sm_cmac_general_start: len %u, block count %u", sm_cmac_message_len, sm_cmac_block_count); 910 911 // first, we need to compute l for k1, k2, and m_last 912 sm_cmac_state = CMAC_CALC_SUBKEYS; 913 914 // let's go 915 sm_run(); 916 } 917 918 // cmac for ATT Message signing 919 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)){ 920 // ATT Message Signing 921 sm_cmac_header[0] = opcode; 922 little_endian_store_16(sm_cmac_header, 1, con_handle); 923 little_endian_store_32(sm_cmac_sign_counter, 0, sign_counter); 924 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 925 sm_cmac_message = message; 926 sm_cmac_general_start(k, total_message_len, &sm_cmac_message_get_byte, done_handler); 927 } 928 929 int sm_cmac_ready(void){ 930 return sm_cmac_state == CMAC_IDLE; 931 } 932 933 static void sm_cmac_handle_aes_engine_ready(void){ 934 switch (sm_cmac_state){ 935 case CMAC_CALC_SUBKEYS: { 936 sm_key_t const_zero; 937 memset(const_zero, 0, 16); 938 sm_cmac_next_state(); 939 sm_aes128_start(sm_cmac_k, const_zero, NULL); 940 break; 941 } 942 case CMAC_CALC_MI: { 943 int j; 944 sm_key_t y; 945 for (j=0;j<16;j++){ 946 y[j] = sm_cmac_x[j] ^ sm_cmac_get_byte(sm_cmac_block_current*16 + j); 947 } 948 sm_cmac_block_current++; 949 sm_cmac_next_state(); 950 sm_aes128_start(sm_cmac_k, y, NULL); 951 break; 952 } 953 case CMAC_CALC_MLAST: { 954 int i; 955 sm_key_t y; 956 for (i=0;i<16;i++){ 957 y[i] = sm_cmac_x[i] ^ sm_cmac_m_last[i]; 958 } 959 log_info_key("Y", y); 960 sm_cmac_block_current++; 961 sm_cmac_next_state(); 962 sm_aes128_start(sm_cmac_k, y, NULL); 963 break; 964 } 965 default: 966 log_info("sm_cmac_handle_aes_engine_ready called in state %u", sm_cmac_state); 967 break; 968 } 969 } 970 971 static void sm_cmac_handle_encryption_result(sm_key_t data){ 972 switch (sm_cmac_state){ 973 case CMAC_W4_SUBKEYS: { 974 sm_key_t k1; 975 memcpy(k1, data, 16); 976 sm_shift_left_by_one_bit_inplace(16, k1); 977 if (data[0] & 0x80){ 978 k1[15] ^= 0x87; 979 } 980 sm_key_t k2; 981 memcpy(k2, k1, 16); 982 sm_shift_left_by_one_bit_inplace(16, k2); 983 if (k1[0] & 0x80){ 984 k2[15] ^= 0x87; 985 } 986 987 log_info_key("k", sm_cmac_k); 988 log_info_key("k1", k1); 989 log_info_key("k2", k2); 990 991 // step 4: set m_last 992 int i; 993 if (sm_cmac_last_block_complete()){ 994 for (i=0;i<16;i++){ 995 sm_cmac_m_last[i] = sm_cmac_get_byte(sm_cmac_message_len - 16 + i) ^ k1[i]; 996 } 997 } else { 998 int valid_octets_in_last_block = sm_cmac_message_len & 0x0f; 999 for (i=0;i<16;i++){ 1000 if (i < valid_octets_in_last_block){ 1001 sm_cmac_m_last[i] = sm_cmac_get_byte((sm_cmac_message_len & 0xfff0) + i) ^ k2[i]; 1002 continue; 1003 } 1004 if (i == valid_octets_in_last_block){ 1005 sm_cmac_m_last[i] = 0x80 ^ k2[i]; 1006 continue; 1007 } 1008 sm_cmac_m_last[i] = k2[i]; 1009 } 1010 } 1011 1012 // next 1013 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1014 break; 1015 } 1016 case CMAC_W4_MI: 1017 memcpy(sm_cmac_x, data, 16); 1018 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1019 break; 1020 case CMAC_W4_MLAST: 1021 // done 1022 log_info("Setting CMAC Engine to IDLE"); 1023 sm_cmac_state = CMAC_IDLE; 1024 log_info_key("CMAC", data); 1025 sm_cmac_done_handler(data); 1026 break; 1027 default: 1028 log_info("sm_cmac_handle_encryption_result called in state %u", sm_cmac_state); 1029 break; 1030 } 1031 } 1032 1033 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 1034 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 1035 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 1036 switch (setup->sm_stk_generation_method){ 1037 case PK_RESP_INPUT: 1038 if (sm_conn->sm_role){ 1039 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1040 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1041 } else { 1042 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)); 1043 } 1044 break; 1045 case PK_INIT_INPUT: 1046 if (sm_conn->sm_role){ 1047 sm_notify_client_passkey(SM_EVENT_PASSKEY_DISPLAY_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 1048 } else { 1049 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1050 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1051 } 1052 break; 1053 case OK_BOTH_INPUT: 1054 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1055 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1056 break; 1057 case NK_BOTH_INPUT: 1058 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1059 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)); 1060 break; 1061 case JUST_WORKS: 1062 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1063 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1064 break; 1065 case OOB: 1066 // client already provided OOB data, let's skip notification. 1067 break; 1068 } 1069 } 1070 1071 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 1072 int recv_flags; 1073 if (sm_conn->sm_role){ 1074 // slave / responder 1075 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 1076 } else { 1077 // master / initiator 1078 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 1079 } 1080 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1081 return recv_flags == setup->sm_key_distribution_received_set; 1082 } 1083 1084 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1085 if (sm_active_connection == con_handle){ 1086 sm_timeout_stop(); 1087 sm_active_connection = 0; 1088 log_info("sm: connection 0x%x released setup context", con_handle); 1089 } 1090 } 1091 1092 static int sm_key_distribution_flags_for_auth_req(void){ 1093 int flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_SIGN; 1094 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1095 // encryption information only if bonding requested 1096 flags |= SM_KEYDIST_ENC_KEY; 1097 } 1098 return flags; 1099 } 1100 1101 static void sm_init_setup(sm_connection_t * sm_conn){ 1102 1103 // fill in sm setup 1104 setup->sm_state_vars = 0; 1105 sm_reset_tk(); 1106 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1107 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1108 1109 // query client for OOB data 1110 int have_oob_data = 0; 1111 if (sm_get_oob_data) { 1112 have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1113 } 1114 1115 sm_pairing_packet_t * local_packet; 1116 if (sm_conn->sm_role){ 1117 // slave 1118 local_packet = &setup->sm_s_pres; 1119 gap_advertisements_get_address(&setup->sm_s_addr_type, setup->sm_s_address); 1120 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1121 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1122 } else { 1123 // master 1124 local_packet = &setup->sm_m_preq; 1125 gap_advertisements_get_address(&setup->sm_m_addr_type, setup->sm_m_address); 1126 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1127 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1128 1129 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1130 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1131 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1132 } 1133 1134 uint8_t auth_req = sm_auth_req; 1135 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1136 sm_pairing_packet_set_oob_data_flag(*local_packet, have_oob_data); 1137 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1138 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1139 } 1140 1141 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1142 1143 sm_pairing_packet_t * remote_packet; 1144 int remote_key_request; 1145 if (sm_conn->sm_role){ 1146 // slave / responder 1147 remote_packet = &setup->sm_m_preq; 1148 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1149 } else { 1150 // master / initiator 1151 remote_packet = &setup->sm_s_pres; 1152 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1153 } 1154 1155 // check key size 1156 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1157 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1158 1159 // decide on STK generation method 1160 sm_setup_tk(); 1161 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1162 1163 // check if STK generation method is acceptable by client 1164 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1165 1166 // identical to responder 1167 sm_setup_key_distribution(remote_key_request); 1168 1169 // JUST WORKS doens't provide authentication 1170 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1171 1172 return 0; 1173 } 1174 1175 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1176 1177 // cache and reset context 1178 int matched_device_id = sm_address_resolution_test; 1179 address_resolution_mode_t mode = sm_address_resolution_mode; 1180 void * context = sm_address_resolution_context; 1181 1182 // reset context 1183 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1184 sm_address_resolution_context = NULL; 1185 sm_address_resolution_test = -1; 1186 hci_con_handle_t con_handle = 0; 1187 1188 sm_connection_t * sm_connection; 1189 uint16_t ediv; 1190 switch (mode){ 1191 case ADDRESS_RESOLUTION_GENERAL: 1192 break; 1193 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1194 sm_connection = (sm_connection_t *) context; 1195 con_handle = sm_connection->sm_handle; 1196 switch (event){ 1197 case ADDRESS_RESOLUTION_SUCEEDED: 1198 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1199 sm_connection->sm_le_db_index = matched_device_id; 1200 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1201 if (sm_connection->sm_role) break; 1202 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1203 sm_connection->sm_security_request_received = 0; 1204 sm_connection->sm_bonding_requested = 0; 1205 le_device_db_encryption_get(sm_connection->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 1206 if (ediv){ 1207 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1208 } else { 1209 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1210 } 1211 break; 1212 case ADDRESS_RESOLUTION_FAILED: 1213 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1214 if (sm_connection->sm_role) break; 1215 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1216 sm_connection->sm_security_request_received = 0; 1217 sm_connection->sm_bonding_requested = 0; 1218 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1219 break; 1220 } 1221 break; 1222 default: 1223 break; 1224 } 1225 1226 switch (event){ 1227 case ADDRESS_RESOLUTION_SUCEEDED: 1228 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1229 break; 1230 case ADDRESS_RESOLUTION_FAILED: 1231 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1232 break; 1233 } 1234 } 1235 1236 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1237 1238 int le_db_index = -1; 1239 1240 // lookup device based on IRK 1241 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1242 int i; 1243 for (i=0; i < le_device_db_count(); i++){ 1244 sm_key_t irk; 1245 bd_addr_t address; 1246 int address_type; 1247 le_device_db_info(i, &address_type, address, irk); 1248 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1249 log_info("sm: device found for IRK, updating"); 1250 le_db_index = i; 1251 break; 1252 } 1253 } 1254 } 1255 1256 // if not found, lookup via public address if possible 1257 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1258 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1259 int i; 1260 for (i=0; i < le_device_db_count(); i++){ 1261 bd_addr_t address; 1262 int address_type; 1263 le_device_db_info(i, &address_type, address, NULL); 1264 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1265 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1266 log_info("sm: device found for public address, updating"); 1267 le_db_index = i; 1268 break; 1269 } 1270 } 1271 } 1272 1273 // if not found, add to db 1274 if (le_db_index < 0) { 1275 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1276 } 1277 1278 if (le_db_index >= 0){ 1279 le_device_db_local_counter_set(le_db_index, 0); 1280 1281 // store local CSRK 1282 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1283 log_info("sm: store local CSRK"); 1284 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1285 le_device_db_local_counter_set(le_db_index, 0); 1286 } 1287 1288 // store remote CSRK 1289 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1290 log_info("sm: store remote CSRK"); 1291 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1292 le_device_db_remote_counter_set(le_db_index, 0); 1293 } 1294 1295 // store encryption information 1296 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION 1297 && setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 1298 log_info("sm: set encryption information (key size %u, authenticatd %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1299 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1300 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1301 } 1302 } 1303 1304 // keep le_db_index 1305 sm_conn->sm_le_db_index = le_db_index; 1306 } 1307 1308 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1309 setup->sm_pairing_failed_reason = reason; 1310 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1311 } 1312 1313 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1314 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1315 } 1316 1317 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1318 1319 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1320 static int sm_passkey_used(stk_generation_method_t method); 1321 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1322 1323 static void sm_log_ec_keypair(void){ 1324 log_info("d: %s", ec_d); 1325 log_info("X: %s", ec_qx); 1326 log_info("Y: %s", ec_qy); 1327 } 1328 1329 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1330 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1331 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1332 } else { 1333 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1334 } 1335 } 1336 1337 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1338 if (sm_conn->sm_role){ 1339 // Responder 1340 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1341 } else { 1342 // Initiator role 1343 switch (setup->sm_stk_generation_method){ 1344 case JUST_WORKS: 1345 sm_sc_prepare_dhkey_check(sm_conn); 1346 break; 1347 1348 case NK_BOTH_INPUT: 1349 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1350 break; 1351 case PK_INIT_INPUT: 1352 case PK_RESP_INPUT: 1353 case OK_BOTH_INPUT: 1354 if (setup->sm_passkey_bit < 20) { 1355 sm_sc_start_calculating_local_confirm(sm_conn); 1356 } else { 1357 sm_sc_prepare_dhkey_check(sm_conn); 1358 } 1359 break; 1360 case OOB: 1361 // TODO: implement SC OOB 1362 break; 1363 } 1364 } 1365 } 1366 1367 static uint8_t sm_sc_cmac_get_byte(uint16_t offset){ 1368 return sm_cmac_sc_buffer[offset]; 1369 } 1370 1371 static void sm_sc_cmac_done(uint8_t * hash){ 1372 log_info("sm_sc_cmac_done: "); 1373 log_info_hexdump(hash, 16); 1374 1375 sm_connection_t * sm_conn = sm_cmac_connection; 1376 sm_cmac_connection = NULL; 1377 1378 switch (sm_conn->sm_engine_state){ 1379 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1380 memcpy(setup->sm_local_confirm, hash, 16); 1381 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1382 break; 1383 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1384 // check 1385 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1386 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1387 break; 1388 } 1389 sm_sc_state_after_receiving_random(sm_conn); 1390 break; 1391 case SM_SC_W4_CALCULATE_G2: { 1392 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1393 big_endian_store_32(setup->sm_tk, 12, vab); 1394 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1395 sm_trigger_user_response(sm_conn); 1396 break; 1397 } 1398 case SM_SC_W4_CALCULATE_F5_SALT: 1399 memcpy(setup->sm_t, hash, 16); 1400 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1401 break; 1402 case SM_SC_W4_CALCULATE_F5_MACKEY: 1403 memcpy(setup->sm_mackey, hash, 16); 1404 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1405 break; 1406 case SM_SC_W4_CALCULATE_F5_LTK: 1407 memcpy(setup->sm_ltk, hash, 16); 1408 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1409 break; 1410 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1411 memcpy(setup->sm_local_dhkey_check, hash, 16); 1412 if (sm_conn->sm_role){ 1413 // responder 1414 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1415 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1416 } else { 1417 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1418 } 1419 } else { 1420 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1421 } 1422 break; 1423 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1424 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1425 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1426 break; 1427 } 1428 if (sm_conn->sm_role){ 1429 // responder 1430 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1431 } else { 1432 // initiator 1433 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1434 } 1435 break; 1436 default: 1437 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1438 break; 1439 } 1440 sm_run(); 1441 } 1442 1443 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){ 1444 const uint16_t message_len = 65; 1445 sm_cmac_connection = sm_conn; 1446 memcpy(sm_cmac_sc_buffer, u, 32); 1447 memcpy(sm_cmac_sc_buffer+32, v, 32); 1448 sm_cmac_sc_buffer[64] = z; 1449 log_info("f4 key"); 1450 log_info_hexdump(x, 16); 1451 log_info("f4 message"); 1452 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1453 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1454 } 1455 1456 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1457 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1458 static const uint8_t f5_length[] = { 0x01, 0x00}; 1459 1460 static void sm_sc_calculate_dhkey(sm_key256_t dhkey){ 1461 #ifdef USE_MBEDTLS_FOR_ECDH 1462 // da * Pb 1463 mbedtls_mpi d; 1464 mbedtls_ecp_point Q; 1465 mbedtls_ecp_point DH; 1466 mbedtls_mpi_init(&d); 1467 mbedtls_ecp_point_init(&Q); 1468 mbedtls_ecp_point_init(&DH); 1469 mbedtls_mpi_read_binary(&d, ec_d, 32); 1470 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 1471 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 1472 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 1473 mbedtls_ecp_mul(&mbedtls_ec_group, &DH, &d, &Q, NULL, NULL); 1474 mbedtls_mpi_write_binary(&DH.X, dhkey, 32); 1475 mbedtls_mpi_free(&d); 1476 mbedtls_ecp_point_free(&Q); 1477 mbedtls_ecp_point_free(&DH); 1478 #endif 1479 log_info("dhkey"); 1480 log_info_hexdump(dhkey, 32); 1481 } 1482 1483 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1484 // calculate DHKEY 1485 sm_key256_t dhkey; 1486 sm_sc_calculate_dhkey(dhkey); 1487 1488 // calculate salt for f5 1489 const uint16_t message_len = 32; 1490 sm_cmac_connection = sm_conn; 1491 memcpy(sm_cmac_sc_buffer, dhkey, message_len); 1492 sm_cmac_general_start(f5_salt, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1493 } 1494 1495 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){ 1496 const uint16_t message_len = 53; 1497 sm_cmac_connection = sm_conn; 1498 1499 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1500 sm_cmac_sc_buffer[0] = 0; 1501 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1502 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1503 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1504 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1505 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1506 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1507 log_info("f5 key"); 1508 log_info_hexdump(t, 16); 1509 log_info("f5 message for MacKey"); 1510 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1511 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1512 } 1513 1514 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1515 sm_key56_t bd_addr_master, bd_addr_slave; 1516 bd_addr_master[0] = setup->sm_m_addr_type; 1517 bd_addr_slave[0] = setup->sm_s_addr_type; 1518 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1519 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1520 if (sm_conn->sm_role){ 1521 // responder 1522 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1523 } else { 1524 // initiator 1525 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1526 } 1527 } 1528 1529 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1530 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1531 const uint16_t message_len = 53; 1532 sm_cmac_connection = sm_conn; 1533 sm_cmac_sc_buffer[0] = 1; 1534 // 1..52 setup before 1535 log_info("f5 key"); 1536 log_info_hexdump(t, 16); 1537 log_info("f5 message for LTK"); 1538 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1539 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1540 } 1541 1542 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1543 f5_ltk(sm_conn, setup->sm_t); 1544 } 1545 1546 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){ 1547 const uint16_t message_len = 65; 1548 sm_cmac_connection = sm_conn; 1549 memcpy(sm_cmac_sc_buffer, n1, 16); 1550 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1551 memcpy(sm_cmac_sc_buffer+32, r, 16); 1552 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1553 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1554 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1555 log_info("f6 key"); 1556 log_info_hexdump(w, 16); 1557 log_info("f6 message"); 1558 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1559 sm_cmac_general_start(w, 65, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1560 } 1561 1562 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1563 // - U is 256 bits 1564 // - V is 256 bits 1565 // - X is 128 bits 1566 // - Y is 128 bits 1567 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){ 1568 const uint16_t message_len = 80; 1569 sm_cmac_connection = sm_conn; 1570 memcpy(sm_cmac_sc_buffer, u, 32); 1571 memcpy(sm_cmac_sc_buffer+32, v, 32); 1572 memcpy(sm_cmac_sc_buffer+64, y, 16); 1573 log_info("g2 key"); 1574 log_info_hexdump(x, 16); 1575 log_info("g2 message"); 1576 log_info_hexdump(sm_cmac_sc_buffer, sizeof(sm_cmac_sc_buffer)); 1577 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1578 } 1579 1580 static void g2_calculate(sm_connection_t * sm_conn) { 1581 // calc Va if numeric comparison 1582 if (sm_conn->sm_role){ 1583 // responder 1584 g2_engine(sm_conn, setup->sm_peer_qx, ec_qx, setup->sm_peer_nonce, setup->sm_local_nonce);; 1585 } else { 1586 // initiator 1587 g2_engine(sm_conn, ec_qx, setup->sm_peer_qx, setup->sm_local_nonce, setup->sm_peer_nonce); 1588 } 1589 } 1590 1591 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1592 uint8_t z = 0; 1593 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1594 // some form of passkey 1595 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1596 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1597 setup->sm_passkey_bit++; 1598 } 1599 f4_engine(sm_conn, ec_qx, setup->sm_peer_qx, setup->sm_local_nonce, z); 1600 } 1601 1602 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1603 uint8_t z = 0; 1604 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1605 // some form of passkey 1606 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1607 // sm_passkey_bit was increased before sending confirm value 1608 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1609 } 1610 f4_engine(sm_conn, setup->sm_peer_qx, ec_qx, setup->sm_peer_nonce, z); 1611 } 1612 1613 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1614 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1615 } 1616 1617 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1618 // calculate DHKCheck 1619 sm_key56_t bd_addr_master, bd_addr_slave; 1620 bd_addr_master[0] = setup->sm_m_addr_type; 1621 bd_addr_slave[0] = setup->sm_s_addr_type; 1622 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1623 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1624 uint8_t iocap_a[3]; 1625 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1626 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1627 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1628 uint8_t iocap_b[3]; 1629 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1630 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1631 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1632 if (sm_conn->sm_role){ 1633 // responder 1634 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); 1635 } else { 1636 // initiator 1637 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); 1638 } 1639 } 1640 1641 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1642 // validate E = f6() 1643 sm_key56_t bd_addr_master, bd_addr_slave; 1644 bd_addr_master[0] = setup->sm_m_addr_type; 1645 bd_addr_slave[0] = setup->sm_s_addr_type; 1646 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1647 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1648 1649 uint8_t iocap_a[3]; 1650 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1651 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1652 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1653 uint8_t iocap_b[3]; 1654 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1655 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1656 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1657 if (sm_conn->sm_role){ 1658 // responder 1659 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); 1660 } else { 1661 // initiator 1662 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); 1663 } 1664 } 1665 #endif 1666 1667 static void sm_load_security_info(sm_connection_t * sm_connection){ 1668 int encryption_key_size; 1669 int authenticated; 1670 int authorized; 1671 1672 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1673 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1674 &encryption_key_size, &authenticated, &authorized); 1675 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1676 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1677 sm_connection->sm_connection_authenticated = authenticated; 1678 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1679 } 1680 1681 static void sm_run(void){ 1682 1683 btstack_linked_list_iterator_t it; 1684 1685 // assert that we can send at least commands 1686 if (!hci_can_send_command_packet_now()) return; 1687 1688 // 1689 // non-connection related behaviour 1690 // 1691 1692 // distributed key generation 1693 switch (dkg_state){ 1694 case DKG_CALC_IRK: 1695 // already busy? 1696 if (sm_aes128_state == SM_AES128_IDLE) { 1697 // IRK = d1(IR, 1, 0) 1698 sm_key_t d1_prime; 1699 sm_d1_d_prime(1, 0, d1_prime); // plaintext 1700 dkg_next_state(); 1701 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1702 return; 1703 } 1704 break; 1705 case DKG_CALC_DHK: 1706 // already busy? 1707 if (sm_aes128_state == SM_AES128_IDLE) { 1708 // DHK = d1(IR, 3, 0) 1709 sm_key_t d1_prime; 1710 sm_d1_d_prime(3, 0, d1_prime); // plaintext 1711 dkg_next_state(); 1712 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1713 return; 1714 } 1715 break; 1716 default: 1717 break; 1718 } 1719 1720 #ifdef USE_MBEDTLS_FOR_ECDH 1721 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 1722 sm_random_start(NULL); 1723 return; 1724 } 1725 #endif 1726 1727 // random address updates 1728 switch (rau_state){ 1729 case RAU_GET_RANDOM: 1730 rau_next_state(); 1731 sm_random_start(NULL); 1732 return; 1733 case RAU_GET_ENC: 1734 // already busy? 1735 if (sm_aes128_state == SM_AES128_IDLE) { 1736 sm_key_t r_prime; 1737 sm_ah_r_prime(sm_random_address, r_prime); 1738 rau_next_state(); 1739 sm_aes128_start(sm_persistent_irk, r_prime, NULL); 1740 return; 1741 } 1742 break; 1743 case RAU_SET_ADDRESS: 1744 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1745 rau_state = RAU_IDLE; 1746 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1747 return; 1748 default: 1749 break; 1750 } 1751 1752 // CMAC 1753 switch (sm_cmac_state){ 1754 case CMAC_CALC_SUBKEYS: 1755 case CMAC_CALC_MI: 1756 case CMAC_CALC_MLAST: 1757 // already busy? 1758 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1759 sm_cmac_handle_aes_engine_ready(); 1760 return; 1761 default: 1762 break; 1763 } 1764 1765 // CSRK Lookup 1766 // -- if csrk lookup ready, find connection that require csrk lookup 1767 if (sm_address_resolution_idle()){ 1768 hci_connections_get_iterator(&it); 1769 while(btstack_linked_list_iterator_has_next(&it)){ 1770 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1771 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1772 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1773 // and start lookup 1774 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); 1775 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1776 break; 1777 } 1778 } 1779 } 1780 1781 // -- if csrk lookup ready, resolved addresses for received addresses 1782 if (sm_address_resolution_idle()) { 1783 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1784 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1785 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1786 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1787 btstack_memory_sm_lookup_entry_free(entry); 1788 } 1789 } 1790 1791 // -- Continue with CSRK device lookup by public or resolvable private address 1792 if (!sm_address_resolution_idle()){ 1793 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_count()); 1794 while (sm_address_resolution_test < le_device_db_count()){ 1795 int addr_type; 1796 bd_addr_t addr; 1797 sm_key_t irk; 1798 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1799 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1800 1801 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1802 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1803 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1804 break; 1805 } 1806 1807 if (sm_address_resolution_addr_type == 0){ 1808 sm_address_resolution_test++; 1809 continue; 1810 } 1811 1812 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1813 1814 log_info("LE Device Lookup: calculate AH"); 1815 log_info_key("IRK", irk); 1816 1817 sm_key_t r_prime; 1818 sm_ah_r_prime(sm_address_resolution_address, r_prime); 1819 sm_address_resolution_ah_calculation_active = 1; 1820 sm_aes128_start(irk, r_prime, sm_address_resolution_context); // keep context 1821 return; 1822 } 1823 1824 if (sm_address_resolution_test >= le_device_db_count()){ 1825 log_info("LE Device Lookup: not found"); 1826 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1827 } 1828 } 1829 1830 1831 // 1832 // active connection handling 1833 // -- use loop to handle next connection if lock on setup context is released 1834 1835 while (1) { 1836 1837 // Find connections that requires setup context and make active if no other is locked 1838 hci_connections_get_iterator(&it); 1839 while(!sm_active_connection && btstack_linked_list_iterator_has_next(&it)){ 1840 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1841 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1842 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 1843 int done = 1; 1844 int err; 1845 switch (sm_connection->sm_engine_state) { 1846 case SM_RESPONDER_SEND_SECURITY_REQUEST: 1847 // send packet if possible, 1848 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 1849 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 1850 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 1851 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1852 } else { 1853 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1854 } 1855 // don't lock sxetup context yet 1856 done = 0; 1857 break; 1858 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 1859 sm_init_setup(sm_connection); 1860 // recover pairing request 1861 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 1862 err = sm_stk_generation_init(sm_connection); 1863 if (err){ 1864 setup->sm_pairing_failed_reason = err; 1865 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1866 break; 1867 } 1868 sm_timeout_start(sm_connection); 1869 // generate random number first, if we need to show passkey 1870 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 1871 sm_connection->sm_engine_state = SM_PH2_GET_RANDOM_TK; 1872 break; 1873 } 1874 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 1875 break; 1876 case SM_INITIATOR_PH0_HAS_LTK: 1877 sm_load_security_info(sm_connection); 1878 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 1879 break; 1880 case SM_RESPONDER_PH0_RECEIVED_LTK: 1881 switch (sm_connection->sm_irk_lookup_state){ 1882 case IRK_LOOKUP_SUCCEEDED:{ 1883 sm_load_security_info(sm_connection); 1884 sm_connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 1885 break; 1886 } 1887 case IRK_LOOKUP_FAILED: 1888 // assume that we don't have a LTK for ediv == 0 and random == null 1889 if (sm_connection->sm_local_ediv == 0 && sm_is_null_random(sm_connection->sm_local_rand)){ 1890 log_info("LTK Request: ediv & random are empty"); 1891 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1892 // TODO: no need to lock context yet -> done = 0; 1893 break; 1894 } 1895 // re-establish previously used LTK using Rand and EDIV 1896 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1897 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1898 // re-establish used key encryption size 1899 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1900 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1901 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1902 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1903 log_info("sm: received ltk request with key size %u, authenticated %u", 1904 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1905 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1906 break; 1907 default: 1908 // just wait until IRK lookup is completed 1909 // don't lock sxetup context yet 1910 done = 0; 1911 break; 1912 } 1913 break; 1914 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 1915 sm_init_setup(sm_connection); 1916 sm_timeout_start(sm_connection); 1917 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 1918 break; 1919 default: 1920 done = 0; 1921 break; 1922 } 1923 if (done){ 1924 sm_active_connection = sm_connection->sm_handle; 1925 log_info("sm: connection 0x%04x locked setup context as %s", sm_active_connection, sm_connection->sm_role ? "responder" : "initiator"); 1926 } 1927 } 1928 1929 // 1930 // active connection handling 1931 // 1932 1933 if (sm_active_connection == 0) return; 1934 1935 // assert that we could send a SM PDU - not needed for all of the following 1936 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 1937 l2cap_request_can_send_fix_channel_now_event(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1938 return; 1939 } 1940 1941 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection); 1942 if (!connection) return; 1943 1944 sm_key_t plaintext; 1945 int key_distribution_flags; 1946 1947 log_info("sm_run: state %u", connection->sm_engine_state); 1948 1949 // responding state 1950 switch (connection->sm_engine_state){ 1951 1952 // general 1953 case SM_GENERAL_SEND_PAIRING_FAILED: { 1954 uint8_t buffer[2]; 1955 buffer[0] = SM_CODE_PAIRING_FAILED; 1956 buffer[1] = setup->sm_pairing_failed_reason; 1957 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 1958 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1959 sm_done_for_handle(connection->sm_handle); 1960 break; 1961 } 1962 1963 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1964 case SM_SC_W2_GET_RANDOM_A: 1965 sm_random_start(connection); 1966 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_A; 1967 break; 1968 case SM_SC_W2_GET_RANDOM_B: 1969 sm_random_start(connection); 1970 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_B; 1971 break; 1972 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 1973 if (!sm_cmac_ready()) break; 1974 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 1975 sm_sc_calculate_local_confirm(connection); 1976 break; 1977 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 1978 if (!sm_cmac_ready()) break; 1979 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 1980 sm_sc_calculate_remote_confirm(connection); 1981 break; 1982 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 1983 if (!sm_cmac_ready()) break; 1984 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 1985 sm_sc_calculate_f6_for_dhkey_check(connection); 1986 break; 1987 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1988 if (!sm_cmac_ready()) break; 1989 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1990 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 1991 break; 1992 case SM_SC_W2_CALCULATE_F5_SALT: 1993 if (!sm_cmac_ready()) break; 1994 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 1995 f5_calculate_salt(connection); 1996 break; 1997 case SM_SC_W2_CALCULATE_F5_MACKEY: 1998 if (!sm_cmac_ready()) break; 1999 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2000 f5_calculate_mackey(connection); 2001 break; 2002 case SM_SC_W2_CALCULATE_F5_LTK: 2003 if (!sm_cmac_ready()) break; 2004 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2005 f5_calculate_ltk(connection); 2006 break; 2007 case SM_SC_W2_CALCULATE_G2: 2008 if (!sm_cmac_ready()) break; 2009 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2010 g2_calculate(connection); 2011 break; 2012 2013 #endif 2014 // initiator side 2015 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2016 sm_key_t peer_ltk_flipped; 2017 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2018 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2019 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2020 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2021 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2022 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2023 return; 2024 } 2025 2026 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2027 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2028 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2029 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2030 sm_timeout_reset(connection); 2031 break; 2032 2033 // responder side 2034 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2035 connection->sm_engine_state = SM_RESPONDER_IDLE; 2036 hci_send_cmd(&hci_le_long_term_key_negative_reply, connection->sm_handle); 2037 sm_done_for_handle(connection->sm_handle); 2038 return; 2039 2040 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2041 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2042 uint8_t buffer[65]; 2043 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2044 // 2045 reverse_256(ec_qx, &buffer[1]); 2046 reverse_256(ec_qy, &buffer[33]); 2047 2048 // stk generation method 2049 // passkey entry: notify app to show passkey or to request passkey 2050 switch (setup->sm_stk_generation_method){ 2051 case JUST_WORKS: 2052 case NK_BOTH_INPUT: 2053 if (connection->sm_role){ 2054 // responder 2055 sm_sc_start_calculating_local_confirm(connection); 2056 } else { 2057 // initiator 2058 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2059 } 2060 break; 2061 case PK_INIT_INPUT: 2062 case PK_RESP_INPUT: 2063 case OK_BOTH_INPUT: 2064 // use random TK for display 2065 memcpy(setup->sm_ra, setup->sm_tk, 16); 2066 memcpy(setup->sm_rb, setup->sm_tk, 16); 2067 setup->sm_passkey_bit = 0; 2068 2069 if (connection->sm_role){ 2070 // responder 2071 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2072 } else { 2073 // initiator 2074 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2075 } 2076 sm_trigger_user_response(connection); 2077 break; 2078 case OOB: 2079 // TODO: implement SC OOB 2080 break; 2081 } 2082 2083 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2084 sm_timeout_reset(connection); 2085 break; 2086 } 2087 case SM_SC_SEND_CONFIRMATION: { 2088 uint8_t buffer[17]; 2089 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2090 reverse_128(setup->sm_local_confirm, &buffer[1]); 2091 if (connection->sm_role){ 2092 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2093 } else { 2094 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2095 } 2096 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2097 sm_timeout_reset(connection); 2098 break; 2099 } 2100 case SM_SC_SEND_PAIRING_RANDOM: { 2101 uint8_t buffer[17]; 2102 buffer[0] = SM_CODE_PAIRING_RANDOM; 2103 reverse_128(setup->sm_local_nonce, &buffer[1]); 2104 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT && setup->sm_passkey_bit < 20){ 2105 if (connection->sm_role){ 2106 // responder 2107 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2108 } else { 2109 // initiator 2110 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2111 } 2112 } else { 2113 if (connection->sm_role){ 2114 // responder 2115 if (setup->sm_stk_generation_method == NK_BOTH_INPUT){ 2116 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2117 } else { 2118 sm_sc_prepare_dhkey_check(connection); 2119 } 2120 } else { 2121 // initiator 2122 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2123 } 2124 } 2125 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2126 sm_timeout_reset(connection); 2127 break; 2128 } 2129 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2130 uint8_t buffer[17]; 2131 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2132 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2133 2134 if (connection->sm_role){ 2135 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2136 } else { 2137 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2138 } 2139 2140 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2141 sm_timeout_reset(connection); 2142 break; 2143 } 2144 2145 #endif 2146 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2147 // echo initiator for now 2148 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2149 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2150 2151 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2152 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2153 if (setup->sm_use_secure_connections){ 2154 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2155 // skip LTK/EDIV for SC 2156 log_info("sm: dropping encryption information flag"); 2157 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2158 } 2159 #endif 2160 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); 2161 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); 2162 // update key distribution after ENC was dropped 2163 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2164 2165 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2166 sm_timeout_reset(connection); 2167 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2168 if (setup->sm_stk_generation_method == JUST_WORKS){ 2169 sm_trigger_user_response(connection); 2170 } 2171 return; 2172 2173 case SM_PH2_SEND_PAIRING_RANDOM: { 2174 uint8_t buffer[17]; 2175 buffer[0] = SM_CODE_PAIRING_RANDOM; 2176 reverse_128(setup->sm_local_random, &buffer[1]); 2177 if (connection->sm_role){ 2178 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2179 } else { 2180 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2181 } 2182 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2183 sm_timeout_reset(connection); 2184 break; 2185 } 2186 2187 case SM_PH2_GET_RANDOM_TK: 2188 case SM_PH2_C1_GET_RANDOM_A: 2189 case SM_PH2_C1_GET_RANDOM_B: 2190 case SM_PH3_GET_RANDOM: 2191 case SM_PH3_GET_DIV: 2192 sm_next_responding_state(connection); 2193 sm_random_start(connection); 2194 return; 2195 2196 case SM_PH2_C1_GET_ENC_B: 2197 case SM_PH2_C1_GET_ENC_D: 2198 // already busy? 2199 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2200 sm_next_responding_state(connection); 2201 sm_aes128_start(setup->sm_tk, setup->sm_c1_t3_value, connection); 2202 return; 2203 2204 case SM_PH3_LTK_GET_ENC: 2205 case SM_RESPONDER_PH4_LTK_GET_ENC: 2206 // already busy? 2207 if (sm_aes128_state == SM_AES128_IDLE) { 2208 sm_key_t d_prime; 2209 sm_d1_d_prime(setup->sm_local_div, 0, d_prime); 2210 sm_next_responding_state(connection); 2211 sm_aes128_start(sm_persistent_er, d_prime, connection); 2212 return; 2213 } 2214 break; 2215 2216 case SM_PH3_CSRK_GET_ENC: 2217 // already busy? 2218 if (sm_aes128_state == SM_AES128_IDLE) { 2219 sm_key_t d_prime; 2220 sm_d1_d_prime(setup->sm_local_div, 1, d_prime); 2221 sm_next_responding_state(connection); 2222 sm_aes128_start(sm_persistent_er, d_prime, connection); 2223 return; 2224 } 2225 break; 2226 2227 case SM_PH2_C1_GET_ENC_C: 2228 // already busy? 2229 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2230 // calculate m_confirm using aes128 engine - step 1 2231 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); 2232 sm_next_responding_state(connection); 2233 sm_aes128_start(setup->sm_tk, plaintext, connection); 2234 break; 2235 case SM_PH2_C1_GET_ENC_A: 2236 // already busy? 2237 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2238 // calculate confirm using aes128 engine - step 1 2239 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); 2240 sm_next_responding_state(connection); 2241 sm_aes128_start(setup->sm_tk, plaintext, connection); 2242 break; 2243 case SM_PH2_CALC_STK: 2244 // already busy? 2245 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2246 // calculate STK 2247 if (connection->sm_role){ 2248 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, plaintext); 2249 } else { 2250 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, plaintext); 2251 } 2252 sm_next_responding_state(connection); 2253 sm_aes128_start(setup->sm_tk, plaintext, connection); 2254 break; 2255 case SM_PH3_Y_GET_ENC: 2256 // already busy? 2257 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2258 // PH3B2 - calculate Y from - enc 2259 // Y = dm(DHK, Rand) 2260 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2261 sm_next_responding_state(connection); 2262 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2263 return; 2264 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2265 uint8_t buffer[17]; 2266 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2267 reverse_128(setup->sm_local_confirm, &buffer[1]); 2268 if (connection->sm_role){ 2269 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2270 } else { 2271 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2272 } 2273 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2274 sm_timeout_reset(connection); 2275 return; 2276 } 2277 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2278 sm_key_t stk_flipped; 2279 reverse_128(setup->sm_ltk, stk_flipped); 2280 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2281 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2282 return; 2283 } 2284 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2285 sm_key_t stk_flipped; 2286 reverse_128(setup->sm_ltk, stk_flipped); 2287 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2288 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2289 return; 2290 } 2291 case SM_RESPONDER_PH4_SEND_LTK: { 2292 sm_key_t ltk_flipped; 2293 reverse_128(setup->sm_ltk, ltk_flipped); 2294 connection->sm_engine_state = SM_RESPONDER_IDLE; 2295 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2296 return; 2297 } 2298 case SM_RESPONDER_PH4_Y_GET_ENC: 2299 // already busy? 2300 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2301 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2302 // Y = dm(DHK, Rand) 2303 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2304 sm_next_responding_state(connection); 2305 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2306 return; 2307 2308 case SM_PH3_DISTRIBUTE_KEYS: 2309 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2310 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2311 uint8_t buffer[17]; 2312 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2313 reverse_128(setup->sm_ltk, &buffer[1]); 2314 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2315 sm_timeout_reset(connection); 2316 return; 2317 } 2318 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2319 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2320 uint8_t buffer[11]; 2321 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2322 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2323 reverse_64(setup->sm_local_rand, &buffer[3]); 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_IDENTITY_INFORMATION){ 2329 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2330 uint8_t buffer[17]; 2331 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2332 reverse_128(sm_persistent_irk, &buffer[1]); 2333 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2334 sm_timeout_reset(connection); 2335 return; 2336 } 2337 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2338 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2339 bd_addr_t local_address; 2340 uint8_t buffer[8]; 2341 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2342 gap_advertisements_get_address(&buffer[1], local_address); 2343 reverse_bd_addr(local_address, &buffer[2]); 2344 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2345 sm_timeout_reset(connection); 2346 return; 2347 } 2348 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2349 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2350 2351 // hack to reproduce test runs 2352 if (test_use_fixed_local_csrk){ 2353 memset(setup->sm_local_csrk, 0xcc, 16); 2354 } 2355 2356 uint8_t buffer[17]; 2357 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2358 reverse_128(setup->sm_local_csrk, &buffer[1]); 2359 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2360 sm_timeout_reset(connection); 2361 return; 2362 } 2363 2364 // keys are sent 2365 if (connection->sm_role){ 2366 // slave -> receive master keys if any 2367 if (sm_key_distribution_all_received(connection)){ 2368 sm_key_distribution_handle_all_received(connection); 2369 connection->sm_engine_state = SM_RESPONDER_IDLE; 2370 sm_done_for_handle(connection->sm_handle); 2371 } else { 2372 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2373 } 2374 } else { 2375 // master -> all done 2376 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2377 sm_done_for_handle(connection->sm_handle); 2378 } 2379 break; 2380 2381 default: 2382 break; 2383 } 2384 2385 // check again if active connection was released 2386 if (sm_active_connection) break; 2387 } 2388 } 2389 2390 // note: aes engine is ready as we just got the aes result 2391 static void sm_handle_encryption_result(uint8_t * data){ 2392 2393 sm_aes128_state = SM_AES128_IDLE; 2394 2395 if (sm_address_resolution_ah_calculation_active){ 2396 sm_address_resolution_ah_calculation_active = 0; 2397 // compare calulated address against connecting device 2398 uint8_t hash[3]; 2399 reverse_24(data, hash); 2400 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2401 log_info("LE Device Lookup: matched resolvable private address"); 2402 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2403 return; 2404 } 2405 // no match, try next 2406 sm_address_resolution_test++; 2407 return; 2408 } 2409 2410 switch (dkg_state){ 2411 case DKG_W4_IRK: 2412 reverse_128(data, sm_persistent_irk); 2413 log_info_key("irk", sm_persistent_irk); 2414 dkg_next_state(); 2415 return; 2416 case DKG_W4_DHK: 2417 reverse_128(data, sm_persistent_dhk); 2418 log_info_key("dhk", sm_persistent_dhk); 2419 dkg_next_state(); 2420 // SM Init Finished 2421 return; 2422 default: 2423 break; 2424 } 2425 2426 switch (rau_state){ 2427 case RAU_W4_ENC: 2428 reverse_24(data, &sm_random_address[3]); 2429 rau_next_state(); 2430 return; 2431 default: 2432 break; 2433 } 2434 2435 switch (sm_cmac_state){ 2436 case CMAC_W4_SUBKEYS: 2437 case CMAC_W4_MI: 2438 case CMAC_W4_MLAST: 2439 { 2440 sm_key_t t; 2441 reverse_128(data, t); 2442 sm_cmac_handle_encryption_result(t); 2443 } 2444 return; 2445 default: 2446 break; 2447 } 2448 2449 // retrieve sm_connection provided to sm_aes128_start_encryption 2450 sm_connection_t * connection = (sm_connection_t*) sm_aes128_context; 2451 if (!connection) return; 2452 switch (connection->sm_engine_state){ 2453 case SM_PH2_C1_W4_ENC_A: 2454 case SM_PH2_C1_W4_ENC_C: 2455 { 2456 sm_key_t t2; 2457 reverse_128(data, t2); 2458 sm_c1_t3(t2, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2459 } 2460 sm_next_responding_state(connection); 2461 return; 2462 case SM_PH2_C1_W4_ENC_B: 2463 reverse_128(data, setup->sm_local_confirm); 2464 log_info_key("c1!", setup->sm_local_confirm); 2465 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2466 return; 2467 case SM_PH2_C1_W4_ENC_D: 2468 { 2469 sm_key_t peer_confirm_test; 2470 reverse_128(data, peer_confirm_test); 2471 log_info_key("c1!", peer_confirm_test); 2472 if (memcmp(setup->sm_peer_confirm, peer_confirm_test, 16) != 0){ 2473 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2474 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2475 return; 2476 } 2477 if (connection->sm_role){ 2478 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2479 } else { 2480 connection->sm_engine_state = SM_PH2_CALC_STK; 2481 } 2482 } 2483 return; 2484 case SM_PH2_W4_STK: 2485 reverse_128(data, setup->sm_ltk); 2486 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2487 log_info_key("stk", setup->sm_ltk); 2488 if (connection->sm_role){ 2489 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2490 } else { 2491 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2492 } 2493 return; 2494 case SM_PH3_Y_W4_ENC:{ 2495 sm_key_t y128; 2496 reverse_128(data, y128); 2497 setup->sm_local_y = big_endian_read_16(y128, 14); 2498 log_info_hex16("y", setup->sm_local_y); 2499 // PH3B3 - calculate EDIV 2500 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2501 log_info_hex16("ediv", setup->sm_local_ediv); 2502 // PH3B4 - calculate LTK - enc 2503 // LTK = d1(ER, DIV, 0)) 2504 connection->sm_engine_state = SM_PH3_LTK_GET_ENC; 2505 return; 2506 } 2507 case SM_RESPONDER_PH4_Y_W4_ENC:{ 2508 sm_key_t y128; 2509 reverse_128(data, y128); 2510 setup->sm_local_y = big_endian_read_16(y128, 14); 2511 log_info_hex16("y", setup->sm_local_y); 2512 2513 // PH3B3 - calculate DIV 2514 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2515 log_info_hex16("ediv", setup->sm_local_ediv); 2516 // PH3B4 - calculate LTK - enc 2517 // LTK = d1(ER, DIV, 0)) 2518 connection->sm_engine_state = SM_RESPONDER_PH4_LTK_GET_ENC; 2519 return; 2520 } 2521 case SM_PH3_LTK_W4_ENC: 2522 reverse_128(data, setup->sm_ltk); 2523 log_info_key("ltk", setup->sm_ltk); 2524 // calc CSRK next 2525 connection->sm_engine_state = SM_PH3_CSRK_GET_ENC; 2526 return; 2527 case SM_PH3_CSRK_W4_ENC: 2528 reverse_128(data, setup->sm_local_csrk); 2529 log_info_key("csrk", setup->sm_local_csrk); 2530 if (setup->sm_key_distribution_send_set){ 2531 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2532 } else { 2533 // no keys to send, just continue 2534 if (connection->sm_role){ 2535 // slave -> receive master keys 2536 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2537 } else { 2538 // master -> all done 2539 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2540 sm_done_for_handle(connection->sm_handle); 2541 } 2542 } 2543 return; 2544 case SM_RESPONDER_PH4_LTK_W4_ENC: 2545 reverse_128(data, setup->sm_ltk); 2546 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2547 log_info_key("ltk", setup->sm_ltk); 2548 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK; 2549 return; 2550 default: 2551 break; 2552 } 2553 } 2554 2555 #ifdef USE_MBEDTLS_FOR_ECDH 2556 2557 static int sm_generate_f_rng(void * context, unsigned char * buffer, size_t size){ 2558 int offset = setup->sm_passkey_bit; 2559 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, offset); 2560 while (size) { 2561 if (offset < 32){ 2562 *buffer++ = setup->sm_peer_qx[offset++]; 2563 } else { 2564 *buffer++ = setup->sm_peer_qx[offset++ - 32]; 2565 } 2566 size--; 2567 } 2568 setup->sm_passkey_bit = offset; 2569 return 0; 2570 } 2571 #endif 2572 2573 // note: random generator is ready. this doesn NOT imply that aes engine is unused! 2574 static void sm_handle_random_result(uint8_t * data){ 2575 2576 #ifdef USE_MBEDTLS_FOR_ECDH 2577 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 2578 int num_bytes = setup->sm_passkey_bit; 2579 if (num_bytes < 32){ 2580 memcpy(&setup->sm_peer_qx[num_bytes], data, 8); 2581 } else { 2582 memcpy(&setup->sm_peer_qx[num_bytes-32], data, 8); 2583 } 2584 num_bytes += 8; 2585 setup->sm_passkey_bit = num_bytes; 2586 2587 if (num_bytes >= 64){ 2588 // generate EC key 2589 setup->sm_passkey_bit = 0; 2590 mbedtls_mpi d; 2591 mbedtls_ecp_point P; 2592 mbedtls_mpi_init(&d); 2593 mbedtls_ecp_point_init(&P); 2594 mbedtls_ecp_gen_keypair(&mbedtls_ec_group, &d, &P, &sm_generate_f_rng, NULL); 2595 mbedtls_mpi_write_binary(&P.X, ec_qx, 16); 2596 mbedtls_mpi_write_binary(&P.Y, ec_qy, 16); 2597 mbedtls_mpi_write_binary(&d, ec_d, 16); 2598 sm_log_ec_keypair(); 2599 mbedtls_ecp_point_free(&P); 2600 mbedtls_mpi_free(&d); 2601 ec_key_generation_state = EC_KEY_GENERATION_DONE; 2602 2603 #if 1 2604 printf("test dhkey check\n"); 2605 sm_key256_t dhkey; 2606 memcpy(setup->sm_peer_qx, ec_qx, 32); 2607 memcpy(setup->sm_peer_qy, ec_qy, 32); 2608 sm_sc_calculate_dhkey(dhkey); 2609 #endif 2610 2611 } 2612 } 2613 #endif 2614 2615 switch (rau_state){ 2616 case RAU_W4_RANDOM: 2617 // non-resolvable vs. resolvable 2618 switch (gap_random_adress_type){ 2619 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2620 // resolvable: use random as prand and calc address hash 2621 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2622 memcpy(sm_random_address, data, 3); 2623 sm_random_address[0] &= 0x3f; 2624 sm_random_address[0] |= 0x40; 2625 rau_state = RAU_GET_ENC; 2626 break; 2627 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2628 default: 2629 // "The two most significant bits of the address shall be equal to ‘0’"" 2630 memcpy(sm_random_address, data, 6); 2631 sm_random_address[0] &= 0x3f; 2632 rau_state = RAU_SET_ADDRESS; 2633 break; 2634 } 2635 return; 2636 default: 2637 break; 2638 } 2639 2640 // retrieve sm_connection provided to sm_random_start 2641 sm_connection_t * connection = (sm_connection_t *) sm_random_context; 2642 if (!connection) return; 2643 switch (connection->sm_engine_state){ 2644 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2645 case SM_SC_W4_GET_RANDOM_A: 2646 memcpy(&setup->sm_local_nonce[0], data, 8); 2647 connection->sm_engine_state = SM_SC_W2_GET_RANDOM_B; 2648 break; 2649 case SM_SC_W4_GET_RANDOM_B: 2650 memcpy(&setup->sm_local_nonce[8], data, 8); 2651 // initiator & jw/nc -> send pairing random 2652 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2653 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2654 break; 2655 } else { 2656 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2657 } 2658 break; 2659 #endif 2660 2661 case SM_PH2_W4_RANDOM_TK: 2662 { 2663 // map random to 0-999999 without speding much cycles on a modulus operation 2664 uint32_t tk = little_endian_read_32(data,0); 2665 tk = tk & 0xfffff; // 1048575 2666 if (tk >= 999999){ 2667 tk = tk - 999999; 2668 } 2669 sm_reset_tk(); 2670 big_endian_store_32(setup->sm_tk, 12, tk); 2671 if (connection->sm_role){ 2672 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2673 } else { 2674 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2675 sm_trigger_user_response(connection); 2676 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2677 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2678 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 2679 } 2680 } 2681 return; 2682 } 2683 case SM_PH2_C1_W4_RANDOM_A: 2684 memcpy(&setup->sm_local_random[0], data, 8); // random endinaness 2685 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_B; 2686 return; 2687 case SM_PH2_C1_W4_RANDOM_B: 2688 memcpy(&setup->sm_local_random[8], data, 8); // random endinaness 2689 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2690 return; 2691 case SM_PH3_W4_RANDOM: 2692 reverse_64(data, setup->sm_local_rand); 2693 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2694 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2695 // no db for authenticated flag hack: store flag in bit 4 of LSB 2696 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2697 connection->sm_engine_state = SM_PH3_GET_DIV; 2698 return; 2699 case SM_PH3_W4_DIV: 2700 // use 16 bit from random value as div 2701 setup->sm_local_div = big_endian_read_16(data, 0); 2702 log_info_hex16("div", setup->sm_local_div); 2703 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2704 return; 2705 default: 2706 break; 2707 } 2708 } 2709 2710 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2711 2712 sm_connection_t * sm_conn; 2713 hci_con_handle_t con_handle; 2714 2715 switch (packet_type) { 2716 2717 case HCI_EVENT_PACKET: 2718 switch (hci_event_packet_get_type(packet)) { 2719 2720 case BTSTACK_EVENT_STATE: 2721 // bt stack activated, get started 2722 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2723 log_info("HCI Working!"); 2724 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 2725 rau_state = RAU_IDLE; 2726 #ifdef USE_MBEDTLS_FOR_ECDH 2727 if (!sm_have_ec_keypair){ 2728 setup->sm_passkey_bit = 0; 2729 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 2730 } 2731 #endif 2732 sm_run(); 2733 } 2734 break; 2735 2736 case HCI_EVENT_LE_META: 2737 switch (packet[2]) { 2738 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2739 2740 log_info("sm: connected"); 2741 2742 if (packet[3]) return; // connection failed 2743 2744 con_handle = little_endian_read_16(packet, 4); 2745 sm_conn = sm_get_connection_for_handle(con_handle); 2746 if (!sm_conn) break; 2747 2748 sm_conn->sm_handle = con_handle; 2749 sm_conn->sm_role = packet[6]; 2750 sm_conn->sm_peer_addr_type = packet[7]; 2751 reverse_bd_addr(&packet[8], 2752 sm_conn->sm_peer_address); 2753 2754 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2755 2756 // reset security properties 2757 sm_conn->sm_connection_encrypted = 0; 2758 sm_conn->sm_connection_authenticated = 0; 2759 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2760 sm_conn->sm_le_db_index = -1; 2761 2762 // prepare CSRK lookup (does not involve setup) 2763 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2764 2765 // just connected -> everything else happens in sm_run() 2766 if (sm_conn->sm_role){ 2767 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2768 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2769 if (sm_slave_request_security) { 2770 // request security if requested by app 2771 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2772 } else { 2773 // otherwise, wait for pairing request 2774 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2775 } 2776 } 2777 break; 2778 } else { 2779 // master 2780 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2781 } 2782 break; 2783 2784 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2785 con_handle = little_endian_read_16(packet, 3); 2786 sm_conn = sm_get_connection_for_handle(con_handle); 2787 if (!sm_conn) break; 2788 2789 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2790 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2791 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2792 break; 2793 } 2794 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 2795 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2796 break; 2797 } 2798 2799 // store rand and ediv 2800 reverse_64(&packet[5], sm_conn->sm_local_rand); 2801 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2802 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK; 2803 break; 2804 2805 default: 2806 break; 2807 } 2808 break; 2809 2810 case HCI_EVENT_ENCRYPTION_CHANGE: 2811 con_handle = little_endian_read_16(packet, 3); 2812 sm_conn = sm_get_connection_for_handle(con_handle); 2813 if (!sm_conn) break; 2814 2815 sm_conn->sm_connection_encrypted = packet[5]; 2816 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 2817 sm_conn->sm_actual_encryption_key_size); 2818 log_info("event handler, state %u", sm_conn->sm_engine_state); 2819 if (!sm_conn->sm_connection_encrypted) break; 2820 // continue if part of initial pairing 2821 switch (sm_conn->sm_engine_state){ 2822 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2823 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2824 sm_done_for_handle(sm_conn->sm_handle); 2825 break; 2826 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2827 if (sm_conn->sm_role){ 2828 // slave 2829 if (setup->sm_use_secure_connections){ 2830 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2831 } else { 2832 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2833 } 2834 } else { 2835 // master 2836 if (sm_key_distribution_all_received(sm_conn)){ 2837 // skip receiving keys as there are none 2838 sm_key_distribution_handle_all_received(sm_conn); 2839 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2840 } else { 2841 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2842 } 2843 } 2844 break; 2845 default: 2846 break; 2847 } 2848 break; 2849 2850 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 2851 con_handle = little_endian_read_16(packet, 3); 2852 sm_conn = sm_get_connection_for_handle(con_handle); 2853 if (!sm_conn) break; 2854 2855 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 2856 log_info("event handler, state %u", sm_conn->sm_engine_state); 2857 // continue if part of initial pairing 2858 switch (sm_conn->sm_engine_state){ 2859 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2860 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2861 sm_done_for_handle(sm_conn->sm_handle); 2862 break; 2863 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2864 if (sm_conn->sm_role){ 2865 // slave 2866 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2867 } else { 2868 // master 2869 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2870 } 2871 break; 2872 default: 2873 break; 2874 } 2875 break; 2876 2877 2878 case HCI_EVENT_DISCONNECTION_COMPLETE: 2879 con_handle = little_endian_read_16(packet, 3); 2880 sm_done_for_handle(con_handle); 2881 sm_conn = sm_get_connection_for_handle(con_handle); 2882 if (!sm_conn) break; 2883 2884 // delete stored bonding on disconnect with authentication failure in ph0 2885 if (sm_conn->sm_role == 0 2886 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 2887 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 2888 le_device_db_remove(sm_conn->sm_le_db_index); 2889 } 2890 2891 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 2892 sm_conn->sm_handle = 0; 2893 break; 2894 2895 case HCI_EVENT_COMMAND_COMPLETE: 2896 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 2897 sm_handle_encryption_result(&packet[6]); 2898 break; 2899 } 2900 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 2901 sm_handle_random_result(&packet[6]); 2902 break; 2903 } 2904 break; 2905 default: 2906 break; 2907 } 2908 break; 2909 default: 2910 break; 2911 } 2912 2913 sm_run(); 2914 } 2915 2916 static inline int sm_calc_actual_encryption_key_size(int other){ 2917 if (other < sm_min_encryption_key_size) return 0; 2918 if (other < sm_max_encryption_key_size) return other; 2919 return sm_max_encryption_key_size; 2920 } 2921 2922 2923 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 2924 switch (method){ 2925 case JUST_WORKS: 2926 case NK_BOTH_INPUT: 2927 return 1; 2928 default: 2929 return 0; 2930 } 2931 } 2932 // responder 2933 2934 static int sm_passkey_used(stk_generation_method_t method){ 2935 switch (method){ 2936 case PK_RESP_INPUT: 2937 return 1; 2938 default: 2939 return 0; 2940 } 2941 } 2942 2943 /** 2944 * @return ok 2945 */ 2946 static int sm_validate_stk_generation_method(void){ 2947 // check if STK generation method is acceptable by client 2948 switch (setup->sm_stk_generation_method){ 2949 case JUST_WORKS: 2950 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 2951 case PK_RESP_INPUT: 2952 case PK_INIT_INPUT: 2953 case OK_BOTH_INPUT: 2954 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 2955 case OOB: 2956 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 2957 case NK_BOTH_INPUT: 2958 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 2959 return 1; 2960 default: 2961 return 0; 2962 } 2963 } 2964 2965 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 2966 2967 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 2968 sm_run(); 2969 } 2970 2971 if (packet_type != SM_DATA_PACKET) return; 2972 2973 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 2974 if (!sm_conn) return; 2975 2976 if (packet[0] == SM_CODE_PAIRING_FAILED){ 2977 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2978 return; 2979 } 2980 2981 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, packet[0]); 2982 2983 int err; 2984 2985 switch (sm_conn->sm_engine_state){ 2986 2987 // a sm timeout requries a new physical connection 2988 case SM_GENERAL_TIMEOUT: 2989 return; 2990 2991 // Initiator 2992 case SM_INITIATOR_CONNECTED: 2993 if ((packet[0] != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 2994 sm_pdu_received_in_wrong_state(sm_conn); 2995 break; 2996 } 2997 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 2998 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 2999 break; 3000 } 3001 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 3002 uint16_t ediv; 3003 sm_key_t ltk; 3004 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3005 if (!sm_is_null_key(ltk) || ediv){ 3006 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3007 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3008 } else { 3009 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3010 } 3011 break; 3012 } 3013 // otherwise, store security request 3014 sm_conn->sm_security_request_received = 1; 3015 break; 3016 3017 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3018 if (packet[0] != SM_CODE_PAIRING_RESPONSE){ 3019 sm_pdu_received_in_wrong_state(sm_conn); 3020 break; 3021 } 3022 // store pairing request 3023 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3024 err = sm_stk_generation_init(sm_conn); 3025 if (err){ 3026 setup->sm_pairing_failed_reason = err; 3027 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3028 break; 3029 } 3030 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3031 if (setup->sm_use_secure_connections){ 3032 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3033 if (setup->sm_stk_generation_method == JUST_WORKS){ 3034 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3035 sm_trigger_user_response(sm_conn); 3036 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3037 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3038 } 3039 } else { 3040 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3041 } 3042 break; 3043 } 3044 #endif 3045 // generate random number first, if we need to show passkey 3046 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3047 sm_conn->sm_engine_state = SM_PH2_GET_RANDOM_TK; 3048 break; 3049 } 3050 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3051 sm_trigger_user_response(sm_conn); 3052 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3053 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3054 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3055 } 3056 break; 3057 3058 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3059 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3060 sm_pdu_received_in_wrong_state(sm_conn); 3061 break; 3062 } 3063 3064 // store s_confirm 3065 reverse_128(&packet[1], setup->sm_peer_confirm); 3066 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3067 break; 3068 3069 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3070 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3071 sm_pdu_received_in_wrong_state(sm_conn); 3072 break;; 3073 } 3074 3075 // received random value 3076 reverse_128(&packet[1], setup->sm_peer_random); 3077 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3078 break; 3079 3080 // Responder 3081 case SM_RESPONDER_IDLE: 3082 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3083 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3084 if (packet[0] != SM_CODE_PAIRING_REQUEST){ 3085 sm_pdu_received_in_wrong_state(sm_conn); 3086 break;; 3087 } 3088 3089 // store pairing request 3090 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3091 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3092 break; 3093 3094 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3095 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3096 if (packet[0] != SM_CODE_PAIRING_PUBLIC_KEY){ 3097 sm_pdu_received_in_wrong_state(sm_conn); 3098 break; 3099 } 3100 3101 // store public key for DH Key calculation 3102 reverse_256(&packet[01], setup->sm_peer_qx); 3103 reverse_256(&packet[33], setup->sm_peer_qy); 3104 3105 #ifdef USE_MBEDTLS_FOR_ECDH 3106 // validate public key 3107 mbedtls_ecp_point Q; 3108 mbedtls_ecp_point_init( &Q ); 3109 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 3110 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 3111 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 3112 err = mbedtls_ecp_check_pubkey(&mbedtls_ec_group, &Q); 3113 mbedtls_ecp_point_free( & Q); 3114 if (err){ 3115 log_error("sm: peer public key invalid %x", err); 3116 // uses "unspecified reason", there is no "public key invalid" error code 3117 sm_pdu_received_in_wrong_state(sm_conn); 3118 break; 3119 } 3120 3121 #endif 3122 if (sm_conn->sm_role){ 3123 // responder 3124 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3125 } else { 3126 // initiator 3127 // stk generation method 3128 // passkey entry: notify app to show passkey or to request passkey 3129 switch (setup->sm_stk_generation_method){ 3130 case JUST_WORKS: 3131 case NK_BOTH_INPUT: 3132 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3133 break; 3134 case PK_RESP_INPUT: 3135 sm_sc_start_calculating_local_confirm(sm_conn); 3136 break; 3137 case PK_INIT_INPUT: 3138 case OK_BOTH_INPUT: 3139 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3140 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3141 break; 3142 } 3143 sm_sc_start_calculating_local_confirm(sm_conn); 3144 break; 3145 case OOB: 3146 // TODO: implement SC OOB 3147 break; 3148 } 3149 } 3150 break; 3151 3152 case SM_SC_W4_CONFIRMATION: 3153 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3154 sm_pdu_received_in_wrong_state(sm_conn); 3155 break; 3156 } 3157 // received confirm value 3158 reverse_128(&packet[1], setup->sm_peer_confirm); 3159 3160 if (sm_conn->sm_role){ 3161 // responder 3162 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3163 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3164 // still waiting for passkey 3165 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3166 break; 3167 } 3168 } 3169 sm_sc_start_calculating_local_confirm(sm_conn); 3170 } else { 3171 // initiator 3172 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3173 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3174 } else { 3175 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3176 } 3177 } 3178 break; 3179 3180 case SM_SC_W4_PAIRING_RANDOM: 3181 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3182 sm_pdu_received_in_wrong_state(sm_conn); 3183 break; 3184 } 3185 3186 // received random value 3187 reverse_128(&packet[1], setup->sm_peer_nonce); 3188 3189 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3190 // only check for JUST WORK/NC in initiator role AND passkey entry 3191 int passkey_entry = sm_passkey_used(setup->sm_stk_generation_method); 3192 if (sm_conn->sm_role || passkey_entry) { 3193 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3194 } 3195 3196 sm_sc_state_after_receiving_random(sm_conn); 3197 break; 3198 3199 case SM_SC_W2_CALCULATE_G2: 3200 case SM_SC_W4_CALCULATE_G2: 3201 case SM_SC_W2_CALCULATE_F5_SALT: 3202 case SM_SC_W4_CALCULATE_F5_SALT: 3203 case SM_SC_W2_CALCULATE_F5_MACKEY: 3204 case SM_SC_W4_CALCULATE_F5_MACKEY: 3205 case SM_SC_W2_CALCULATE_F5_LTK: 3206 case SM_SC_W4_CALCULATE_F5_LTK: 3207 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3208 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3209 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3210 if (packet[0] != SM_CODE_PAIRING_DHKEY_CHECK){ 3211 sm_pdu_received_in_wrong_state(sm_conn); 3212 break; 3213 } 3214 // store DHKey Check 3215 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3216 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3217 3218 // have we been only waiting for dhkey check command? 3219 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3220 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3221 } 3222 break; 3223 #endif 3224 3225 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3226 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3227 sm_pdu_received_in_wrong_state(sm_conn); 3228 break; 3229 } 3230 3231 // received confirm value 3232 reverse_128(&packet[1], setup->sm_peer_confirm); 3233 3234 // notify client to hide shown passkey 3235 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3236 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3237 } 3238 3239 // handle user cancel pairing? 3240 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3241 setup->sm_pairing_failed_reason = SM_REASON_PASSKEYT_ENTRY_FAILED; 3242 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3243 break; 3244 } 3245 3246 // wait for user action? 3247 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3248 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3249 break; 3250 } 3251 3252 // calculate and send local_confirm 3253 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3254 break; 3255 3256 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3257 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3258 sm_pdu_received_in_wrong_state(sm_conn); 3259 break;; 3260 } 3261 3262 // received random value 3263 reverse_128(&packet[1], setup->sm_peer_random); 3264 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3265 break; 3266 3267 case SM_PH3_RECEIVE_KEYS: 3268 switch(packet[0]){ 3269 case SM_CODE_ENCRYPTION_INFORMATION: 3270 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3271 reverse_128(&packet[1], setup->sm_peer_ltk); 3272 break; 3273 3274 case SM_CODE_MASTER_IDENTIFICATION: 3275 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3276 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3277 reverse_64(&packet[3], setup->sm_peer_rand); 3278 break; 3279 3280 case SM_CODE_IDENTITY_INFORMATION: 3281 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3282 reverse_128(&packet[1], setup->sm_peer_irk); 3283 break; 3284 3285 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3286 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3287 setup->sm_peer_addr_type = packet[1]; 3288 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3289 break; 3290 3291 case SM_CODE_SIGNING_INFORMATION: 3292 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3293 reverse_128(&packet[1], setup->sm_peer_csrk); 3294 break; 3295 default: 3296 // Unexpected PDU 3297 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3298 break; 3299 } 3300 // done with key distribution? 3301 if (sm_key_distribution_all_received(sm_conn)){ 3302 3303 sm_key_distribution_handle_all_received(sm_conn); 3304 3305 if (sm_conn->sm_role){ 3306 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3307 sm_done_for_handle(sm_conn->sm_handle); 3308 } else { 3309 if (setup->sm_use_secure_connections){ 3310 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3311 } else { 3312 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3313 } 3314 } 3315 } 3316 break; 3317 default: 3318 // Unexpected PDU 3319 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3320 break; 3321 } 3322 3323 // try to send preparared packet 3324 sm_run(); 3325 } 3326 3327 // Security Manager Client API 3328 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data)){ 3329 sm_get_oob_data = get_oob_data_callback; 3330 } 3331 3332 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3333 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3334 } 3335 3336 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3337 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3338 } 3339 3340 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3341 sm_min_encryption_key_size = min_size; 3342 sm_max_encryption_key_size = max_size; 3343 } 3344 3345 void sm_set_authentication_requirements(uint8_t auth_req){ 3346 sm_auth_req = auth_req; 3347 } 3348 3349 void sm_set_io_capabilities(io_capability_t io_capability){ 3350 sm_io_capabilities = io_capability; 3351 } 3352 3353 void sm_set_request_security(int enable){ 3354 sm_slave_request_security = enable; 3355 } 3356 3357 void sm_set_er(sm_key_t er){ 3358 memcpy(sm_persistent_er, er, 16); 3359 } 3360 3361 void sm_set_ir(sm_key_t ir){ 3362 memcpy(sm_persistent_ir, ir, 16); 3363 } 3364 3365 // Testing support only 3366 void sm_test_set_irk(sm_key_t irk){ 3367 memcpy(sm_persistent_irk, irk, 16); 3368 sm_persistent_irk_ready = 1; 3369 } 3370 3371 void sm_test_use_fixed_local_csrk(void){ 3372 test_use_fixed_local_csrk = 1; 3373 } 3374 3375 void sm_init(void){ 3376 // set some (BTstack default) ER and IR 3377 int i; 3378 sm_key_t er; 3379 sm_key_t ir; 3380 for (i=0;i<16;i++){ 3381 er[i] = 0x30 + i; 3382 ir[i] = 0x90 + i; 3383 } 3384 sm_set_er(er); 3385 sm_set_ir(ir); 3386 // defaults 3387 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3388 | SM_STK_GENERATION_METHOD_OOB 3389 | SM_STK_GENERATION_METHOD_PASSKEY 3390 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3391 3392 sm_max_encryption_key_size = 16; 3393 sm_min_encryption_key_size = 7; 3394 3395 sm_cmac_state = CMAC_IDLE; 3396 dkg_state = DKG_W4_WORKING; 3397 rau_state = RAU_W4_WORKING; 3398 sm_aes128_state = SM_AES128_IDLE; 3399 sm_address_resolution_test = -1; // no private address to resolve yet 3400 sm_address_resolution_ah_calculation_active = 0; 3401 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3402 sm_address_resolution_general_queue = NULL; 3403 3404 gap_random_adress_update_period = 15 * 60 * 1000L; 3405 3406 sm_active_connection = 0; 3407 3408 test_use_fixed_local_csrk = 0; 3409 3410 // register for HCI Events from HCI 3411 hci_event_callback_registration.callback = &sm_event_packet_handler; 3412 hci_add_event_handler(&hci_event_callback_registration); 3413 3414 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3415 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3416 3417 #ifdef USE_MBEDTLS_FOR_ECDH 3418 ec_key_generation_state = EC_KEY_GENERATION_IDLE; 3419 3420 #ifndef HAVE_MALLOC 3421 sm_mbedtls_allocator_init(mbedtls_memory_buffer, sizeof(mbedtls_memory_buffer)); 3422 #endif 3423 mbedtls_ecp_group_init(&mbedtls_ec_group); 3424 mbedtls_ecp_group_load(&mbedtls_ec_group, MBEDTLS_ECP_DP_SECP256R1); 3425 3426 #if 0 3427 // test 3428 sm_test_use_fixed_ec_keypair(); 3429 if (sm_have_ec_keypair){ 3430 printf("test dhkey check\n"); 3431 sm_key256_t dhkey; 3432 memcpy(setup->sm_peer_qx, ec_qx, 32); 3433 memcpy(setup->sm_peer_qy, ec_qy, 32); 3434 sm_sc_calculate_dhkey(dhkey); 3435 } 3436 #endif 3437 #endif 3438 } 3439 3440 void sm_use_fixed_ec_keypair(uint8_t * qx, uint8_t * qy, uint8_t * d){ 3441 memcpy(ec_qx, qx, 32); 3442 memcpy(ec_qy, qy, 32); 3443 memcpy(ec_d, d, 32); 3444 sm_have_ec_keypair = 1; 3445 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3446 } 3447 3448 void sm_test_use_fixed_ec_keypair(void){ 3449 #ifdef USE_MBEDTLS_FOR_ECDH 3450 // use test keypair from spec 3451 mbedtls_mpi x; 3452 mbedtls_mpi_init(&x); 3453 mbedtls_mpi_read_string( &x, 16, "3f49f6d4a3c55f3874c9b3e3d2103f504aff607beb40b7995899b8a6cd3c1abd"); 3454 mbedtls_mpi_write_binary(&x, ec_d, 32); 3455 mbedtls_mpi_read_string( &x, 16, "20b003d2f297be2c5e2c83a7e9f9a5b9eff49111acf4fddbcc0301480e359de6"); 3456 mbedtls_mpi_write_binary(&x, ec_qx, 32); 3457 mbedtls_mpi_read_string( &x, 16, "dc809c49652aeb6d63329abf5a52155c766345c28fed3024741c8ed01589d28b"); 3458 mbedtls_mpi_write_binary(&x, ec_qy, 32); 3459 mbedtls_mpi_free(&x); 3460 #endif 3461 sm_have_ec_keypair = 1; 3462 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3463 } 3464 3465 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3466 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3467 if (!hci_con) return NULL; 3468 return &hci_con->sm_connection; 3469 } 3470 3471 // @returns 0 if not encrypted, 7-16 otherwise 3472 int sm_encryption_key_size(hci_con_handle_t con_handle){ 3473 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3474 if (!sm_conn) return 0; // wrong connection 3475 if (!sm_conn->sm_connection_encrypted) return 0; 3476 return sm_conn->sm_actual_encryption_key_size; 3477 } 3478 3479 int sm_authenticated(hci_con_handle_t con_handle){ 3480 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3481 if (!sm_conn) return 0; // wrong connection 3482 if (!sm_conn->sm_connection_encrypted) return 0; // unencrypted connection cannot be authenticated 3483 return sm_conn->sm_connection_authenticated; 3484 } 3485 3486 authorization_state_t sm_authorization_state(hci_con_handle_t con_handle){ 3487 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3488 if (!sm_conn) return AUTHORIZATION_UNKNOWN; // wrong connection 3489 if (!sm_conn->sm_connection_encrypted) return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized 3490 if (!sm_conn->sm_connection_authenticated) return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized 3491 return sm_conn->sm_connection_authorization_state; 3492 } 3493 3494 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3495 switch (sm_conn->sm_engine_state){ 3496 case SM_GENERAL_IDLE: 3497 case SM_RESPONDER_IDLE: 3498 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3499 sm_run(); 3500 break; 3501 default: 3502 break; 3503 } 3504 } 3505 3506 /** 3507 * @brief Trigger Security Request 3508 */ 3509 void sm_send_security_request(hci_con_handle_t con_handle){ 3510 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3511 if (!sm_conn) return; 3512 sm_send_security_request_for_connection(sm_conn); 3513 } 3514 3515 // request pairing 3516 void sm_request_pairing(hci_con_handle_t con_handle){ 3517 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3518 if (!sm_conn) return; // wrong connection 3519 3520 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3521 if (sm_conn->sm_role){ 3522 sm_send_security_request_for_connection(sm_conn); 3523 } else { 3524 // used as a trigger to start central/master/initiator security procedures 3525 uint16_t ediv; 3526 sm_key_t ltk; 3527 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3528 switch (sm_conn->sm_irk_lookup_state){ 3529 case IRK_LOOKUP_FAILED: 3530 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3531 break; 3532 case IRK_LOOKUP_SUCCEEDED: 3533 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3534 if (!sm_is_null_key(ltk) || ediv){ 3535 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3536 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3537 } else { 3538 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3539 } 3540 break; 3541 default: 3542 sm_conn->sm_bonding_requested = 1; 3543 break; 3544 } 3545 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3546 sm_conn->sm_bonding_requested = 1; 3547 } 3548 } 3549 sm_run(); 3550 } 3551 3552 // called by client app on authorization request 3553 void sm_authorization_decline(hci_con_handle_t con_handle){ 3554 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3555 if (!sm_conn) return; // wrong connection 3556 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3557 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3558 } 3559 3560 void sm_authorization_grant(hci_con_handle_t con_handle){ 3561 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3562 if (!sm_conn) return; // wrong connection 3563 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3564 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3565 } 3566 3567 // GAP Bonding API 3568 3569 void sm_bonding_decline(hci_con_handle_t con_handle){ 3570 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3571 if (!sm_conn) return; // wrong connection 3572 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3573 3574 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3575 switch (setup->sm_stk_generation_method){ 3576 case PK_RESP_INPUT: 3577 case PK_INIT_INPUT: 3578 case OK_BOTH_INPUT: 3579 sm_pairing_error(sm_conn, SM_GENERAL_SEND_PAIRING_FAILED); 3580 break; 3581 case NK_BOTH_INPUT: 3582 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 3583 break; 3584 case JUST_WORKS: 3585 case OOB: 3586 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 3587 break; 3588 } 3589 } 3590 sm_run(); 3591 } 3592 3593 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3594 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3595 if (!sm_conn) return; // wrong connection 3596 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3597 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3598 if (setup->sm_use_secure_connections){ 3599 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3600 } else { 3601 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3602 } 3603 } 3604 3605 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3606 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3607 sm_sc_prepare_dhkey_check(sm_conn); 3608 } 3609 #endif 3610 3611 sm_run(); 3612 } 3613 3614 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3615 // for now, it's the same 3616 sm_just_works_confirm(con_handle); 3617 } 3618 3619 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3620 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3621 if (!sm_conn) return; // wrong connection 3622 sm_reset_tk(); 3623 big_endian_store_32(setup->sm_tk, 12, passkey); 3624 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3625 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3626 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3627 } 3628 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3629 memcpy(setup->sm_ra, setup->sm_tk, 16); 3630 memcpy(setup->sm_rb, setup->sm_tk, 16); 3631 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3632 sm_sc_start_calculating_local_confirm(sm_conn); 3633 } 3634 #endif 3635 sm_run(); 3636 } 3637 3638 /** 3639 * @brief Identify device in LE Device DB 3640 * @param handle 3641 * @returns index from le_device_db or -1 if not found/identified 3642 */ 3643 int sm_le_device_index(hci_con_handle_t con_handle ){ 3644 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3645 if (!sm_conn) return -1; 3646 return sm_conn->sm_le_db_index; 3647 } 3648 3649 // GAP LE API 3650 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 3651 gap_random_address_update_stop(); 3652 gap_random_adress_type = random_address_type; 3653 if (random_address_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3654 gap_random_address_update_start(); 3655 gap_random_address_trigger(); 3656 } 3657 3658 gap_random_address_type_t gap_random_address_get_mode(void){ 3659 return gap_random_adress_type; 3660 } 3661 3662 void gap_random_address_set_update_period(int period_ms){ 3663 gap_random_adress_update_period = period_ms; 3664 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3665 gap_random_address_update_stop(); 3666 gap_random_address_update_start(); 3667 } 3668 3669 void gap_random_address_set(bd_addr_t addr){ 3670 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_OFF); 3671 memcpy(sm_random_address, addr, 6); 3672 rau_state = RAU_SET_ADDRESS; 3673 sm_run(); 3674 } 3675 3676 /* 3677 * @brief Set Advertisement Paramters 3678 * @param adv_int_min 3679 * @param adv_int_max 3680 * @param adv_type 3681 * @param direct_address_type 3682 * @param direct_address 3683 * @param channel_map 3684 * @param filter_policy 3685 * 3686 * @note own_address_type is used from gap_random_address_set_mode 3687 */ 3688 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 3689 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 3690 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, gap_random_adress_type, 3691 direct_address_typ, direct_address, channel_map, filter_policy); 3692 } 3693 3694