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("Elliptic curve: d"); 1325 log_info_hexdump(ec_d,32); 1326 log_info("Elliptic curve: X"); 1327 log_info_hexdump(ec_qx,32); 1328 log_info("Elliptic curve: Y"); 1329 log_info_hexdump(ec_qy,32); 1330 } 1331 1332 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1333 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1334 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1335 } else { 1336 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1337 } 1338 } 1339 1340 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1341 if (sm_conn->sm_role){ 1342 // Responder 1343 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1344 } else { 1345 // Initiator role 1346 switch (setup->sm_stk_generation_method){ 1347 case JUST_WORKS: 1348 sm_sc_prepare_dhkey_check(sm_conn); 1349 break; 1350 1351 case NK_BOTH_INPUT: 1352 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1353 break; 1354 case PK_INIT_INPUT: 1355 case PK_RESP_INPUT: 1356 case OK_BOTH_INPUT: 1357 if (setup->sm_passkey_bit < 20) { 1358 sm_sc_start_calculating_local_confirm(sm_conn); 1359 } else { 1360 sm_sc_prepare_dhkey_check(sm_conn); 1361 } 1362 break; 1363 case OOB: 1364 // TODO: implement SC OOB 1365 break; 1366 } 1367 } 1368 } 1369 1370 static uint8_t sm_sc_cmac_get_byte(uint16_t offset){ 1371 return sm_cmac_sc_buffer[offset]; 1372 } 1373 1374 static void sm_sc_cmac_done(uint8_t * hash){ 1375 log_info("sm_sc_cmac_done: "); 1376 log_info_hexdump(hash, 16); 1377 1378 sm_connection_t * sm_conn = sm_cmac_connection; 1379 sm_cmac_connection = NULL; 1380 1381 switch (sm_conn->sm_engine_state){ 1382 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1383 memcpy(setup->sm_local_confirm, hash, 16); 1384 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1385 break; 1386 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1387 // check 1388 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1389 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1390 break; 1391 } 1392 sm_sc_state_after_receiving_random(sm_conn); 1393 break; 1394 case SM_SC_W4_CALCULATE_G2: { 1395 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1396 big_endian_store_32(setup->sm_tk, 12, vab); 1397 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1398 sm_trigger_user_response(sm_conn); 1399 break; 1400 } 1401 case SM_SC_W4_CALCULATE_F5_SALT: 1402 memcpy(setup->sm_t, hash, 16); 1403 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1404 break; 1405 case SM_SC_W4_CALCULATE_F5_MACKEY: 1406 memcpy(setup->sm_mackey, hash, 16); 1407 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1408 break; 1409 case SM_SC_W4_CALCULATE_F5_LTK: 1410 memcpy(setup->sm_ltk, hash, 16); 1411 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1412 break; 1413 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1414 memcpy(setup->sm_local_dhkey_check, hash, 16); 1415 if (sm_conn->sm_role){ 1416 // responder 1417 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1418 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1419 } else { 1420 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1421 } 1422 } else { 1423 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1424 } 1425 break; 1426 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1427 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1428 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1429 break; 1430 } 1431 if (sm_conn->sm_role){ 1432 // responder 1433 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1434 } else { 1435 // initiator 1436 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1437 } 1438 break; 1439 default: 1440 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1441 break; 1442 } 1443 sm_run(); 1444 } 1445 1446 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){ 1447 const uint16_t message_len = 65; 1448 sm_cmac_connection = sm_conn; 1449 memcpy(sm_cmac_sc_buffer, u, 32); 1450 memcpy(sm_cmac_sc_buffer+32, v, 32); 1451 sm_cmac_sc_buffer[64] = z; 1452 log_info("f4 key"); 1453 log_info_hexdump(x, 16); 1454 log_info("f4 message"); 1455 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1456 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1457 } 1458 1459 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1460 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1461 static const uint8_t f5_length[] = { 0x01, 0x00}; 1462 1463 static void sm_sc_calculate_dhkey(sm_key256_t dhkey){ 1464 #ifdef USE_MBEDTLS_FOR_ECDH 1465 // da * Pb 1466 mbedtls_mpi d; 1467 mbedtls_ecp_point Q; 1468 mbedtls_ecp_point DH; 1469 mbedtls_mpi_init(&d); 1470 mbedtls_ecp_point_init(&Q); 1471 mbedtls_ecp_point_init(&DH); 1472 mbedtls_mpi_read_binary(&d, ec_d, 32); 1473 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 1474 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 1475 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 1476 mbedtls_ecp_mul(&mbedtls_ec_group, &DH, &d, &Q, NULL, NULL); 1477 mbedtls_mpi_write_binary(&DH.X, dhkey, 32); 1478 mbedtls_mpi_free(&d); 1479 mbedtls_ecp_point_free(&Q); 1480 mbedtls_ecp_point_free(&DH); 1481 #endif 1482 log_info("dhkey"); 1483 log_info_hexdump(dhkey, 32); 1484 } 1485 1486 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1487 // calculate DHKEY 1488 sm_key256_t dhkey; 1489 sm_sc_calculate_dhkey(dhkey); 1490 1491 // calculate salt for f5 1492 const uint16_t message_len = 32; 1493 sm_cmac_connection = sm_conn; 1494 memcpy(sm_cmac_sc_buffer, dhkey, message_len); 1495 sm_cmac_general_start(f5_salt, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1496 } 1497 1498 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){ 1499 const uint16_t message_len = 53; 1500 sm_cmac_connection = sm_conn; 1501 1502 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1503 sm_cmac_sc_buffer[0] = 0; 1504 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1505 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1506 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1507 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1508 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1509 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1510 log_info("f5 key"); 1511 log_info_hexdump(t, 16); 1512 log_info("f5 message for MacKey"); 1513 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1514 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1515 } 1516 1517 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1518 sm_key56_t bd_addr_master, bd_addr_slave; 1519 bd_addr_master[0] = setup->sm_m_addr_type; 1520 bd_addr_slave[0] = setup->sm_s_addr_type; 1521 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1522 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1523 if (sm_conn->sm_role){ 1524 // responder 1525 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1526 } else { 1527 // initiator 1528 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1529 } 1530 } 1531 1532 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1533 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1534 const uint16_t message_len = 53; 1535 sm_cmac_connection = sm_conn; 1536 sm_cmac_sc_buffer[0] = 1; 1537 // 1..52 setup before 1538 log_info("f5 key"); 1539 log_info_hexdump(t, 16); 1540 log_info("f5 message for LTK"); 1541 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1542 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1543 } 1544 1545 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1546 f5_ltk(sm_conn, setup->sm_t); 1547 } 1548 1549 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){ 1550 const uint16_t message_len = 65; 1551 sm_cmac_connection = sm_conn; 1552 memcpy(sm_cmac_sc_buffer, n1, 16); 1553 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1554 memcpy(sm_cmac_sc_buffer+32, r, 16); 1555 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1556 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1557 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1558 log_info("f6 key"); 1559 log_info_hexdump(w, 16); 1560 log_info("f6 message"); 1561 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1562 sm_cmac_general_start(w, 65, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1563 } 1564 1565 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1566 // - U is 256 bits 1567 // - V is 256 bits 1568 // - X is 128 bits 1569 // - Y is 128 bits 1570 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){ 1571 const uint16_t message_len = 80; 1572 sm_cmac_connection = sm_conn; 1573 memcpy(sm_cmac_sc_buffer, u, 32); 1574 memcpy(sm_cmac_sc_buffer+32, v, 32); 1575 memcpy(sm_cmac_sc_buffer+64, y, 16); 1576 log_info("g2 key"); 1577 log_info_hexdump(x, 16); 1578 log_info("g2 message"); 1579 log_info_hexdump(sm_cmac_sc_buffer, sizeof(sm_cmac_sc_buffer)); 1580 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1581 } 1582 1583 static void g2_calculate(sm_connection_t * sm_conn) { 1584 // calc Va if numeric comparison 1585 if (sm_conn->sm_role){ 1586 // responder 1587 g2_engine(sm_conn, setup->sm_peer_qx, ec_qx, setup->sm_peer_nonce, setup->sm_local_nonce);; 1588 } else { 1589 // initiator 1590 g2_engine(sm_conn, ec_qx, setup->sm_peer_qx, setup->sm_local_nonce, setup->sm_peer_nonce); 1591 } 1592 } 1593 1594 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1595 uint8_t z = 0; 1596 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1597 // some form of passkey 1598 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1599 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1600 setup->sm_passkey_bit++; 1601 } 1602 f4_engine(sm_conn, ec_qx, setup->sm_peer_qx, setup->sm_local_nonce, z); 1603 } 1604 1605 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1606 uint8_t z = 0; 1607 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1608 // some form of passkey 1609 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1610 // sm_passkey_bit was increased before sending confirm value 1611 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1612 } 1613 f4_engine(sm_conn, setup->sm_peer_qx, ec_qx, setup->sm_peer_nonce, z); 1614 } 1615 1616 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1617 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1618 } 1619 1620 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1621 // calculate DHKCheck 1622 sm_key56_t bd_addr_master, bd_addr_slave; 1623 bd_addr_master[0] = setup->sm_m_addr_type; 1624 bd_addr_slave[0] = setup->sm_s_addr_type; 1625 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1626 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1627 uint8_t iocap_a[3]; 1628 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1629 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1630 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1631 uint8_t iocap_b[3]; 1632 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1633 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1634 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1635 if (sm_conn->sm_role){ 1636 // responder 1637 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); 1638 } else { 1639 // initiator 1640 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); 1641 } 1642 } 1643 1644 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1645 // validate E = f6() 1646 sm_key56_t bd_addr_master, bd_addr_slave; 1647 bd_addr_master[0] = setup->sm_m_addr_type; 1648 bd_addr_slave[0] = setup->sm_s_addr_type; 1649 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1650 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1651 1652 uint8_t iocap_a[3]; 1653 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1654 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1655 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1656 uint8_t iocap_b[3]; 1657 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1658 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1659 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1660 if (sm_conn->sm_role){ 1661 // responder 1662 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); 1663 } else { 1664 // initiator 1665 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); 1666 } 1667 } 1668 #endif 1669 1670 static void sm_load_security_info(sm_connection_t * sm_connection){ 1671 int encryption_key_size; 1672 int authenticated; 1673 int authorized; 1674 1675 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1676 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1677 &encryption_key_size, &authenticated, &authorized); 1678 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1679 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1680 sm_connection->sm_connection_authenticated = authenticated; 1681 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1682 } 1683 1684 static void sm_run(void){ 1685 1686 btstack_linked_list_iterator_t it; 1687 1688 // assert that we can send at least commands 1689 if (!hci_can_send_command_packet_now()) return; 1690 1691 // 1692 // non-connection related behaviour 1693 // 1694 1695 // distributed key generation 1696 switch (dkg_state){ 1697 case DKG_CALC_IRK: 1698 // already busy? 1699 if (sm_aes128_state == SM_AES128_IDLE) { 1700 // IRK = d1(IR, 1, 0) 1701 sm_key_t d1_prime; 1702 sm_d1_d_prime(1, 0, d1_prime); // plaintext 1703 dkg_next_state(); 1704 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1705 return; 1706 } 1707 break; 1708 case DKG_CALC_DHK: 1709 // already busy? 1710 if (sm_aes128_state == SM_AES128_IDLE) { 1711 // DHK = d1(IR, 3, 0) 1712 sm_key_t d1_prime; 1713 sm_d1_d_prime(3, 0, d1_prime); // plaintext 1714 dkg_next_state(); 1715 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1716 return; 1717 } 1718 break; 1719 default: 1720 break; 1721 } 1722 1723 #ifdef USE_MBEDTLS_FOR_ECDH 1724 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 1725 sm_random_start(NULL); 1726 return; 1727 } 1728 #endif 1729 1730 // random address updates 1731 switch (rau_state){ 1732 case RAU_GET_RANDOM: 1733 rau_next_state(); 1734 sm_random_start(NULL); 1735 return; 1736 case RAU_GET_ENC: 1737 // already busy? 1738 if (sm_aes128_state == SM_AES128_IDLE) { 1739 sm_key_t r_prime; 1740 sm_ah_r_prime(sm_random_address, r_prime); 1741 rau_next_state(); 1742 sm_aes128_start(sm_persistent_irk, r_prime, NULL); 1743 return; 1744 } 1745 break; 1746 case RAU_SET_ADDRESS: 1747 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1748 rau_state = RAU_IDLE; 1749 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1750 return; 1751 default: 1752 break; 1753 } 1754 1755 // CMAC 1756 switch (sm_cmac_state){ 1757 case CMAC_CALC_SUBKEYS: 1758 case CMAC_CALC_MI: 1759 case CMAC_CALC_MLAST: 1760 // already busy? 1761 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1762 sm_cmac_handle_aes_engine_ready(); 1763 return; 1764 default: 1765 break; 1766 } 1767 1768 // CSRK Lookup 1769 // -- if csrk lookup ready, find connection that require csrk lookup 1770 if (sm_address_resolution_idle()){ 1771 hci_connections_get_iterator(&it); 1772 while(btstack_linked_list_iterator_has_next(&it)){ 1773 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1774 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1775 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1776 // and start lookup 1777 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); 1778 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1779 break; 1780 } 1781 } 1782 } 1783 1784 // -- if csrk lookup ready, resolved addresses for received addresses 1785 if (sm_address_resolution_idle()) { 1786 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1787 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1788 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1789 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1790 btstack_memory_sm_lookup_entry_free(entry); 1791 } 1792 } 1793 1794 // -- Continue with CSRK device lookup by public or resolvable private address 1795 if (!sm_address_resolution_idle()){ 1796 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_count()); 1797 while (sm_address_resolution_test < le_device_db_count()){ 1798 int addr_type; 1799 bd_addr_t addr; 1800 sm_key_t irk; 1801 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1802 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1803 1804 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1805 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1806 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1807 break; 1808 } 1809 1810 if (sm_address_resolution_addr_type == 0){ 1811 sm_address_resolution_test++; 1812 continue; 1813 } 1814 1815 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1816 1817 log_info("LE Device Lookup: calculate AH"); 1818 log_info_key("IRK", irk); 1819 1820 sm_key_t r_prime; 1821 sm_ah_r_prime(sm_address_resolution_address, r_prime); 1822 sm_address_resolution_ah_calculation_active = 1; 1823 sm_aes128_start(irk, r_prime, sm_address_resolution_context); // keep context 1824 return; 1825 } 1826 1827 if (sm_address_resolution_test >= le_device_db_count()){ 1828 log_info("LE Device Lookup: not found"); 1829 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1830 } 1831 } 1832 1833 1834 // 1835 // active connection handling 1836 // -- use loop to handle next connection if lock on setup context is released 1837 1838 while (1) { 1839 1840 // Find connections that requires setup context and make active if no other is locked 1841 hci_connections_get_iterator(&it); 1842 while(!sm_active_connection && btstack_linked_list_iterator_has_next(&it)){ 1843 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1844 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1845 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 1846 int done = 1; 1847 int err; 1848 switch (sm_connection->sm_engine_state) { 1849 case SM_RESPONDER_SEND_SECURITY_REQUEST: 1850 // send packet if possible, 1851 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 1852 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 1853 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 1854 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1855 } else { 1856 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1857 } 1858 // don't lock sxetup context yet 1859 done = 0; 1860 break; 1861 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 1862 sm_init_setup(sm_connection); 1863 // recover pairing request 1864 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 1865 err = sm_stk_generation_init(sm_connection); 1866 if (err){ 1867 setup->sm_pairing_failed_reason = err; 1868 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1869 break; 1870 } 1871 sm_timeout_start(sm_connection); 1872 // generate random number first, if we need to show passkey 1873 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 1874 sm_connection->sm_engine_state = SM_PH2_GET_RANDOM_TK; 1875 break; 1876 } 1877 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 1878 break; 1879 case SM_INITIATOR_PH0_HAS_LTK: 1880 sm_load_security_info(sm_connection); 1881 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 1882 break; 1883 case SM_RESPONDER_PH0_RECEIVED_LTK: 1884 switch (sm_connection->sm_irk_lookup_state){ 1885 case IRK_LOOKUP_SUCCEEDED:{ 1886 sm_load_security_info(sm_connection); 1887 sm_connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 1888 break; 1889 } 1890 case IRK_LOOKUP_FAILED: 1891 // assume that we don't have a LTK for ediv == 0 and random == null 1892 if (sm_connection->sm_local_ediv == 0 && sm_is_null_random(sm_connection->sm_local_rand)){ 1893 log_info("LTK Request: ediv & random are empty"); 1894 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1895 // TODO: no need to lock context yet -> done = 0; 1896 break; 1897 } 1898 // re-establish previously used LTK using Rand and EDIV 1899 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1900 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1901 // re-establish used key encryption size 1902 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1903 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1904 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1905 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1906 log_info("sm: received ltk request with key size %u, authenticated %u", 1907 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1908 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1909 break; 1910 default: 1911 // just wait until IRK lookup is completed 1912 // don't lock sxetup context yet 1913 done = 0; 1914 break; 1915 } 1916 break; 1917 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 1918 sm_init_setup(sm_connection); 1919 sm_timeout_start(sm_connection); 1920 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 1921 break; 1922 default: 1923 done = 0; 1924 break; 1925 } 1926 if (done){ 1927 sm_active_connection = sm_connection->sm_handle; 1928 log_info("sm: connection 0x%04x locked setup context as %s", sm_active_connection, sm_connection->sm_role ? "responder" : "initiator"); 1929 } 1930 } 1931 1932 // 1933 // active connection handling 1934 // 1935 1936 if (sm_active_connection == 0) return; 1937 1938 // assert that we could send a SM PDU - not needed for all of the following 1939 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 1940 l2cap_request_can_send_fix_channel_now_event(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1941 return; 1942 } 1943 1944 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection); 1945 if (!connection) return; 1946 1947 sm_key_t plaintext; 1948 int key_distribution_flags; 1949 1950 log_info("sm_run: state %u", connection->sm_engine_state); 1951 1952 // responding state 1953 switch (connection->sm_engine_state){ 1954 1955 // general 1956 case SM_GENERAL_SEND_PAIRING_FAILED: { 1957 uint8_t buffer[2]; 1958 buffer[0] = SM_CODE_PAIRING_FAILED; 1959 buffer[1] = setup->sm_pairing_failed_reason; 1960 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 1961 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1962 sm_done_for_handle(connection->sm_handle); 1963 break; 1964 } 1965 1966 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1967 case SM_SC_W2_GET_RANDOM_A: 1968 sm_random_start(connection); 1969 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_A; 1970 break; 1971 case SM_SC_W2_GET_RANDOM_B: 1972 sm_random_start(connection); 1973 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_B; 1974 break; 1975 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 1976 if (!sm_cmac_ready()) break; 1977 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 1978 sm_sc_calculate_local_confirm(connection); 1979 break; 1980 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 1981 if (!sm_cmac_ready()) break; 1982 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 1983 sm_sc_calculate_remote_confirm(connection); 1984 break; 1985 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 1986 if (!sm_cmac_ready()) break; 1987 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 1988 sm_sc_calculate_f6_for_dhkey_check(connection); 1989 break; 1990 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1991 if (!sm_cmac_ready()) break; 1992 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1993 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 1994 break; 1995 case SM_SC_W2_CALCULATE_F5_SALT: 1996 if (!sm_cmac_ready()) break; 1997 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 1998 f5_calculate_salt(connection); 1999 break; 2000 case SM_SC_W2_CALCULATE_F5_MACKEY: 2001 if (!sm_cmac_ready()) break; 2002 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2003 f5_calculate_mackey(connection); 2004 break; 2005 case SM_SC_W2_CALCULATE_F5_LTK: 2006 if (!sm_cmac_ready()) break; 2007 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2008 f5_calculate_ltk(connection); 2009 break; 2010 case SM_SC_W2_CALCULATE_G2: 2011 if (!sm_cmac_ready()) break; 2012 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2013 g2_calculate(connection); 2014 break; 2015 2016 #endif 2017 // initiator side 2018 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2019 sm_key_t peer_ltk_flipped; 2020 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2021 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2022 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2023 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2024 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2025 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2026 return; 2027 } 2028 2029 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2030 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2031 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2032 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2033 sm_timeout_reset(connection); 2034 break; 2035 2036 // responder side 2037 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2038 connection->sm_engine_state = SM_RESPONDER_IDLE; 2039 hci_send_cmd(&hci_le_long_term_key_negative_reply, connection->sm_handle); 2040 sm_done_for_handle(connection->sm_handle); 2041 return; 2042 2043 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2044 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2045 uint8_t buffer[65]; 2046 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2047 // 2048 reverse_256(ec_qx, &buffer[1]); 2049 reverse_256(ec_qy, &buffer[33]); 2050 2051 // stk generation method 2052 // passkey entry: notify app to show passkey or to request passkey 2053 switch (setup->sm_stk_generation_method){ 2054 case JUST_WORKS: 2055 case NK_BOTH_INPUT: 2056 if (connection->sm_role){ 2057 // responder 2058 sm_sc_start_calculating_local_confirm(connection); 2059 } else { 2060 // initiator 2061 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2062 } 2063 break; 2064 case PK_INIT_INPUT: 2065 case PK_RESP_INPUT: 2066 case OK_BOTH_INPUT: 2067 // use random TK for display 2068 memcpy(setup->sm_ra, setup->sm_tk, 16); 2069 memcpy(setup->sm_rb, setup->sm_tk, 16); 2070 setup->sm_passkey_bit = 0; 2071 2072 if (connection->sm_role){ 2073 // responder 2074 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2075 } else { 2076 // initiator 2077 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2078 } 2079 sm_trigger_user_response(connection); 2080 break; 2081 case OOB: 2082 // TODO: implement SC OOB 2083 break; 2084 } 2085 2086 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2087 sm_timeout_reset(connection); 2088 break; 2089 } 2090 case SM_SC_SEND_CONFIRMATION: { 2091 uint8_t buffer[17]; 2092 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2093 reverse_128(setup->sm_local_confirm, &buffer[1]); 2094 if (connection->sm_role){ 2095 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2096 } else { 2097 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2098 } 2099 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2100 sm_timeout_reset(connection); 2101 break; 2102 } 2103 case SM_SC_SEND_PAIRING_RANDOM: { 2104 uint8_t buffer[17]; 2105 buffer[0] = SM_CODE_PAIRING_RANDOM; 2106 reverse_128(setup->sm_local_nonce, &buffer[1]); 2107 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT && setup->sm_passkey_bit < 20){ 2108 if (connection->sm_role){ 2109 // responder 2110 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2111 } else { 2112 // initiator 2113 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2114 } 2115 } else { 2116 if (connection->sm_role){ 2117 // responder 2118 if (setup->sm_stk_generation_method == NK_BOTH_INPUT){ 2119 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2120 } else { 2121 sm_sc_prepare_dhkey_check(connection); 2122 } 2123 } else { 2124 // initiator 2125 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2126 } 2127 } 2128 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2129 sm_timeout_reset(connection); 2130 break; 2131 } 2132 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2133 uint8_t buffer[17]; 2134 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2135 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2136 2137 if (connection->sm_role){ 2138 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2139 } else { 2140 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2141 } 2142 2143 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2144 sm_timeout_reset(connection); 2145 break; 2146 } 2147 2148 #endif 2149 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2150 // echo initiator for now 2151 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2152 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2153 2154 if (setup->sm_use_secure_connections){ 2155 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2156 // skip LTK/EDIV for SC 2157 log_info("sm: dropping encryption information flag"); 2158 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2159 } else { 2160 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2161 } 2162 2163 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); 2164 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); 2165 // update key distribution after ENC was dropped 2166 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2167 2168 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2169 sm_timeout_reset(connection); 2170 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2171 if (!setup->sm_use_secure_connections || setup->sm_stk_generation_method == JUST_WORKS){ 2172 sm_trigger_user_response(connection); 2173 } 2174 return; 2175 2176 case SM_PH2_SEND_PAIRING_RANDOM: { 2177 uint8_t buffer[17]; 2178 buffer[0] = SM_CODE_PAIRING_RANDOM; 2179 reverse_128(setup->sm_local_random, &buffer[1]); 2180 if (connection->sm_role){ 2181 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2182 } else { 2183 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2184 } 2185 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2186 sm_timeout_reset(connection); 2187 break; 2188 } 2189 2190 case SM_PH2_GET_RANDOM_TK: 2191 case SM_PH2_C1_GET_RANDOM_A: 2192 case SM_PH2_C1_GET_RANDOM_B: 2193 case SM_PH3_GET_RANDOM: 2194 case SM_PH3_GET_DIV: 2195 sm_next_responding_state(connection); 2196 sm_random_start(connection); 2197 return; 2198 2199 case SM_PH2_C1_GET_ENC_B: 2200 case SM_PH2_C1_GET_ENC_D: 2201 // already busy? 2202 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2203 sm_next_responding_state(connection); 2204 sm_aes128_start(setup->sm_tk, setup->sm_c1_t3_value, connection); 2205 return; 2206 2207 case SM_PH3_LTK_GET_ENC: 2208 case SM_RESPONDER_PH4_LTK_GET_ENC: 2209 // already busy? 2210 if (sm_aes128_state == SM_AES128_IDLE) { 2211 sm_key_t d_prime; 2212 sm_d1_d_prime(setup->sm_local_div, 0, d_prime); 2213 sm_next_responding_state(connection); 2214 sm_aes128_start(sm_persistent_er, d_prime, connection); 2215 return; 2216 } 2217 break; 2218 2219 case SM_PH3_CSRK_GET_ENC: 2220 // already busy? 2221 if (sm_aes128_state == SM_AES128_IDLE) { 2222 sm_key_t d_prime; 2223 sm_d1_d_prime(setup->sm_local_div, 1, d_prime); 2224 sm_next_responding_state(connection); 2225 sm_aes128_start(sm_persistent_er, d_prime, connection); 2226 return; 2227 } 2228 break; 2229 2230 case SM_PH2_C1_GET_ENC_C: 2231 // already busy? 2232 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2233 // calculate m_confirm using aes128 engine - step 1 2234 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); 2235 sm_next_responding_state(connection); 2236 sm_aes128_start(setup->sm_tk, plaintext, connection); 2237 break; 2238 case SM_PH2_C1_GET_ENC_A: 2239 // already busy? 2240 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2241 // calculate confirm using aes128 engine - step 1 2242 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); 2243 sm_next_responding_state(connection); 2244 sm_aes128_start(setup->sm_tk, plaintext, connection); 2245 break; 2246 case SM_PH2_CALC_STK: 2247 // already busy? 2248 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2249 // calculate STK 2250 if (connection->sm_role){ 2251 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, plaintext); 2252 } else { 2253 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, plaintext); 2254 } 2255 sm_next_responding_state(connection); 2256 sm_aes128_start(setup->sm_tk, plaintext, connection); 2257 break; 2258 case SM_PH3_Y_GET_ENC: 2259 // already busy? 2260 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2261 // PH3B2 - calculate Y from - enc 2262 // Y = dm(DHK, Rand) 2263 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2264 sm_next_responding_state(connection); 2265 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2266 return; 2267 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2268 uint8_t buffer[17]; 2269 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2270 reverse_128(setup->sm_local_confirm, &buffer[1]); 2271 if (connection->sm_role){ 2272 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2273 } else { 2274 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2275 } 2276 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2277 sm_timeout_reset(connection); 2278 return; 2279 } 2280 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2281 sm_key_t stk_flipped; 2282 reverse_128(setup->sm_ltk, stk_flipped); 2283 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2284 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2285 return; 2286 } 2287 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2288 sm_key_t stk_flipped; 2289 reverse_128(setup->sm_ltk, stk_flipped); 2290 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2291 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2292 return; 2293 } 2294 case SM_RESPONDER_PH4_SEND_LTK: { 2295 sm_key_t ltk_flipped; 2296 reverse_128(setup->sm_ltk, ltk_flipped); 2297 connection->sm_engine_state = SM_RESPONDER_IDLE; 2298 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2299 return; 2300 } 2301 case SM_RESPONDER_PH4_Y_GET_ENC: 2302 // already busy? 2303 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2304 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2305 // Y = dm(DHK, Rand) 2306 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2307 sm_next_responding_state(connection); 2308 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2309 return; 2310 2311 case SM_PH3_DISTRIBUTE_KEYS: 2312 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2313 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2314 uint8_t buffer[17]; 2315 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2316 reverse_128(setup->sm_ltk, &buffer[1]); 2317 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2318 sm_timeout_reset(connection); 2319 return; 2320 } 2321 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2322 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2323 uint8_t buffer[11]; 2324 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2325 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2326 reverse_64(setup->sm_local_rand, &buffer[3]); 2327 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2328 sm_timeout_reset(connection); 2329 return; 2330 } 2331 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2332 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2333 uint8_t buffer[17]; 2334 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2335 reverse_128(sm_persistent_irk, &buffer[1]); 2336 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2337 sm_timeout_reset(connection); 2338 return; 2339 } 2340 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2341 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2342 bd_addr_t local_address; 2343 uint8_t buffer[8]; 2344 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2345 gap_advertisements_get_address(&buffer[1], local_address); 2346 reverse_bd_addr(local_address, &buffer[2]); 2347 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2348 sm_timeout_reset(connection); 2349 return; 2350 } 2351 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2352 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2353 2354 // hack to reproduce test runs 2355 if (test_use_fixed_local_csrk){ 2356 memset(setup->sm_local_csrk, 0xcc, 16); 2357 } 2358 2359 uint8_t buffer[17]; 2360 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2361 reverse_128(setup->sm_local_csrk, &buffer[1]); 2362 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2363 sm_timeout_reset(connection); 2364 return; 2365 } 2366 2367 // keys are sent 2368 if (connection->sm_role){ 2369 // slave -> receive master keys if any 2370 if (sm_key_distribution_all_received(connection)){ 2371 sm_key_distribution_handle_all_received(connection); 2372 connection->sm_engine_state = SM_RESPONDER_IDLE; 2373 sm_done_for_handle(connection->sm_handle); 2374 } else { 2375 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2376 } 2377 } else { 2378 // master -> all done 2379 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2380 sm_done_for_handle(connection->sm_handle); 2381 } 2382 break; 2383 2384 default: 2385 break; 2386 } 2387 2388 // check again if active connection was released 2389 if (sm_active_connection) break; 2390 } 2391 } 2392 2393 // note: aes engine is ready as we just got the aes result 2394 static void sm_handle_encryption_result(uint8_t * data){ 2395 2396 sm_aes128_state = SM_AES128_IDLE; 2397 2398 if (sm_address_resolution_ah_calculation_active){ 2399 sm_address_resolution_ah_calculation_active = 0; 2400 // compare calulated address against connecting device 2401 uint8_t hash[3]; 2402 reverse_24(data, hash); 2403 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2404 log_info("LE Device Lookup: matched resolvable private address"); 2405 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2406 return; 2407 } 2408 // no match, try next 2409 sm_address_resolution_test++; 2410 return; 2411 } 2412 2413 switch (dkg_state){ 2414 case DKG_W4_IRK: 2415 reverse_128(data, sm_persistent_irk); 2416 log_info_key("irk", sm_persistent_irk); 2417 dkg_next_state(); 2418 return; 2419 case DKG_W4_DHK: 2420 reverse_128(data, sm_persistent_dhk); 2421 log_info_key("dhk", sm_persistent_dhk); 2422 dkg_next_state(); 2423 // SM Init Finished 2424 return; 2425 default: 2426 break; 2427 } 2428 2429 switch (rau_state){ 2430 case RAU_W4_ENC: 2431 reverse_24(data, &sm_random_address[3]); 2432 rau_next_state(); 2433 return; 2434 default: 2435 break; 2436 } 2437 2438 switch (sm_cmac_state){ 2439 case CMAC_W4_SUBKEYS: 2440 case CMAC_W4_MI: 2441 case CMAC_W4_MLAST: 2442 { 2443 sm_key_t t; 2444 reverse_128(data, t); 2445 sm_cmac_handle_encryption_result(t); 2446 } 2447 return; 2448 default: 2449 break; 2450 } 2451 2452 // retrieve sm_connection provided to sm_aes128_start_encryption 2453 sm_connection_t * connection = (sm_connection_t*) sm_aes128_context; 2454 if (!connection) return; 2455 switch (connection->sm_engine_state){ 2456 case SM_PH2_C1_W4_ENC_A: 2457 case SM_PH2_C1_W4_ENC_C: 2458 { 2459 sm_key_t t2; 2460 reverse_128(data, t2); 2461 sm_c1_t3(t2, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2462 } 2463 sm_next_responding_state(connection); 2464 return; 2465 case SM_PH2_C1_W4_ENC_B: 2466 reverse_128(data, setup->sm_local_confirm); 2467 log_info_key("c1!", setup->sm_local_confirm); 2468 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2469 return; 2470 case SM_PH2_C1_W4_ENC_D: 2471 { 2472 sm_key_t peer_confirm_test; 2473 reverse_128(data, peer_confirm_test); 2474 log_info_key("c1!", peer_confirm_test); 2475 if (memcmp(setup->sm_peer_confirm, peer_confirm_test, 16) != 0){ 2476 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2477 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2478 return; 2479 } 2480 if (connection->sm_role){ 2481 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2482 } else { 2483 connection->sm_engine_state = SM_PH2_CALC_STK; 2484 } 2485 } 2486 return; 2487 case SM_PH2_W4_STK: 2488 reverse_128(data, setup->sm_ltk); 2489 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2490 log_info_key("stk", setup->sm_ltk); 2491 if (connection->sm_role){ 2492 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2493 } else { 2494 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2495 } 2496 return; 2497 case SM_PH3_Y_W4_ENC:{ 2498 sm_key_t y128; 2499 reverse_128(data, y128); 2500 setup->sm_local_y = big_endian_read_16(y128, 14); 2501 log_info_hex16("y", setup->sm_local_y); 2502 // PH3B3 - calculate EDIV 2503 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2504 log_info_hex16("ediv", setup->sm_local_ediv); 2505 // PH3B4 - calculate LTK - enc 2506 // LTK = d1(ER, DIV, 0)) 2507 connection->sm_engine_state = SM_PH3_LTK_GET_ENC; 2508 return; 2509 } 2510 case SM_RESPONDER_PH4_Y_W4_ENC:{ 2511 sm_key_t y128; 2512 reverse_128(data, y128); 2513 setup->sm_local_y = big_endian_read_16(y128, 14); 2514 log_info_hex16("y", setup->sm_local_y); 2515 2516 // PH3B3 - calculate DIV 2517 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2518 log_info_hex16("ediv", setup->sm_local_ediv); 2519 // PH3B4 - calculate LTK - enc 2520 // LTK = d1(ER, DIV, 0)) 2521 connection->sm_engine_state = SM_RESPONDER_PH4_LTK_GET_ENC; 2522 return; 2523 } 2524 case SM_PH3_LTK_W4_ENC: 2525 reverse_128(data, setup->sm_ltk); 2526 log_info_key("ltk", setup->sm_ltk); 2527 // calc CSRK next 2528 connection->sm_engine_state = SM_PH3_CSRK_GET_ENC; 2529 return; 2530 case SM_PH3_CSRK_W4_ENC: 2531 reverse_128(data, setup->sm_local_csrk); 2532 log_info_key("csrk", setup->sm_local_csrk); 2533 if (setup->sm_key_distribution_send_set){ 2534 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2535 } else { 2536 // no keys to send, just continue 2537 if (connection->sm_role){ 2538 // slave -> receive master keys 2539 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2540 } else { 2541 // master -> all done 2542 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2543 sm_done_for_handle(connection->sm_handle); 2544 } 2545 } 2546 return; 2547 case SM_RESPONDER_PH4_LTK_W4_ENC: 2548 reverse_128(data, setup->sm_ltk); 2549 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2550 log_info_key("ltk", setup->sm_ltk); 2551 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK; 2552 return; 2553 default: 2554 break; 2555 } 2556 } 2557 2558 #ifdef USE_MBEDTLS_FOR_ECDH 2559 2560 static int sm_generate_f_rng(void * context, unsigned char * buffer, size_t size){ 2561 int offset = setup->sm_passkey_bit; 2562 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, offset); 2563 while (size) { 2564 if (offset < 32){ 2565 *buffer++ = setup->sm_peer_qx[offset++]; 2566 } else { 2567 *buffer++ = setup->sm_peer_qx[offset++ - 32]; 2568 } 2569 size--; 2570 } 2571 setup->sm_passkey_bit = offset; 2572 return 0; 2573 } 2574 #endif 2575 2576 // note: random generator is ready. this doesn NOT imply that aes engine is unused! 2577 static void sm_handle_random_result(uint8_t * data){ 2578 2579 #ifdef USE_MBEDTLS_FOR_ECDH 2580 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 2581 int num_bytes = setup->sm_passkey_bit; 2582 if (num_bytes < 32){ 2583 memcpy(&setup->sm_peer_qx[num_bytes], data, 8); 2584 } else { 2585 memcpy(&setup->sm_peer_qx[num_bytes-32], data, 8); 2586 } 2587 num_bytes += 8; 2588 setup->sm_passkey_bit = num_bytes; 2589 2590 if (num_bytes >= 64){ 2591 // generate EC key 2592 setup->sm_passkey_bit = 0; 2593 mbedtls_mpi d; 2594 mbedtls_ecp_point P; 2595 mbedtls_mpi_init(&d); 2596 mbedtls_ecp_point_init(&P); 2597 int res = mbedtls_ecp_gen_keypair(&mbedtls_ec_group, &d, &P, &sm_generate_f_rng, NULL); 2598 log_info("gen keypair %x", res); 2599 mbedtls_mpi_write_binary(&P.X, ec_qx, 32); 2600 mbedtls_mpi_write_binary(&P.Y, ec_qy, 32); 2601 mbedtls_mpi_write_binary(&d, ec_d, 32); 2602 mbedtls_ecp_point_free(&P); 2603 mbedtls_mpi_free(&d); 2604 ec_key_generation_state = EC_KEY_GENERATION_DONE; 2605 sm_log_ec_keypair(); 2606 2607 #if 0 2608 printf("test dhkey check\n"); 2609 sm_key256_t dhkey; 2610 memcpy(setup->sm_peer_qx, ec_qx, 32); 2611 memcpy(setup->sm_peer_qy, ec_qy, 32); 2612 sm_sc_calculate_dhkey(dhkey); 2613 #endif 2614 2615 } 2616 } 2617 #endif 2618 2619 switch (rau_state){ 2620 case RAU_W4_RANDOM: 2621 // non-resolvable vs. resolvable 2622 switch (gap_random_adress_type){ 2623 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2624 // resolvable: use random as prand and calc address hash 2625 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2626 memcpy(sm_random_address, data, 3); 2627 sm_random_address[0] &= 0x3f; 2628 sm_random_address[0] |= 0x40; 2629 rau_state = RAU_GET_ENC; 2630 break; 2631 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2632 default: 2633 // "The two most significant bits of the address shall be equal to ‘0’"" 2634 memcpy(sm_random_address, data, 6); 2635 sm_random_address[0] &= 0x3f; 2636 rau_state = RAU_SET_ADDRESS; 2637 break; 2638 } 2639 return; 2640 default: 2641 break; 2642 } 2643 2644 // retrieve sm_connection provided to sm_random_start 2645 sm_connection_t * connection = (sm_connection_t *) sm_random_context; 2646 if (!connection) return; 2647 switch (connection->sm_engine_state){ 2648 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2649 case SM_SC_W4_GET_RANDOM_A: 2650 memcpy(&setup->sm_local_nonce[0], data, 8); 2651 connection->sm_engine_state = SM_SC_W2_GET_RANDOM_B; 2652 break; 2653 case SM_SC_W4_GET_RANDOM_B: 2654 memcpy(&setup->sm_local_nonce[8], data, 8); 2655 // initiator & jw/nc -> send pairing random 2656 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2657 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2658 break; 2659 } else { 2660 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2661 } 2662 break; 2663 #endif 2664 2665 case SM_PH2_W4_RANDOM_TK: 2666 { 2667 // map random to 0-999999 without speding much cycles on a modulus operation 2668 uint32_t tk = little_endian_read_32(data,0); 2669 tk = tk & 0xfffff; // 1048575 2670 if (tk >= 999999){ 2671 tk = tk - 999999; 2672 } 2673 sm_reset_tk(); 2674 big_endian_store_32(setup->sm_tk, 12, tk); 2675 if (connection->sm_role){ 2676 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2677 } else { 2678 if (setup->sm_use_secure_connections){ 2679 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 2680 } else { 2681 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2682 sm_trigger_user_response(connection); 2683 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2684 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2685 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 2686 } 2687 } 2688 } 2689 return; 2690 } 2691 case SM_PH2_C1_W4_RANDOM_A: 2692 memcpy(&setup->sm_local_random[0], data, 8); // random endinaness 2693 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_B; 2694 return; 2695 case SM_PH2_C1_W4_RANDOM_B: 2696 memcpy(&setup->sm_local_random[8], data, 8); // random endinaness 2697 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2698 return; 2699 case SM_PH3_W4_RANDOM: 2700 reverse_64(data, setup->sm_local_rand); 2701 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2702 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2703 // no db for authenticated flag hack: store flag in bit 4 of LSB 2704 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2705 connection->sm_engine_state = SM_PH3_GET_DIV; 2706 return; 2707 case SM_PH3_W4_DIV: 2708 // use 16 bit from random value as div 2709 setup->sm_local_div = big_endian_read_16(data, 0); 2710 log_info_hex16("div", setup->sm_local_div); 2711 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2712 return; 2713 default: 2714 break; 2715 } 2716 } 2717 2718 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2719 2720 sm_connection_t * sm_conn; 2721 hci_con_handle_t con_handle; 2722 2723 switch (packet_type) { 2724 2725 case HCI_EVENT_PACKET: 2726 switch (hci_event_packet_get_type(packet)) { 2727 2728 case BTSTACK_EVENT_STATE: 2729 // bt stack activated, get started 2730 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2731 log_info("HCI Working!"); 2732 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 2733 rau_state = RAU_IDLE; 2734 #ifdef USE_MBEDTLS_FOR_ECDH 2735 if (!sm_have_ec_keypair){ 2736 setup->sm_passkey_bit = 0; 2737 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 2738 } 2739 #endif 2740 sm_run(); 2741 } 2742 break; 2743 2744 case HCI_EVENT_LE_META: 2745 switch (packet[2]) { 2746 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2747 2748 log_info("sm: connected"); 2749 2750 if (packet[3]) return; // connection failed 2751 2752 con_handle = little_endian_read_16(packet, 4); 2753 sm_conn = sm_get_connection_for_handle(con_handle); 2754 if (!sm_conn) break; 2755 2756 sm_conn->sm_handle = con_handle; 2757 sm_conn->sm_role = packet[6]; 2758 sm_conn->sm_peer_addr_type = packet[7]; 2759 reverse_bd_addr(&packet[8], 2760 sm_conn->sm_peer_address); 2761 2762 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2763 2764 // reset security properties 2765 sm_conn->sm_connection_encrypted = 0; 2766 sm_conn->sm_connection_authenticated = 0; 2767 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2768 sm_conn->sm_le_db_index = -1; 2769 2770 // prepare CSRK lookup (does not involve setup) 2771 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2772 2773 // just connected -> everything else happens in sm_run() 2774 if (sm_conn->sm_role){ 2775 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2776 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2777 if (sm_slave_request_security) { 2778 // request security if requested by app 2779 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2780 } else { 2781 // otherwise, wait for pairing request 2782 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2783 } 2784 } 2785 break; 2786 } else { 2787 // master 2788 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2789 } 2790 break; 2791 2792 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2793 con_handle = little_endian_read_16(packet, 3); 2794 sm_conn = sm_get_connection_for_handle(con_handle); 2795 if (!sm_conn) break; 2796 2797 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2798 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2799 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2800 break; 2801 } 2802 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 2803 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2804 break; 2805 } 2806 2807 // store rand and ediv 2808 reverse_64(&packet[5], sm_conn->sm_local_rand); 2809 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2810 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK; 2811 break; 2812 2813 default: 2814 break; 2815 } 2816 break; 2817 2818 case HCI_EVENT_ENCRYPTION_CHANGE: 2819 con_handle = little_endian_read_16(packet, 3); 2820 sm_conn = sm_get_connection_for_handle(con_handle); 2821 if (!sm_conn) break; 2822 2823 sm_conn->sm_connection_encrypted = packet[5]; 2824 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 2825 sm_conn->sm_actual_encryption_key_size); 2826 log_info("event handler, state %u", sm_conn->sm_engine_state); 2827 if (!sm_conn->sm_connection_encrypted) break; 2828 // continue if part of initial pairing 2829 switch (sm_conn->sm_engine_state){ 2830 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2831 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2832 sm_done_for_handle(sm_conn->sm_handle); 2833 break; 2834 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2835 if (sm_conn->sm_role){ 2836 // slave 2837 if (setup->sm_use_secure_connections){ 2838 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2839 } else { 2840 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2841 } 2842 } else { 2843 // master 2844 if (sm_key_distribution_all_received(sm_conn)){ 2845 // skip receiving keys as there are none 2846 sm_key_distribution_handle_all_received(sm_conn); 2847 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2848 } else { 2849 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2850 } 2851 } 2852 break; 2853 default: 2854 break; 2855 } 2856 break; 2857 2858 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 2859 con_handle = little_endian_read_16(packet, 3); 2860 sm_conn = sm_get_connection_for_handle(con_handle); 2861 if (!sm_conn) break; 2862 2863 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 2864 log_info("event handler, state %u", sm_conn->sm_engine_state); 2865 // continue if part of initial pairing 2866 switch (sm_conn->sm_engine_state){ 2867 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2868 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2869 sm_done_for_handle(sm_conn->sm_handle); 2870 break; 2871 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2872 if (sm_conn->sm_role){ 2873 // slave 2874 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2875 } else { 2876 // master 2877 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2878 } 2879 break; 2880 default: 2881 break; 2882 } 2883 break; 2884 2885 2886 case HCI_EVENT_DISCONNECTION_COMPLETE: 2887 con_handle = little_endian_read_16(packet, 3); 2888 sm_done_for_handle(con_handle); 2889 sm_conn = sm_get_connection_for_handle(con_handle); 2890 if (!sm_conn) break; 2891 2892 // delete stored bonding on disconnect with authentication failure in ph0 2893 if (sm_conn->sm_role == 0 2894 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 2895 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 2896 le_device_db_remove(sm_conn->sm_le_db_index); 2897 } 2898 2899 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 2900 sm_conn->sm_handle = 0; 2901 break; 2902 2903 case HCI_EVENT_COMMAND_COMPLETE: 2904 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 2905 sm_handle_encryption_result(&packet[6]); 2906 break; 2907 } 2908 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 2909 sm_handle_random_result(&packet[6]); 2910 break; 2911 } 2912 break; 2913 default: 2914 break; 2915 } 2916 break; 2917 default: 2918 break; 2919 } 2920 2921 sm_run(); 2922 } 2923 2924 static inline int sm_calc_actual_encryption_key_size(int other){ 2925 if (other < sm_min_encryption_key_size) return 0; 2926 if (other < sm_max_encryption_key_size) return other; 2927 return sm_max_encryption_key_size; 2928 } 2929 2930 2931 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 2932 switch (method){ 2933 case JUST_WORKS: 2934 case NK_BOTH_INPUT: 2935 return 1; 2936 default: 2937 return 0; 2938 } 2939 } 2940 // responder 2941 2942 static int sm_passkey_used(stk_generation_method_t method){ 2943 switch (method){ 2944 case PK_RESP_INPUT: 2945 return 1; 2946 default: 2947 return 0; 2948 } 2949 } 2950 2951 /** 2952 * @return ok 2953 */ 2954 static int sm_validate_stk_generation_method(void){ 2955 // check if STK generation method is acceptable by client 2956 switch (setup->sm_stk_generation_method){ 2957 case JUST_WORKS: 2958 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 2959 case PK_RESP_INPUT: 2960 case PK_INIT_INPUT: 2961 case OK_BOTH_INPUT: 2962 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 2963 case OOB: 2964 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 2965 case NK_BOTH_INPUT: 2966 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 2967 return 1; 2968 default: 2969 return 0; 2970 } 2971 } 2972 2973 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 2974 2975 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 2976 sm_run(); 2977 } 2978 2979 if (packet_type != SM_DATA_PACKET) return; 2980 2981 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 2982 if (!sm_conn) return; 2983 2984 if (packet[0] == SM_CODE_PAIRING_FAILED){ 2985 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2986 return; 2987 } 2988 2989 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, packet[0]); 2990 2991 int err; 2992 2993 switch (sm_conn->sm_engine_state){ 2994 2995 // a sm timeout requries a new physical connection 2996 case SM_GENERAL_TIMEOUT: 2997 return; 2998 2999 // Initiator 3000 case SM_INITIATOR_CONNECTED: 3001 if ((packet[0] != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3002 sm_pdu_received_in_wrong_state(sm_conn); 3003 break; 3004 } 3005 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 3006 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3007 break; 3008 } 3009 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 3010 uint16_t ediv; 3011 sm_key_t ltk; 3012 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3013 if (!sm_is_null_key(ltk) || ediv){ 3014 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3015 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3016 } else { 3017 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3018 } 3019 break; 3020 } 3021 // otherwise, store security request 3022 sm_conn->sm_security_request_received = 1; 3023 break; 3024 3025 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3026 if (packet[0] != SM_CODE_PAIRING_RESPONSE){ 3027 sm_pdu_received_in_wrong_state(sm_conn); 3028 break; 3029 } 3030 // store pairing request 3031 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3032 err = sm_stk_generation_init(sm_conn); 3033 if (err){ 3034 setup->sm_pairing_failed_reason = err; 3035 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3036 break; 3037 } 3038 3039 // generate random number first, if we need to show passkey 3040 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3041 sm_conn->sm_engine_state = SM_PH2_GET_RANDOM_TK; 3042 break; 3043 } 3044 3045 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3046 if (setup->sm_use_secure_connections){ 3047 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3048 if (setup->sm_stk_generation_method == JUST_WORKS){ 3049 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3050 sm_trigger_user_response(sm_conn); 3051 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3052 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3053 } 3054 } else { 3055 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3056 } 3057 break; 3058 } 3059 #endif 3060 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3061 sm_trigger_user_response(sm_conn); 3062 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3063 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3064 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3065 } 3066 break; 3067 3068 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3069 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3070 sm_pdu_received_in_wrong_state(sm_conn); 3071 break; 3072 } 3073 3074 // store s_confirm 3075 reverse_128(&packet[1], setup->sm_peer_confirm); 3076 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3077 break; 3078 3079 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3080 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3081 sm_pdu_received_in_wrong_state(sm_conn); 3082 break;; 3083 } 3084 3085 // received random value 3086 reverse_128(&packet[1], setup->sm_peer_random); 3087 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3088 break; 3089 3090 // Responder 3091 case SM_RESPONDER_IDLE: 3092 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3093 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3094 if (packet[0] != SM_CODE_PAIRING_REQUEST){ 3095 sm_pdu_received_in_wrong_state(sm_conn); 3096 break;; 3097 } 3098 3099 // store pairing request 3100 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3101 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3102 break; 3103 3104 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3105 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3106 if (packet[0] != SM_CODE_PAIRING_PUBLIC_KEY){ 3107 sm_pdu_received_in_wrong_state(sm_conn); 3108 break; 3109 } 3110 3111 // store public key for DH Key calculation 3112 reverse_256(&packet[01], setup->sm_peer_qx); 3113 reverse_256(&packet[33], setup->sm_peer_qy); 3114 3115 #ifdef USE_MBEDTLS_FOR_ECDH 3116 // validate public key 3117 mbedtls_ecp_point Q; 3118 mbedtls_ecp_point_init( &Q ); 3119 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 3120 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 3121 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 3122 err = mbedtls_ecp_check_pubkey(&mbedtls_ec_group, &Q); 3123 mbedtls_ecp_point_free( & Q); 3124 if (err){ 3125 log_error("sm: peer public key invalid %x", err); 3126 // uses "unspecified reason", there is no "public key invalid" error code 3127 sm_pdu_received_in_wrong_state(sm_conn); 3128 break; 3129 } 3130 3131 #endif 3132 if (sm_conn->sm_role){ 3133 // responder 3134 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3135 } else { 3136 // initiator 3137 // stk generation method 3138 // passkey entry: notify app to show passkey or to request passkey 3139 switch (setup->sm_stk_generation_method){ 3140 case JUST_WORKS: 3141 case NK_BOTH_INPUT: 3142 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3143 break; 3144 case PK_RESP_INPUT: 3145 sm_sc_start_calculating_local_confirm(sm_conn); 3146 break; 3147 case PK_INIT_INPUT: 3148 case OK_BOTH_INPUT: 3149 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3150 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3151 break; 3152 } 3153 sm_sc_start_calculating_local_confirm(sm_conn); 3154 break; 3155 case OOB: 3156 // TODO: implement SC OOB 3157 break; 3158 } 3159 } 3160 break; 3161 3162 case SM_SC_W4_CONFIRMATION: 3163 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3164 sm_pdu_received_in_wrong_state(sm_conn); 3165 break; 3166 } 3167 // received confirm value 3168 reverse_128(&packet[1], setup->sm_peer_confirm); 3169 3170 if (sm_conn->sm_role){ 3171 // responder 3172 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3173 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3174 // still waiting for passkey 3175 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3176 break; 3177 } 3178 } 3179 sm_sc_start_calculating_local_confirm(sm_conn); 3180 } else { 3181 // initiator 3182 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3183 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3184 } else { 3185 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3186 } 3187 } 3188 break; 3189 3190 case SM_SC_W4_PAIRING_RANDOM: 3191 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3192 sm_pdu_received_in_wrong_state(sm_conn); 3193 break; 3194 } 3195 3196 // received random value 3197 reverse_128(&packet[1], setup->sm_peer_nonce); 3198 3199 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3200 // only check for JUST WORK/NC in initiator role AND passkey entry 3201 int passkey_entry = sm_passkey_used(setup->sm_stk_generation_method); 3202 if (sm_conn->sm_role || passkey_entry) { 3203 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3204 } 3205 3206 sm_sc_state_after_receiving_random(sm_conn); 3207 break; 3208 3209 case SM_SC_W2_CALCULATE_G2: 3210 case SM_SC_W4_CALCULATE_G2: 3211 case SM_SC_W2_CALCULATE_F5_SALT: 3212 case SM_SC_W4_CALCULATE_F5_SALT: 3213 case SM_SC_W2_CALCULATE_F5_MACKEY: 3214 case SM_SC_W4_CALCULATE_F5_MACKEY: 3215 case SM_SC_W2_CALCULATE_F5_LTK: 3216 case SM_SC_W4_CALCULATE_F5_LTK: 3217 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3218 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3219 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3220 if (packet[0] != SM_CODE_PAIRING_DHKEY_CHECK){ 3221 sm_pdu_received_in_wrong_state(sm_conn); 3222 break; 3223 } 3224 // store DHKey Check 3225 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3226 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3227 3228 // have we been only waiting for dhkey check command? 3229 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3230 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3231 } 3232 break; 3233 #endif 3234 3235 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3236 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3237 sm_pdu_received_in_wrong_state(sm_conn); 3238 break; 3239 } 3240 3241 // received confirm value 3242 reverse_128(&packet[1], setup->sm_peer_confirm); 3243 3244 // notify client to hide shown passkey 3245 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3246 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3247 } 3248 3249 // handle user cancel pairing? 3250 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3251 setup->sm_pairing_failed_reason = SM_REASON_PASSKEYT_ENTRY_FAILED; 3252 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3253 break; 3254 } 3255 3256 // wait for user action? 3257 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3258 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3259 break; 3260 } 3261 3262 // calculate and send local_confirm 3263 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3264 break; 3265 3266 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3267 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3268 sm_pdu_received_in_wrong_state(sm_conn); 3269 break;; 3270 } 3271 3272 // received random value 3273 reverse_128(&packet[1], setup->sm_peer_random); 3274 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3275 break; 3276 3277 case SM_PH3_RECEIVE_KEYS: 3278 switch(packet[0]){ 3279 case SM_CODE_ENCRYPTION_INFORMATION: 3280 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3281 reverse_128(&packet[1], setup->sm_peer_ltk); 3282 break; 3283 3284 case SM_CODE_MASTER_IDENTIFICATION: 3285 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3286 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3287 reverse_64(&packet[3], setup->sm_peer_rand); 3288 break; 3289 3290 case SM_CODE_IDENTITY_INFORMATION: 3291 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3292 reverse_128(&packet[1], setup->sm_peer_irk); 3293 break; 3294 3295 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3296 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3297 setup->sm_peer_addr_type = packet[1]; 3298 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3299 break; 3300 3301 case SM_CODE_SIGNING_INFORMATION: 3302 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3303 reverse_128(&packet[1], setup->sm_peer_csrk); 3304 break; 3305 default: 3306 // Unexpected PDU 3307 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3308 break; 3309 } 3310 // done with key distribution? 3311 if (sm_key_distribution_all_received(sm_conn)){ 3312 3313 sm_key_distribution_handle_all_received(sm_conn); 3314 3315 if (sm_conn->sm_role){ 3316 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3317 sm_done_for_handle(sm_conn->sm_handle); 3318 } else { 3319 if (setup->sm_use_secure_connections){ 3320 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3321 } else { 3322 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3323 } 3324 } 3325 } 3326 break; 3327 default: 3328 // Unexpected PDU 3329 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3330 break; 3331 } 3332 3333 // try to send preparared packet 3334 sm_run(); 3335 } 3336 3337 // Security Manager Client API 3338 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data)){ 3339 sm_get_oob_data = get_oob_data_callback; 3340 } 3341 3342 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3343 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3344 } 3345 3346 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3347 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3348 } 3349 3350 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3351 sm_min_encryption_key_size = min_size; 3352 sm_max_encryption_key_size = max_size; 3353 } 3354 3355 void sm_set_authentication_requirements(uint8_t auth_req){ 3356 sm_auth_req = auth_req; 3357 } 3358 3359 void sm_set_io_capabilities(io_capability_t io_capability){ 3360 sm_io_capabilities = io_capability; 3361 } 3362 3363 void sm_set_request_security(int enable){ 3364 sm_slave_request_security = enable; 3365 } 3366 3367 void sm_set_er(sm_key_t er){ 3368 memcpy(sm_persistent_er, er, 16); 3369 } 3370 3371 void sm_set_ir(sm_key_t ir){ 3372 memcpy(sm_persistent_ir, ir, 16); 3373 } 3374 3375 // Testing support only 3376 void sm_test_set_irk(sm_key_t irk){ 3377 memcpy(sm_persistent_irk, irk, 16); 3378 sm_persistent_irk_ready = 1; 3379 } 3380 3381 void sm_test_use_fixed_local_csrk(void){ 3382 test_use_fixed_local_csrk = 1; 3383 } 3384 3385 void sm_init(void){ 3386 // set some (BTstack default) ER and IR 3387 int i; 3388 sm_key_t er; 3389 sm_key_t ir; 3390 for (i=0;i<16;i++){ 3391 er[i] = 0x30 + i; 3392 ir[i] = 0x90 + i; 3393 } 3394 sm_set_er(er); 3395 sm_set_ir(ir); 3396 // defaults 3397 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3398 | SM_STK_GENERATION_METHOD_OOB 3399 | SM_STK_GENERATION_METHOD_PASSKEY 3400 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3401 3402 sm_max_encryption_key_size = 16; 3403 sm_min_encryption_key_size = 7; 3404 3405 sm_cmac_state = CMAC_IDLE; 3406 dkg_state = DKG_W4_WORKING; 3407 rau_state = RAU_W4_WORKING; 3408 sm_aes128_state = SM_AES128_IDLE; 3409 sm_address_resolution_test = -1; // no private address to resolve yet 3410 sm_address_resolution_ah_calculation_active = 0; 3411 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3412 sm_address_resolution_general_queue = NULL; 3413 3414 gap_random_adress_update_period = 15 * 60 * 1000L; 3415 3416 sm_active_connection = 0; 3417 3418 test_use_fixed_local_csrk = 0; 3419 3420 // register for HCI Events from HCI 3421 hci_event_callback_registration.callback = &sm_event_packet_handler; 3422 hci_add_event_handler(&hci_event_callback_registration); 3423 3424 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3425 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3426 3427 #ifdef USE_MBEDTLS_FOR_ECDH 3428 ec_key_generation_state = EC_KEY_GENERATION_IDLE; 3429 3430 #ifndef HAVE_MALLOC 3431 sm_mbedtls_allocator_init(mbedtls_memory_buffer, sizeof(mbedtls_memory_buffer)); 3432 #endif 3433 mbedtls_ecp_group_init(&mbedtls_ec_group); 3434 mbedtls_ecp_group_load(&mbedtls_ec_group, MBEDTLS_ECP_DP_SECP256R1); 3435 3436 #if 0 3437 // test 3438 sm_test_use_fixed_ec_keypair(); 3439 if (sm_have_ec_keypair){ 3440 printf("test dhkey check\n"); 3441 sm_key256_t dhkey; 3442 memcpy(setup->sm_peer_qx, ec_qx, 32); 3443 memcpy(setup->sm_peer_qy, ec_qy, 32); 3444 sm_sc_calculate_dhkey(dhkey); 3445 } 3446 #endif 3447 #endif 3448 } 3449 3450 void sm_use_fixed_ec_keypair(uint8_t * qx, uint8_t * qy, uint8_t * d){ 3451 memcpy(ec_qx, qx, 32); 3452 memcpy(ec_qy, qy, 32); 3453 memcpy(ec_d, d, 32); 3454 sm_have_ec_keypair = 1; 3455 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3456 } 3457 3458 void sm_test_use_fixed_ec_keypair(void){ 3459 #ifdef USE_MBEDTLS_FOR_ECDH 3460 // use test keypair from spec 3461 mbedtls_mpi x; 3462 mbedtls_mpi_init(&x); 3463 mbedtls_mpi_read_string( &x, 16, "3f49f6d4a3c55f3874c9b3e3d2103f504aff607beb40b7995899b8a6cd3c1abd"); 3464 mbedtls_mpi_write_binary(&x, ec_d, 32); 3465 mbedtls_mpi_read_string( &x, 16, "20b003d2f297be2c5e2c83a7e9f9a5b9eff49111acf4fddbcc0301480e359de6"); 3466 mbedtls_mpi_write_binary(&x, ec_qx, 32); 3467 mbedtls_mpi_read_string( &x, 16, "dc809c49652aeb6d63329abf5a52155c766345c28fed3024741c8ed01589d28b"); 3468 mbedtls_mpi_write_binary(&x, ec_qy, 32); 3469 mbedtls_mpi_free(&x); 3470 #endif 3471 sm_have_ec_keypair = 1; 3472 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3473 } 3474 3475 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3476 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3477 if (!hci_con) return NULL; 3478 return &hci_con->sm_connection; 3479 } 3480 3481 // @returns 0 if not encrypted, 7-16 otherwise 3482 int sm_encryption_key_size(hci_con_handle_t con_handle){ 3483 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3484 if (!sm_conn) return 0; // wrong connection 3485 if (!sm_conn->sm_connection_encrypted) return 0; 3486 return sm_conn->sm_actual_encryption_key_size; 3487 } 3488 3489 int sm_authenticated(hci_con_handle_t con_handle){ 3490 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3491 if (!sm_conn) return 0; // wrong connection 3492 if (!sm_conn->sm_connection_encrypted) return 0; // unencrypted connection cannot be authenticated 3493 return sm_conn->sm_connection_authenticated; 3494 } 3495 3496 authorization_state_t sm_authorization_state(hci_con_handle_t con_handle){ 3497 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3498 if (!sm_conn) return AUTHORIZATION_UNKNOWN; // wrong connection 3499 if (!sm_conn->sm_connection_encrypted) return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized 3500 if (!sm_conn->sm_connection_authenticated) return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized 3501 return sm_conn->sm_connection_authorization_state; 3502 } 3503 3504 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3505 switch (sm_conn->sm_engine_state){ 3506 case SM_GENERAL_IDLE: 3507 case SM_RESPONDER_IDLE: 3508 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3509 sm_run(); 3510 break; 3511 default: 3512 break; 3513 } 3514 } 3515 3516 /** 3517 * @brief Trigger Security Request 3518 */ 3519 void sm_send_security_request(hci_con_handle_t con_handle){ 3520 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3521 if (!sm_conn) return; 3522 sm_send_security_request_for_connection(sm_conn); 3523 } 3524 3525 // request pairing 3526 void sm_request_pairing(hci_con_handle_t con_handle){ 3527 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3528 if (!sm_conn) return; // wrong connection 3529 3530 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3531 if (sm_conn->sm_role){ 3532 sm_send_security_request_for_connection(sm_conn); 3533 } else { 3534 // used as a trigger to start central/master/initiator security procedures 3535 uint16_t ediv; 3536 sm_key_t ltk; 3537 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3538 switch (sm_conn->sm_irk_lookup_state){ 3539 case IRK_LOOKUP_FAILED: 3540 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3541 break; 3542 case IRK_LOOKUP_SUCCEEDED: 3543 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3544 if (!sm_is_null_key(ltk) || ediv){ 3545 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3546 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3547 } else { 3548 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3549 } 3550 break; 3551 default: 3552 sm_conn->sm_bonding_requested = 1; 3553 break; 3554 } 3555 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3556 sm_conn->sm_bonding_requested = 1; 3557 } 3558 } 3559 sm_run(); 3560 } 3561 3562 // called by client app on authorization request 3563 void sm_authorization_decline(hci_con_handle_t con_handle){ 3564 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3565 if (!sm_conn) return; // wrong connection 3566 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3567 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3568 } 3569 3570 void sm_authorization_grant(hci_con_handle_t con_handle){ 3571 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3572 if (!sm_conn) return; // wrong connection 3573 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3574 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3575 } 3576 3577 // GAP Bonding API 3578 3579 void sm_bonding_decline(hci_con_handle_t con_handle){ 3580 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3581 if (!sm_conn) return; // wrong connection 3582 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3583 3584 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3585 switch (setup->sm_stk_generation_method){ 3586 case PK_RESP_INPUT: 3587 case PK_INIT_INPUT: 3588 case OK_BOTH_INPUT: 3589 sm_pairing_error(sm_conn, SM_GENERAL_SEND_PAIRING_FAILED); 3590 break; 3591 case NK_BOTH_INPUT: 3592 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 3593 break; 3594 case JUST_WORKS: 3595 case OOB: 3596 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 3597 break; 3598 } 3599 } 3600 sm_run(); 3601 } 3602 3603 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3604 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3605 if (!sm_conn) return; // wrong connection 3606 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3607 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3608 if (setup->sm_use_secure_connections){ 3609 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3610 } else { 3611 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3612 } 3613 } 3614 3615 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3616 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3617 sm_sc_prepare_dhkey_check(sm_conn); 3618 } 3619 #endif 3620 3621 sm_run(); 3622 } 3623 3624 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3625 // for now, it's the same 3626 sm_just_works_confirm(con_handle); 3627 } 3628 3629 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3630 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3631 if (!sm_conn) return; // wrong connection 3632 sm_reset_tk(); 3633 big_endian_store_32(setup->sm_tk, 12, passkey); 3634 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3635 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3636 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3637 } 3638 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3639 memcpy(setup->sm_ra, setup->sm_tk, 16); 3640 memcpy(setup->sm_rb, setup->sm_tk, 16); 3641 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3642 sm_sc_start_calculating_local_confirm(sm_conn); 3643 } 3644 #endif 3645 sm_run(); 3646 } 3647 3648 /** 3649 * @brief Identify device in LE Device DB 3650 * @param handle 3651 * @returns index from le_device_db or -1 if not found/identified 3652 */ 3653 int sm_le_device_index(hci_con_handle_t con_handle ){ 3654 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3655 if (!sm_conn) return -1; 3656 return sm_conn->sm_le_db_index; 3657 } 3658 3659 // GAP LE API 3660 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 3661 gap_random_address_update_stop(); 3662 gap_random_adress_type = random_address_type; 3663 if (random_address_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3664 gap_random_address_update_start(); 3665 gap_random_address_trigger(); 3666 } 3667 3668 gap_random_address_type_t gap_random_address_get_mode(void){ 3669 return gap_random_adress_type; 3670 } 3671 3672 void gap_random_address_set_update_period(int period_ms){ 3673 gap_random_adress_update_period = period_ms; 3674 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3675 gap_random_address_update_stop(); 3676 gap_random_address_update_start(); 3677 } 3678 3679 void gap_random_address_set(bd_addr_t addr){ 3680 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_OFF); 3681 memcpy(sm_random_address, addr, 6); 3682 rau_state = RAU_SET_ADDRESS; 3683 sm_run(); 3684 } 3685 3686 /* 3687 * @brief Set Advertisement Paramters 3688 * @param adv_int_min 3689 * @param adv_int_max 3690 * @param adv_type 3691 * @param direct_address_type 3692 * @param direct_address 3693 * @param channel_map 3694 * @param filter_policy 3695 * 3696 * @note own_address_type is used from gap_random_address_set_mode 3697 */ 3698 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 3699 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 3700 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, gap_random_adress_type, 3701 direct_address_typ, direct_address, channel_map, filter_policy); 3702 } 3703 3704