1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 #include <stdio.h> 39 #include <string.h> 40 #include <inttypes.h> 41 42 #include "ble/le_device_db.h" 43 #include "ble/core.h" 44 #include "ble/sm.h" 45 #include "btstack_debug.h" 46 #include "btstack_event.h" 47 #include "btstack_linked_list.h" 48 #include "btstack_memory.h" 49 #include "gap.h" 50 #include "hci.h" 51 #include "l2cap.h" 52 53 #ifdef ENABLE_LE_SECURE_CONNECTIONS 54 #ifdef HAVE_HCI_CONTROLLER_DHKEY_SUPPORT 55 #error "Support for DHKEY Support in HCI Controller not implemented yet. Please use software implementation" 56 #else 57 #define USE_MBEDTLS_FOR_ECDH 58 #endif 59 #endif 60 61 62 // Software ECDH implementation provided by mbedtls 63 #ifdef USE_MBEDTLS_FOR_ECDH 64 #include "mbedtls/config.h" 65 #include "mbedtls/platform.h" 66 #include "mbedtls/ecp.h" 67 #include "sm_mbedtls_allocator.h" 68 #endif 69 70 // 71 // SM internal types and globals 72 // 73 74 typedef enum { 75 DKG_W4_WORKING, 76 DKG_CALC_IRK, 77 DKG_W4_IRK, 78 DKG_CALC_DHK, 79 DKG_W4_DHK, 80 DKG_READY 81 } derived_key_generation_t; 82 83 typedef enum { 84 RAU_W4_WORKING, 85 RAU_IDLE, 86 RAU_GET_RANDOM, 87 RAU_W4_RANDOM, 88 RAU_GET_ENC, 89 RAU_W4_ENC, 90 RAU_SET_ADDRESS, 91 } random_address_update_t; 92 93 typedef enum { 94 CMAC_IDLE, 95 CMAC_CALC_SUBKEYS, 96 CMAC_W4_SUBKEYS, 97 CMAC_CALC_MI, 98 CMAC_W4_MI, 99 CMAC_CALC_MLAST, 100 CMAC_W4_MLAST 101 } cmac_state_t; 102 103 typedef enum { 104 JUST_WORKS, 105 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 106 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 107 OK_BOTH_INPUT, // Only input on both, both input PK 108 NK_BOTH_INPUT, // Only numerical compparison (yes/no) on on both sides 109 OOB // OOB available on both sides 110 } stk_generation_method_t; 111 112 typedef enum { 113 SM_USER_RESPONSE_IDLE, 114 SM_USER_RESPONSE_PENDING, 115 SM_USER_RESPONSE_CONFIRM, 116 SM_USER_RESPONSE_PASSKEY, 117 SM_USER_RESPONSE_DECLINE 118 } sm_user_response_t; 119 120 typedef enum { 121 SM_AES128_IDLE, 122 SM_AES128_ACTIVE 123 } sm_aes128_state_t; 124 125 typedef enum { 126 ADDRESS_RESOLUTION_IDLE, 127 ADDRESS_RESOLUTION_GENERAL, 128 ADDRESS_RESOLUTION_FOR_CONNECTION, 129 } address_resolution_mode_t; 130 131 typedef enum { 132 ADDRESS_RESOLUTION_SUCEEDED, 133 ADDRESS_RESOLUTION_FAILED, 134 } address_resolution_event_t; 135 136 typedef enum { 137 EC_KEY_GENERATION_IDLE, 138 EC_KEY_GENERATION_ACTIVE, 139 EC_KEY_GENERATION_DONE, 140 } ec_key_generation_state_t; 141 142 typedef enum { 143 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 0 144 } sm_state_var_t; 145 146 // 147 // GLOBAL DATA 148 // 149 150 static uint8_t test_use_fixed_local_csrk; 151 152 // configuration 153 static uint8_t sm_accepted_stk_generation_methods; 154 static uint8_t sm_max_encryption_key_size; 155 static uint8_t sm_min_encryption_key_size; 156 static uint8_t sm_auth_req = 0; 157 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 158 static uint8_t sm_slave_request_security; 159 #ifdef ENABLE_LE_SECURE_CONNECTIONS 160 static uint8_t sm_have_ec_keypair; 161 #endif 162 163 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 164 static sm_key_t sm_persistent_er; 165 static sm_key_t sm_persistent_ir; 166 167 // derived from sm_persistent_ir 168 static sm_key_t sm_persistent_dhk; 169 static sm_key_t sm_persistent_irk; 170 static uint8_t sm_persistent_irk_ready = 0; // used for testing 171 static derived_key_generation_t dkg_state; 172 173 // derived from sm_persistent_er 174 // .. 175 176 // random address update 177 static random_address_update_t rau_state; 178 static bd_addr_t sm_random_address; 179 180 // CMAC Calculation: General 181 static cmac_state_t sm_cmac_state; 182 static uint16_t sm_cmac_message_len; 183 static sm_key_t sm_cmac_k; 184 static sm_key_t sm_cmac_x; 185 static sm_key_t sm_cmac_m_last; 186 static uint8_t sm_cmac_block_current; 187 static uint8_t sm_cmac_block_count; 188 static uint8_t (*sm_cmac_get_byte)(uint16_t offset); 189 static void (*sm_cmac_done_handler)(uint8_t * hash); 190 191 // CMAC for ATT Signed Writes 192 static uint8_t sm_cmac_header[3]; 193 static const uint8_t * sm_cmac_message; 194 static uint8_t sm_cmac_sign_counter[4]; 195 196 // CMAC for Secure Connection functions 197 #ifdef ENABLE_LE_SECURE_CONNECTIONS 198 static sm_connection_t * sm_cmac_connection; 199 static uint8_t sm_cmac_sc_buffer[80]; 200 #endif 201 202 // resolvable private address lookup / CSRK calculation 203 static int sm_address_resolution_test; 204 static int sm_address_resolution_ah_calculation_active; 205 static uint8_t sm_address_resolution_addr_type; 206 static bd_addr_t sm_address_resolution_address; 207 static void * sm_address_resolution_context; 208 static address_resolution_mode_t sm_address_resolution_mode; 209 static btstack_linked_list_t sm_address_resolution_general_queue; 210 211 // aes128 crypto engine. store current sm_connection_t in sm_aes128_context 212 static sm_aes128_state_t sm_aes128_state; 213 static void * sm_aes128_context; 214 215 // random engine. store context (ususally sm_connection_t) 216 static void * sm_random_context; 217 218 // to receive hci events 219 static btstack_packet_callback_registration_t hci_event_callback_registration; 220 221 /* to dispatch sm event */ 222 static btstack_linked_list_t sm_event_handlers; 223 224 225 // Software ECDH implementation provided by mbedtls 226 #ifdef USE_MBEDTLS_FOR_ECDH 227 // group is always valid 228 static mbedtls_ecp_group mbedtls_ec_group; 229 static ec_key_generation_state_t ec_key_generation_state; 230 static uint8_t ec_qx[32]; 231 static uint8_t ec_qy[32]; 232 static uint8_t ec_d[32]; 233 #ifndef HAVE_MALLOC 234 // 4304 bytes with 73 allocations 235 #define MBEDTLS_ALLOC_BUFFER_SIZE (1300+23*sizeof(void *)) 236 static uint8_t mbedtls_memory_buffer[MBEDTLS_ALLOC_BUFFER_SIZE]; 237 #endif 238 #endif 239 240 // 241 // Volume 3, Part H, Chapter 24 242 // "Security shall be initiated by the Security Manager in the device in the master role. 243 // The device in the slave role shall be the responding device." 244 // -> master := initiator, slave := responder 245 // 246 247 // data needed for security setup 248 typedef struct sm_setup_context { 249 250 btstack_timer_source_t sm_timeout; 251 252 // used in all phases 253 uint8_t sm_pairing_failed_reason; 254 255 // user response, (Phase 1 and/or 2) 256 uint8_t sm_user_response; 257 uint8_t sm_keypress_notification; 258 259 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 260 int sm_key_distribution_send_set; 261 int sm_key_distribution_received_set; 262 263 // Phase 2 (Pairing over SMP) 264 stk_generation_method_t sm_stk_generation_method; 265 sm_key_t sm_tk; 266 uint8_t sm_use_secure_connections; 267 268 sm_key_t sm_c1_t3_value; // c1 calculation 269 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 270 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 271 sm_key_t sm_local_random; 272 sm_key_t sm_local_confirm; 273 sm_key_t sm_peer_random; 274 sm_key_t sm_peer_confirm; 275 uint8_t sm_m_addr_type; // address and type can be removed 276 uint8_t sm_s_addr_type; // '' 277 bd_addr_t sm_m_address; // '' 278 bd_addr_t sm_s_address; // '' 279 sm_key_t sm_ltk; 280 281 uint8_t sm_state_vars; 282 #ifdef ENABLE_LE_SECURE_CONNECTIONS 283 uint8_t sm_peer_qx[32]; // also stores random for EC key generation during init 284 uint8_t sm_peer_qy[32]; // '' 285 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 286 sm_key_t sm_local_nonce; // might be combined with sm_local_random 287 sm_key_t sm_peer_dhkey_check; 288 sm_key_t sm_local_dhkey_check; 289 sm_key_t sm_ra; 290 sm_key_t sm_rb; 291 sm_key_t sm_t; // used for f5 292 sm_key_t sm_mackey; 293 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 294 #endif 295 296 // Phase 3 297 298 // key distribution, we generate 299 uint16_t sm_local_y; 300 uint16_t sm_local_div; 301 uint16_t sm_local_ediv; 302 uint8_t sm_local_rand[8]; 303 sm_key_t sm_local_ltk; 304 sm_key_t sm_local_csrk; 305 sm_key_t sm_local_irk; 306 // sm_local_address/addr_type not needed 307 308 // key distribution, received from peer 309 uint16_t sm_peer_y; 310 uint16_t sm_peer_div; 311 uint16_t sm_peer_ediv; 312 uint8_t sm_peer_rand[8]; 313 sm_key_t sm_peer_ltk; 314 sm_key_t sm_peer_irk; 315 sm_key_t sm_peer_csrk; 316 uint8_t sm_peer_addr_type; 317 bd_addr_t sm_peer_address; 318 319 } sm_setup_context_t; 320 321 // 322 static sm_setup_context_t the_setup; 323 static sm_setup_context_t * setup = &the_setup; 324 325 // active connection - the one for which the_setup is used for 326 static uint16_t sm_active_connection = 0; 327 328 // @returns 1 if oob data is available 329 // stores oob data in provided 16 byte buffer if not null 330 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 331 332 // used to notify applicationss that user interaction is neccessary, see sm_notify_t below 333 static btstack_packet_handler_t sm_client_packet_handler = NULL; 334 335 // horizontal: initiator capabilities 336 // vertial: responder capabilities 337 static const stk_generation_method_t stk_generation_method [5] [5] = { 338 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 339 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 340 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 341 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 342 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 343 }; 344 345 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 346 #ifdef ENABLE_LE_SECURE_CONNECTIONS 347 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 348 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 349 { JUST_WORKS, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 350 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 351 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 352 { PK_RESP_INPUT, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 353 }; 354 #endif 355 356 static void sm_run(void); 357 static void sm_done_for_handle(hci_con_handle_t con_handle); 358 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 359 static inline int sm_calc_actual_encryption_key_size(int other); 360 static int sm_validate_stk_generation_method(void); 361 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data); 362 363 static void log_info_hex16(const char * name, uint16_t value){ 364 log_info("%-6s 0x%04x", name, value); 365 } 366 367 // @returns 1 if all bytes are 0 368 static int sm_is_null(uint8_t * data, int size){ 369 int i; 370 for (i=0; i < size ; i++){ 371 if (data[i]) return 0; 372 } 373 return 1; 374 } 375 376 static int sm_is_null_random(uint8_t random[8]){ 377 return sm_is_null(random, 8); 378 } 379 380 static int sm_is_null_key(uint8_t * key){ 381 return sm_is_null(key, 16); 382 } 383 384 // Key utils 385 static void sm_reset_tk(void){ 386 int i; 387 for (i=0;i<16;i++){ 388 setup->sm_tk[i] = 0; 389 } 390 } 391 392 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 393 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 394 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 395 int i; 396 for (i = max_encryption_size ; i < 16 ; i++){ 397 key[15-i] = 0; 398 } 399 } 400 401 // SMP Timeout implementation 402 403 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 404 // the Security Manager Timer shall be reset and started. 405 // 406 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 407 // 408 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 409 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 410 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 411 // established. 412 413 static void sm_timeout_handler(btstack_timer_source_t * timer){ 414 log_info("SM timeout"); 415 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 416 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 417 sm_done_for_handle(sm_conn->sm_handle); 418 419 // trigger handling of next ready connection 420 sm_run(); 421 } 422 static void sm_timeout_start(sm_connection_t * sm_conn){ 423 btstack_run_loop_remove_timer(&setup->sm_timeout); 424 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 425 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 426 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 427 btstack_run_loop_add_timer(&setup->sm_timeout); 428 } 429 static void sm_timeout_stop(void){ 430 btstack_run_loop_remove_timer(&setup->sm_timeout); 431 } 432 static void sm_timeout_reset(sm_connection_t * sm_conn){ 433 sm_timeout_stop(); 434 sm_timeout_start(sm_conn); 435 } 436 437 // end of sm timeout 438 439 // GAP Random Address updates 440 static gap_random_address_type_t gap_random_adress_type; 441 static btstack_timer_source_t gap_random_address_update_timer; 442 static uint32_t gap_random_adress_update_period; 443 444 static void gap_random_address_trigger(void){ 445 if (rau_state != RAU_IDLE) return; 446 log_info("gap_random_address_trigger"); 447 rau_state = RAU_GET_RANDOM; 448 sm_run(); 449 } 450 451 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 452 log_info("GAP Random Address Update due"); 453 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 454 btstack_run_loop_add_timer(&gap_random_address_update_timer); 455 gap_random_address_trigger(); 456 } 457 458 static void gap_random_address_update_start(void){ 459 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 460 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 461 btstack_run_loop_add_timer(&gap_random_address_update_timer); 462 } 463 464 static void gap_random_address_update_stop(void){ 465 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 466 } 467 468 469 static void sm_random_start(void * context){ 470 sm_random_context = context; 471 hci_send_cmd(&hci_le_rand); 472 } 473 474 // pre: sm_aes128_state != SM_AES128_ACTIVE, hci_can_send_command == 1 475 // context is made availabe to aes128 result handler by this 476 static void sm_aes128_start(sm_key_t key, sm_key_t plaintext, void * context){ 477 sm_aes128_state = SM_AES128_ACTIVE; 478 sm_key_t key_flipped, plaintext_flipped; 479 reverse_128(key, key_flipped); 480 reverse_128(plaintext, plaintext_flipped); 481 sm_aes128_context = context; 482 hci_send_cmd(&hci_le_encrypt, key_flipped, plaintext_flipped); 483 } 484 485 // ah(k,r) helper 486 // r = padding || r 487 // r - 24 bit value 488 static void sm_ah_r_prime(uint8_t r[3], sm_key_t r_prime){ 489 // r'= padding || r 490 memset(r_prime, 0, 16); 491 memcpy(&r_prime[13], r, 3); 492 } 493 494 // d1 helper 495 // d' = padding || r || d 496 // d,r - 16 bit values 497 static void sm_d1_d_prime(uint16_t d, uint16_t r, sm_key_t d1_prime){ 498 // d'= padding || r || d 499 memset(d1_prime, 0, 16); 500 big_endian_store_16(d1_prime, 12, r); 501 big_endian_store_16(d1_prime, 14, d); 502 } 503 504 // dm helper 505 // r’ = padding || r 506 // r - 64 bit value 507 static void sm_dm_r_prime(uint8_t r[8], sm_key_t r_prime){ 508 memset(r_prime, 0, 16); 509 memcpy(&r_prime[8], r, 8); 510 } 511 512 // calculate arguments for first AES128 operation in C1 function 513 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){ 514 515 // p1 = pres || preq || rat’ || iat’ 516 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 517 // cant octet of pres becomes the most significant octet of p1. 518 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 519 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 520 // p1 is 0x05000800000302070710000001010001." 521 522 sm_key_t p1; 523 reverse_56(pres, &p1[0]); 524 reverse_56(preq, &p1[7]); 525 p1[14] = rat; 526 p1[15] = iat; 527 log_info_key("p1", p1); 528 log_info_key("r", r); 529 530 // t1 = r xor p1 531 int i; 532 for (i=0;i<16;i++){ 533 t1[i] = r[i] ^ p1[i]; 534 } 535 log_info_key("t1", t1); 536 } 537 538 // calculate arguments for second AES128 operation in C1 function 539 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, sm_key_t t3){ 540 // p2 = padding || ia || ra 541 // "The least significant octet of ra becomes the least significant octet of p2 and 542 // the most significant octet of padding becomes the most significant octet of p2. 543 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 544 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 545 546 sm_key_t p2; 547 memset(p2, 0, 16); 548 memcpy(&p2[4], ia, 6); 549 memcpy(&p2[10], ra, 6); 550 log_info_key("p2", p2); 551 552 // c1 = e(k, t2_xor_p2) 553 int i; 554 for (i=0;i<16;i++){ 555 t3[i] = t2[i] ^ p2[i]; 556 } 557 log_info_key("t3", t3); 558 } 559 560 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, sm_key_t r_prime){ 561 log_info_key("r1", r1); 562 log_info_key("r2", r2); 563 memcpy(&r_prime[8], &r2[8], 8); 564 memcpy(&r_prime[0], &r1[8], 8); 565 } 566 567 #ifdef ENABLE_LE_SECURE_CONNECTIONS 568 // Software implementations of crypto toolbox for LE Secure Connection 569 // TODO: replace with code to use AES Engine of HCI Controller 570 typedef uint8_t sm_key24_t[3]; 571 typedef uint8_t sm_key56_t[7]; 572 typedef uint8_t sm_key256_t[32]; 573 574 #if 0 575 static void aes128_calc_cyphertext(const uint8_t key[16], const uint8_t plaintext[16], uint8_t cyphertext[16]){ 576 uint32_t rk[RKLENGTH(KEYBITS)]; 577 int nrounds = rijndaelSetupEncrypt(rk, &key[0], KEYBITS); 578 rijndaelEncrypt(rk, nrounds, plaintext, cyphertext); 579 } 580 581 static void calc_subkeys(sm_key_t k0, sm_key_t k1, sm_key_t k2){ 582 memcpy(k1, k0, 16); 583 sm_shift_left_by_one_bit_inplace(16, k1); 584 if (k0[0] & 0x80){ 585 k1[15] ^= 0x87; 586 } 587 memcpy(k2, k1, 16); 588 sm_shift_left_by_one_bit_inplace(16, k2); 589 if (k1[0] & 0x80){ 590 k2[15] ^= 0x87; 591 } 592 } 593 594 static void aes_cmac(sm_key_t aes_cmac, const sm_key_t key, const uint8_t * data, int cmac_message_len){ 595 sm_key_t k0, k1, k2, zero; 596 memset(zero, 0, 16); 597 598 aes128_calc_cyphertext(key, zero, k0); 599 calc_subkeys(k0, k1, k2); 600 601 int cmac_block_count = (cmac_message_len + 15) / 16; 602 603 // step 3: .. 604 if (cmac_block_count==0){ 605 cmac_block_count = 1; 606 } 607 608 // step 4: set m_last 609 sm_key_t cmac_m_last; 610 int sm_cmac_last_block_complete = cmac_message_len != 0 && (cmac_message_len & 0x0f) == 0; 611 int i; 612 if (sm_cmac_last_block_complete){ 613 for (i=0;i<16;i++){ 614 cmac_m_last[i] = data[cmac_message_len - 16 + i] ^ k1[i]; 615 } 616 } else { 617 int valid_octets_in_last_block = cmac_message_len & 0x0f; 618 for (i=0;i<16;i++){ 619 if (i < valid_octets_in_last_block){ 620 cmac_m_last[i] = data[(cmac_message_len & 0xfff0) + i] ^ k2[i]; 621 continue; 622 } 623 if (i == valid_octets_in_last_block){ 624 cmac_m_last[i] = 0x80 ^ k2[i]; 625 continue; 626 } 627 cmac_m_last[i] = k2[i]; 628 } 629 } 630 631 // printf("sm_cmac_start: len %u, block count %u\n", cmac_message_len, cmac_block_count); 632 // LOG_KEY(cmac_m_last); 633 634 // Step 5 635 sm_key_t cmac_x; 636 memset(cmac_x, 0, 16); 637 638 // Step 6 639 sm_key_t sm_cmac_y; 640 for (int block = 0 ; block < cmac_block_count-1 ; block++){ 641 for (i=0;i<16;i++){ 642 sm_cmac_y[i] = cmac_x[i] ^ data[block * 16 + i]; 643 } 644 aes128_calc_cyphertext(key, sm_cmac_y, cmac_x); 645 } 646 for (i=0;i<16;i++){ 647 sm_cmac_y[i] = cmac_x[i] ^ cmac_m_last[i]; 648 } 649 650 // Step 7 651 aes128_calc_cyphertext(key, sm_cmac_y, aes_cmac); 652 } 653 #endif 654 655 #if 0 656 // 657 // Link Key Conversion Function h6 658 // 659 // h6(W, keyID) = AES-CMACW(keyID) 660 // - W is 128 bits 661 // - keyID is 32 bits 662 static void h6(sm_key_t res, const sm_key_t w, const uint32_t key_id){ 663 uint8_t key_id_buffer[4]; 664 big_endian_store_32(key_id_buffer, 0, key_id); 665 aes_cmac(res, w, key_id_buffer, 4); 666 } 667 #endif 668 #endif 669 670 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){ 671 event[0] = type; 672 event[1] = event_size - 2; 673 little_endian_store_16(event, 2, con_handle); 674 event[4] = addr_type; 675 reverse_bd_addr(address, &event[5]); 676 } 677 678 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 679 if (sm_client_packet_handler) { 680 sm_client_packet_handler(HCI_EVENT_PACKET, 0, packet, size); 681 } 682 // dispatch to all event handlers 683 btstack_linked_list_iterator_t it; 684 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 685 while (btstack_linked_list_iterator_has_next(&it)){ 686 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 687 entry->callback(packet_type, 0, packet, size); 688 } 689 } 690 691 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 692 uint8_t event[11]; 693 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 694 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 695 } 696 697 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){ 698 uint8_t event[15]; 699 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 700 little_endian_store_32(event, 11, passkey); 701 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 702 } 703 704 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){ 705 uint8_t event[13]; 706 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 707 little_endian_store_16(event, 11, index); 708 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 709 } 710 711 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){ 712 713 uint8_t event[18]; 714 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 715 event[11] = result; 716 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 717 } 718 719 // decide on stk generation based on 720 // - pairing request 721 // - io capabilities 722 // - OOB data availability 723 static void sm_setup_tk(void){ 724 725 // default: just works 726 setup->sm_stk_generation_method = JUST_WORKS; 727 728 #ifdef ENABLE_LE_SECURE_CONNECTIONS 729 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 730 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 731 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 732 memset(setup->sm_ra, 0, 16); 733 memset(setup->sm_rb, 0, 16); 734 #else 735 setup->sm_use_secure_connections = 0; 736 #endif 737 738 // If both devices have not set the MITM option in the Authentication Requirements 739 // Flags, then the IO capabilities shall be ignored and the Just Works association 740 // model shall be used. 741 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 742 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 743 log_info("SM: MITM not required by both -> JUST WORKS"); 744 return; 745 } 746 747 // TODO: with LE SC, OOB is used to transfer data OOB during pairing, single device with OOB is sufficient 748 749 // If both devices have out of band authentication data, then the Authentication 750 // Requirements Flags shall be ignored when selecting the pairing method and the 751 // Out of Band pairing method shall be used. 752 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) 753 && sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)){ 754 log_info("SM: have OOB data"); 755 log_info_key("OOB", setup->sm_tk); 756 setup->sm_stk_generation_method = OOB; 757 return; 758 } 759 760 // Reset TK as it has been setup in sm_init_setup 761 sm_reset_tk(); 762 763 // Also use just works if unknown io capabilites 764 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)){ 765 return; 766 } 767 768 // Otherwise the IO capabilities of the devices shall be used to determine the 769 // pairing method as defined in Table 2.4. 770 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 771 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 772 773 #ifdef ENABLE_LE_SECURE_CONNECTIONS 774 // table not define by default 775 if (setup->sm_use_secure_connections){ 776 generation_method = stk_generation_method_with_secure_connection; 777 } 778 #endif 779 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)]; 780 781 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 782 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); 783 } 784 785 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 786 int flags = 0; 787 if (key_set & SM_KEYDIST_ENC_KEY){ 788 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 789 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 790 } 791 if (key_set & SM_KEYDIST_ID_KEY){ 792 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 793 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 794 } 795 if (key_set & SM_KEYDIST_SIGN){ 796 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 797 } 798 return flags; 799 } 800 801 static void sm_setup_key_distribution(uint8_t key_set){ 802 setup->sm_key_distribution_received_set = 0; 803 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 804 } 805 806 // CSRK Key Lookup 807 808 809 static int sm_address_resolution_idle(void){ 810 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 811 } 812 813 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){ 814 memcpy(sm_address_resolution_address, addr, 6); 815 sm_address_resolution_addr_type = addr_type; 816 sm_address_resolution_test = 0; 817 sm_address_resolution_mode = mode; 818 sm_address_resolution_context = context; 819 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 820 } 821 822 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 823 // check if already in list 824 btstack_linked_list_iterator_t it; 825 sm_lookup_entry_t * entry; 826 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 827 while(btstack_linked_list_iterator_has_next(&it)){ 828 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 829 if (entry->address_type != address_type) continue; 830 if (memcmp(entry->address, address, 6)) continue; 831 // already in list 832 return BTSTACK_BUSY; 833 } 834 entry = btstack_memory_sm_lookup_entry_get(); 835 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 836 entry->address_type = (bd_addr_type_t) address_type; 837 memcpy(entry->address, address, 6); 838 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 839 sm_run(); 840 return 0; 841 } 842 843 // CMAC Implementation using AES128 engine 844 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 845 int i; 846 int carry = 0; 847 for (i=len-1; i >= 0 ; i--){ 848 int new_carry = data[i] >> 7; 849 data[i] = data[i] << 1 | carry; 850 carry = new_carry; 851 } 852 } 853 854 // 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 855 static inline void sm_next_responding_state(sm_connection_t * sm_conn){ 856 sm_conn->sm_engine_state = (security_manager_state_t) (((int)sm_conn->sm_engine_state) + 1); 857 } 858 static inline void dkg_next_state(void){ 859 dkg_state = (derived_key_generation_t) (((int)dkg_state) + 1); 860 } 861 static inline void rau_next_state(void){ 862 rau_state = (random_address_update_t) (((int)rau_state) + 1); 863 } 864 865 // CMAC calculation using AES Engine 866 867 static inline void sm_cmac_next_state(void){ 868 sm_cmac_state = (cmac_state_t) (((int)sm_cmac_state) + 1); 869 } 870 871 static int sm_cmac_last_block_complete(void){ 872 if (sm_cmac_message_len == 0) return 0; 873 return (sm_cmac_message_len & 0x0f) == 0; 874 } 875 876 static inline uint8_t sm_cmac_message_get_byte(uint16_t offset){ 877 if (offset >= sm_cmac_message_len) { 878 log_error("sm_cmac_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_message_len); 879 return 0; 880 } 881 882 offset = sm_cmac_message_len - 1 - offset; 883 884 // sm_cmac_header[3] | message[] | sm_cmac_sign_counter[4] 885 if (offset < 3){ 886 return sm_cmac_header[offset]; 887 } 888 int actual_message_len_incl_header = sm_cmac_message_len - 4; 889 if (offset < actual_message_len_incl_header){ 890 return sm_cmac_message[offset - 3]; 891 } 892 return sm_cmac_sign_counter[offset - actual_message_len_incl_header]; 893 } 894 895 // generic cmac calculation 896 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])){ 897 // Generalized CMAC 898 memcpy(sm_cmac_k, key, 16); 899 memset(sm_cmac_x, 0, 16); 900 sm_cmac_block_current = 0; 901 sm_cmac_message_len = message_len; 902 sm_cmac_done_handler = done_callback; 903 sm_cmac_get_byte = get_byte_callback; 904 905 // step 2: n := ceil(len/const_Bsize); 906 sm_cmac_block_count = (sm_cmac_message_len + 15) / 16; 907 908 // step 3: .. 909 if (sm_cmac_block_count==0){ 910 sm_cmac_block_count = 1; 911 } 912 log_info("sm_cmac_general_start: len %u, block count %u", sm_cmac_message_len, sm_cmac_block_count); 913 914 // first, we need to compute l for k1, k2, and m_last 915 sm_cmac_state = CMAC_CALC_SUBKEYS; 916 917 // let's go 918 sm_run(); 919 } 920 921 // cmac for ATT Message signing 922 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)){ 923 // ATT Message Signing 924 sm_cmac_header[0] = opcode; 925 little_endian_store_16(sm_cmac_header, 1, con_handle); 926 little_endian_store_32(sm_cmac_sign_counter, 0, sign_counter); 927 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 928 sm_cmac_message = message; 929 sm_cmac_general_start(k, total_message_len, &sm_cmac_message_get_byte, done_handler); 930 } 931 932 int sm_cmac_ready(void){ 933 return sm_cmac_state == CMAC_IDLE; 934 } 935 936 static void sm_cmac_handle_aes_engine_ready(void){ 937 switch (sm_cmac_state){ 938 case CMAC_CALC_SUBKEYS: { 939 sm_key_t const_zero; 940 memset(const_zero, 0, 16); 941 sm_cmac_next_state(); 942 sm_aes128_start(sm_cmac_k, const_zero, NULL); 943 break; 944 } 945 case CMAC_CALC_MI: { 946 int j; 947 sm_key_t y; 948 for (j=0;j<16;j++){ 949 y[j] = sm_cmac_x[j] ^ sm_cmac_get_byte(sm_cmac_block_current*16 + j); 950 } 951 sm_cmac_block_current++; 952 sm_cmac_next_state(); 953 sm_aes128_start(sm_cmac_k, y, NULL); 954 break; 955 } 956 case CMAC_CALC_MLAST: { 957 int i; 958 sm_key_t y; 959 for (i=0;i<16;i++){ 960 y[i] = sm_cmac_x[i] ^ sm_cmac_m_last[i]; 961 } 962 log_info_key("Y", y); 963 sm_cmac_block_current++; 964 sm_cmac_next_state(); 965 sm_aes128_start(sm_cmac_k, y, NULL); 966 break; 967 } 968 default: 969 log_info("sm_cmac_handle_aes_engine_ready called in state %u", sm_cmac_state); 970 break; 971 } 972 } 973 974 static void sm_cmac_handle_encryption_result(sm_key_t data){ 975 switch (sm_cmac_state){ 976 case CMAC_W4_SUBKEYS: { 977 sm_key_t k1; 978 memcpy(k1, data, 16); 979 sm_shift_left_by_one_bit_inplace(16, k1); 980 if (data[0] & 0x80){ 981 k1[15] ^= 0x87; 982 } 983 sm_key_t k2; 984 memcpy(k2, k1, 16); 985 sm_shift_left_by_one_bit_inplace(16, k2); 986 if (k1[0] & 0x80){ 987 k2[15] ^= 0x87; 988 } 989 990 log_info_key("k", sm_cmac_k); 991 log_info_key("k1", k1); 992 log_info_key("k2", k2); 993 994 // step 4: set m_last 995 int i; 996 if (sm_cmac_last_block_complete()){ 997 for (i=0;i<16;i++){ 998 sm_cmac_m_last[i] = sm_cmac_get_byte(sm_cmac_message_len - 16 + i) ^ k1[i]; 999 } 1000 } else { 1001 int valid_octets_in_last_block = sm_cmac_message_len & 0x0f; 1002 for (i=0;i<16;i++){ 1003 if (i < valid_octets_in_last_block){ 1004 sm_cmac_m_last[i] = sm_cmac_get_byte((sm_cmac_message_len & 0xfff0) + i) ^ k2[i]; 1005 continue; 1006 } 1007 if (i == valid_octets_in_last_block){ 1008 sm_cmac_m_last[i] = 0x80 ^ k2[i]; 1009 continue; 1010 } 1011 sm_cmac_m_last[i] = k2[i]; 1012 } 1013 } 1014 1015 // next 1016 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1017 break; 1018 } 1019 case CMAC_W4_MI: 1020 memcpy(sm_cmac_x, data, 16); 1021 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1022 break; 1023 case CMAC_W4_MLAST: 1024 // done 1025 log_info("Setting CMAC Engine to IDLE"); 1026 sm_cmac_state = CMAC_IDLE; 1027 log_info_key("CMAC", data); 1028 sm_cmac_done_handler(data); 1029 break; 1030 default: 1031 log_info("sm_cmac_handle_encryption_result called in state %u", sm_cmac_state); 1032 break; 1033 } 1034 } 1035 1036 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 1037 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 1038 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 1039 switch (setup->sm_stk_generation_method){ 1040 case PK_RESP_INPUT: 1041 if (sm_conn->sm_role){ 1042 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1043 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1044 } else { 1045 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)); 1046 } 1047 break; 1048 case PK_INIT_INPUT: 1049 if (sm_conn->sm_role){ 1050 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)); 1051 } else { 1052 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1053 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1054 } 1055 break; 1056 case OK_BOTH_INPUT: 1057 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1058 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1059 break; 1060 case NK_BOTH_INPUT: 1061 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1062 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)); 1063 break; 1064 case JUST_WORKS: 1065 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1066 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1067 break; 1068 case OOB: 1069 // client already provided OOB data, let's skip notification. 1070 break; 1071 } 1072 } 1073 1074 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 1075 int recv_flags; 1076 if (sm_conn->sm_role){ 1077 // slave / responder 1078 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 1079 } else { 1080 // master / initiator 1081 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 1082 } 1083 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1084 return recv_flags == setup->sm_key_distribution_received_set; 1085 } 1086 1087 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1088 if (sm_active_connection == con_handle){ 1089 sm_timeout_stop(); 1090 sm_active_connection = 0; 1091 log_info("sm: connection 0x%x released setup context", con_handle); 1092 } 1093 } 1094 1095 static int sm_key_distribution_flags_for_auth_req(void){ 1096 int flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_SIGN; 1097 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1098 // encryption information only if bonding requested 1099 flags |= SM_KEYDIST_ENC_KEY; 1100 } 1101 return flags; 1102 } 1103 1104 static void sm_init_setup(sm_connection_t * sm_conn){ 1105 1106 // fill in sm setup 1107 setup->sm_state_vars = 0; 1108 setup->sm_keypress_notification = 0xff; 1109 sm_reset_tk(); 1110 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1111 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1112 1113 // query client for OOB data 1114 int have_oob_data = 0; 1115 if (sm_get_oob_data) { 1116 have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1117 } 1118 1119 sm_pairing_packet_t * local_packet; 1120 if (sm_conn->sm_role){ 1121 // slave 1122 local_packet = &setup->sm_s_pres; 1123 gap_advertisements_get_address(&setup->sm_s_addr_type, setup->sm_s_address); 1124 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1125 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1126 } else { 1127 // master 1128 local_packet = &setup->sm_m_preq; 1129 gap_advertisements_get_address(&setup->sm_m_addr_type, setup->sm_m_address); 1130 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1131 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1132 1133 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1134 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1135 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1136 } 1137 1138 uint8_t auth_req = sm_auth_req; 1139 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1140 sm_pairing_packet_set_oob_data_flag(*local_packet, have_oob_data); 1141 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1142 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1143 } 1144 1145 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1146 1147 sm_pairing_packet_t * remote_packet; 1148 int remote_key_request; 1149 if (sm_conn->sm_role){ 1150 // slave / responder 1151 remote_packet = &setup->sm_m_preq; 1152 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1153 } else { 1154 // master / initiator 1155 remote_packet = &setup->sm_s_pres; 1156 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1157 } 1158 1159 // check key size 1160 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1161 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1162 1163 // decide on STK generation method 1164 sm_setup_tk(); 1165 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1166 1167 // check if STK generation method is acceptable by client 1168 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1169 1170 // identical to responder 1171 sm_setup_key_distribution(remote_key_request); 1172 1173 // JUST WORKS doens't provide authentication 1174 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1175 1176 return 0; 1177 } 1178 1179 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1180 1181 // cache and reset context 1182 int matched_device_id = sm_address_resolution_test; 1183 address_resolution_mode_t mode = sm_address_resolution_mode; 1184 void * context = sm_address_resolution_context; 1185 1186 // reset context 1187 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1188 sm_address_resolution_context = NULL; 1189 sm_address_resolution_test = -1; 1190 hci_con_handle_t con_handle = 0; 1191 1192 sm_connection_t * sm_connection; 1193 uint16_t ediv; 1194 switch (mode){ 1195 case ADDRESS_RESOLUTION_GENERAL: 1196 break; 1197 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1198 sm_connection = (sm_connection_t *) context; 1199 con_handle = sm_connection->sm_handle; 1200 switch (event){ 1201 case ADDRESS_RESOLUTION_SUCEEDED: 1202 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1203 sm_connection->sm_le_db_index = matched_device_id; 1204 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1205 if (sm_connection->sm_role) break; 1206 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1207 sm_connection->sm_security_request_received = 0; 1208 sm_connection->sm_bonding_requested = 0; 1209 le_device_db_encryption_get(sm_connection->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 1210 if (ediv){ 1211 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1212 } else { 1213 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1214 } 1215 break; 1216 case ADDRESS_RESOLUTION_FAILED: 1217 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1218 if (sm_connection->sm_role) break; 1219 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1220 sm_connection->sm_security_request_received = 0; 1221 sm_connection->sm_bonding_requested = 0; 1222 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1223 break; 1224 } 1225 break; 1226 default: 1227 break; 1228 } 1229 1230 switch (event){ 1231 case ADDRESS_RESOLUTION_SUCEEDED: 1232 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1233 break; 1234 case ADDRESS_RESOLUTION_FAILED: 1235 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1236 break; 1237 } 1238 } 1239 1240 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1241 1242 int le_db_index = -1; 1243 1244 // lookup device based on IRK 1245 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1246 int i; 1247 for (i=0; i < le_device_db_count(); i++){ 1248 sm_key_t irk; 1249 bd_addr_t address; 1250 int address_type; 1251 le_device_db_info(i, &address_type, address, irk); 1252 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1253 log_info("sm: device found for IRK, updating"); 1254 le_db_index = i; 1255 break; 1256 } 1257 } 1258 } 1259 1260 // if not found, lookup via public address if possible 1261 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1262 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1263 int i; 1264 for (i=0; i < le_device_db_count(); i++){ 1265 bd_addr_t address; 1266 int address_type; 1267 le_device_db_info(i, &address_type, address, NULL); 1268 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1269 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1270 log_info("sm: device found for public address, updating"); 1271 le_db_index = i; 1272 break; 1273 } 1274 } 1275 } 1276 1277 // if not found, add to db 1278 if (le_db_index < 0) { 1279 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1280 } 1281 1282 if (le_db_index >= 0){ 1283 le_device_db_local_counter_set(le_db_index, 0); 1284 1285 // store local CSRK 1286 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1287 log_info("sm: store local CSRK"); 1288 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1289 le_device_db_local_counter_set(le_db_index, 0); 1290 } 1291 1292 // store remote CSRK 1293 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1294 log_info("sm: store remote CSRK"); 1295 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1296 le_device_db_remote_counter_set(le_db_index, 0); 1297 } 1298 1299 // store encryption information 1300 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION 1301 && setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 1302 log_info("sm: set encryption information (key size %u, authenticatd %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1303 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1304 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1305 } 1306 } 1307 1308 // keep le_db_index 1309 sm_conn->sm_le_db_index = le_db_index; 1310 } 1311 1312 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1313 setup->sm_pairing_failed_reason = reason; 1314 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1315 } 1316 1317 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1318 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1319 } 1320 1321 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1322 1323 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1324 static int sm_passkey_used(stk_generation_method_t method); 1325 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1326 1327 static void sm_log_ec_keypair(void){ 1328 log_info("Elliptic curve: d"); 1329 log_info_hexdump(ec_d,32); 1330 log_info("Elliptic curve: X"); 1331 log_info_hexdump(ec_qx,32); 1332 log_info("Elliptic curve: Y"); 1333 log_info_hexdump(ec_qy,32); 1334 } 1335 1336 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1337 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1338 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1339 } else { 1340 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1341 } 1342 } 1343 1344 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1345 if (sm_conn->sm_role){ 1346 // Responder 1347 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1348 } else { 1349 // Initiator role 1350 switch (setup->sm_stk_generation_method){ 1351 case JUST_WORKS: 1352 sm_sc_prepare_dhkey_check(sm_conn); 1353 break; 1354 1355 case NK_BOTH_INPUT: 1356 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1357 break; 1358 case PK_INIT_INPUT: 1359 case PK_RESP_INPUT: 1360 case OK_BOTH_INPUT: 1361 if (setup->sm_passkey_bit < 20) { 1362 sm_sc_start_calculating_local_confirm(sm_conn); 1363 } else { 1364 sm_sc_prepare_dhkey_check(sm_conn); 1365 } 1366 break; 1367 case OOB: 1368 // TODO: implement SC OOB 1369 break; 1370 } 1371 } 1372 } 1373 1374 static uint8_t sm_sc_cmac_get_byte(uint16_t offset){ 1375 return sm_cmac_sc_buffer[offset]; 1376 } 1377 1378 static void sm_sc_cmac_done(uint8_t * hash){ 1379 log_info("sm_sc_cmac_done: "); 1380 log_info_hexdump(hash, 16); 1381 1382 sm_connection_t * sm_conn = sm_cmac_connection; 1383 sm_cmac_connection = NULL; 1384 1385 switch (sm_conn->sm_engine_state){ 1386 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1387 memcpy(setup->sm_local_confirm, hash, 16); 1388 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1389 break; 1390 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1391 // check 1392 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1393 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1394 break; 1395 } 1396 sm_sc_state_after_receiving_random(sm_conn); 1397 break; 1398 case SM_SC_W4_CALCULATE_G2: { 1399 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1400 big_endian_store_32(setup->sm_tk, 12, vab); 1401 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1402 sm_trigger_user_response(sm_conn); 1403 break; 1404 } 1405 case SM_SC_W4_CALCULATE_F5_SALT: 1406 memcpy(setup->sm_t, hash, 16); 1407 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1408 break; 1409 case SM_SC_W4_CALCULATE_F5_MACKEY: 1410 memcpy(setup->sm_mackey, hash, 16); 1411 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1412 break; 1413 case SM_SC_W4_CALCULATE_F5_LTK: 1414 memcpy(setup->sm_ltk, hash, 16); 1415 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1416 break; 1417 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1418 memcpy(setup->sm_local_dhkey_check, hash, 16); 1419 if (sm_conn->sm_role){ 1420 // responder 1421 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1422 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1423 } else { 1424 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1425 } 1426 } else { 1427 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1428 } 1429 break; 1430 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1431 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1432 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1433 break; 1434 } 1435 if (sm_conn->sm_role){ 1436 // responder 1437 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1438 } else { 1439 // initiator 1440 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1441 } 1442 break; 1443 default: 1444 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1445 break; 1446 } 1447 sm_run(); 1448 } 1449 1450 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){ 1451 const uint16_t message_len = 65; 1452 sm_cmac_connection = sm_conn; 1453 memcpy(sm_cmac_sc_buffer, u, 32); 1454 memcpy(sm_cmac_sc_buffer+32, v, 32); 1455 sm_cmac_sc_buffer[64] = z; 1456 log_info("f4 key"); 1457 log_info_hexdump(x, 16); 1458 log_info("f4 message"); 1459 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1460 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1461 } 1462 1463 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1464 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1465 static const uint8_t f5_length[] = { 0x01, 0x00}; 1466 1467 static void sm_sc_calculate_dhkey(sm_key256_t dhkey){ 1468 #ifdef USE_MBEDTLS_FOR_ECDH 1469 // da * Pb 1470 mbedtls_mpi d; 1471 mbedtls_ecp_point Q; 1472 mbedtls_ecp_point DH; 1473 mbedtls_mpi_init(&d); 1474 mbedtls_ecp_point_init(&Q); 1475 mbedtls_ecp_point_init(&DH); 1476 mbedtls_mpi_read_binary(&d, ec_d, 32); 1477 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 1478 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 1479 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 1480 mbedtls_ecp_mul(&mbedtls_ec_group, &DH, &d, &Q, NULL, NULL); 1481 mbedtls_mpi_write_binary(&DH.X, dhkey, 32); 1482 mbedtls_mpi_free(&d); 1483 mbedtls_ecp_point_free(&Q); 1484 mbedtls_ecp_point_free(&DH); 1485 #endif 1486 log_info("dhkey"); 1487 log_info_hexdump(dhkey, 32); 1488 } 1489 1490 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1491 // calculate DHKEY 1492 sm_key256_t dhkey; 1493 sm_sc_calculate_dhkey(dhkey); 1494 1495 // calculate salt for f5 1496 const uint16_t message_len = 32; 1497 sm_cmac_connection = sm_conn; 1498 memcpy(sm_cmac_sc_buffer, dhkey, message_len); 1499 sm_cmac_general_start(f5_salt, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1500 } 1501 1502 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){ 1503 const uint16_t message_len = 53; 1504 sm_cmac_connection = sm_conn; 1505 1506 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1507 sm_cmac_sc_buffer[0] = 0; 1508 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1509 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1510 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1511 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1512 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1513 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1514 log_info("f5 key"); 1515 log_info_hexdump(t, 16); 1516 log_info("f5 message for MacKey"); 1517 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1518 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1519 } 1520 1521 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1522 sm_key56_t bd_addr_master, bd_addr_slave; 1523 bd_addr_master[0] = setup->sm_m_addr_type; 1524 bd_addr_slave[0] = setup->sm_s_addr_type; 1525 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1526 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1527 if (sm_conn->sm_role){ 1528 // responder 1529 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1530 } else { 1531 // initiator 1532 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1533 } 1534 } 1535 1536 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1537 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1538 const uint16_t message_len = 53; 1539 sm_cmac_connection = sm_conn; 1540 sm_cmac_sc_buffer[0] = 1; 1541 // 1..52 setup before 1542 log_info("f5 key"); 1543 log_info_hexdump(t, 16); 1544 log_info("f5 message for LTK"); 1545 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1546 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1547 } 1548 1549 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1550 f5_ltk(sm_conn, setup->sm_t); 1551 } 1552 1553 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){ 1554 const uint16_t message_len = 65; 1555 sm_cmac_connection = sm_conn; 1556 memcpy(sm_cmac_sc_buffer, n1, 16); 1557 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1558 memcpy(sm_cmac_sc_buffer+32, r, 16); 1559 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1560 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1561 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1562 log_info("f6 key"); 1563 log_info_hexdump(w, 16); 1564 log_info("f6 message"); 1565 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1566 sm_cmac_general_start(w, 65, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1567 } 1568 1569 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1570 // - U is 256 bits 1571 // - V is 256 bits 1572 // - X is 128 bits 1573 // - Y is 128 bits 1574 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){ 1575 const uint16_t message_len = 80; 1576 sm_cmac_connection = sm_conn; 1577 memcpy(sm_cmac_sc_buffer, u, 32); 1578 memcpy(sm_cmac_sc_buffer+32, v, 32); 1579 memcpy(sm_cmac_sc_buffer+64, y, 16); 1580 log_info("g2 key"); 1581 log_info_hexdump(x, 16); 1582 log_info("g2 message"); 1583 log_info_hexdump(sm_cmac_sc_buffer, sizeof(sm_cmac_sc_buffer)); 1584 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1585 } 1586 1587 static void g2_calculate(sm_connection_t * sm_conn) { 1588 // calc Va if numeric comparison 1589 if (sm_conn->sm_role){ 1590 // responder 1591 g2_engine(sm_conn, setup->sm_peer_qx, ec_qx, setup->sm_peer_nonce, setup->sm_local_nonce);; 1592 } else { 1593 // initiator 1594 g2_engine(sm_conn, ec_qx, setup->sm_peer_qx, setup->sm_local_nonce, setup->sm_peer_nonce); 1595 } 1596 } 1597 1598 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1599 uint8_t z = 0; 1600 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1601 // some form of passkey 1602 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1603 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1604 setup->sm_passkey_bit++; 1605 } 1606 f4_engine(sm_conn, ec_qx, setup->sm_peer_qx, setup->sm_local_nonce, z); 1607 } 1608 1609 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1610 uint8_t z = 0; 1611 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1612 // some form of passkey 1613 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1614 // sm_passkey_bit was increased before sending confirm value 1615 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1616 } 1617 f4_engine(sm_conn, setup->sm_peer_qx, ec_qx, setup->sm_peer_nonce, z); 1618 } 1619 1620 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1621 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1622 } 1623 1624 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1625 // calculate DHKCheck 1626 sm_key56_t bd_addr_master, bd_addr_slave; 1627 bd_addr_master[0] = setup->sm_m_addr_type; 1628 bd_addr_slave[0] = setup->sm_s_addr_type; 1629 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1630 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1631 uint8_t iocap_a[3]; 1632 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1633 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1634 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1635 uint8_t iocap_b[3]; 1636 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1637 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1638 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1639 if (sm_conn->sm_role){ 1640 // responder 1641 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); 1642 } else { 1643 // initiator 1644 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); 1645 } 1646 } 1647 1648 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1649 // validate E = f6() 1650 sm_key56_t bd_addr_master, bd_addr_slave; 1651 bd_addr_master[0] = setup->sm_m_addr_type; 1652 bd_addr_slave[0] = setup->sm_s_addr_type; 1653 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1654 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1655 1656 uint8_t iocap_a[3]; 1657 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1658 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1659 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1660 uint8_t iocap_b[3]; 1661 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1662 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1663 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1664 if (sm_conn->sm_role){ 1665 // responder 1666 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); 1667 } else { 1668 // initiator 1669 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); 1670 } 1671 } 1672 #endif 1673 1674 static void sm_load_security_info(sm_connection_t * sm_connection){ 1675 int encryption_key_size; 1676 int authenticated; 1677 int authorized; 1678 1679 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1680 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1681 &encryption_key_size, &authenticated, &authorized); 1682 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1683 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1684 sm_connection->sm_connection_authenticated = authenticated; 1685 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1686 } 1687 1688 static void sm_run(void){ 1689 1690 btstack_linked_list_iterator_t it; 1691 1692 // assert that we can send at least commands 1693 if (!hci_can_send_command_packet_now()) return; 1694 1695 // 1696 // non-connection related behaviour 1697 // 1698 1699 // distributed key generation 1700 switch (dkg_state){ 1701 case DKG_CALC_IRK: 1702 // already busy? 1703 if (sm_aes128_state == SM_AES128_IDLE) { 1704 // IRK = d1(IR, 1, 0) 1705 sm_key_t d1_prime; 1706 sm_d1_d_prime(1, 0, d1_prime); // plaintext 1707 dkg_next_state(); 1708 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1709 return; 1710 } 1711 break; 1712 case DKG_CALC_DHK: 1713 // already busy? 1714 if (sm_aes128_state == SM_AES128_IDLE) { 1715 // DHK = d1(IR, 3, 0) 1716 sm_key_t d1_prime; 1717 sm_d1_d_prime(3, 0, d1_prime); // plaintext 1718 dkg_next_state(); 1719 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1720 return; 1721 } 1722 break; 1723 default: 1724 break; 1725 } 1726 1727 #ifdef USE_MBEDTLS_FOR_ECDH 1728 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 1729 sm_random_start(NULL); 1730 return; 1731 } 1732 #endif 1733 1734 // random address updates 1735 switch (rau_state){ 1736 case RAU_GET_RANDOM: 1737 rau_next_state(); 1738 sm_random_start(NULL); 1739 return; 1740 case RAU_GET_ENC: 1741 // already busy? 1742 if (sm_aes128_state == SM_AES128_IDLE) { 1743 sm_key_t r_prime; 1744 sm_ah_r_prime(sm_random_address, r_prime); 1745 rau_next_state(); 1746 sm_aes128_start(sm_persistent_irk, r_prime, NULL); 1747 return; 1748 } 1749 break; 1750 case RAU_SET_ADDRESS: 1751 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1752 rau_state = RAU_IDLE; 1753 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1754 return; 1755 default: 1756 break; 1757 } 1758 1759 // CMAC 1760 switch (sm_cmac_state){ 1761 case CMAC_CALC_SUBKEYS: 1762 case CMAC_CALC_MI: 1763 case CMAC_CALC_MLAST: 1764 // already busy? 1765 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1766 sm_cmac_handle_aes_engine_ready(); 1767 return; 1768 default: 1769 break; 1770 } 1771 1772 // CSRK Lookup 1773 // -- if csrk lookup ready, find connection that require csrk lookup 1774 if (sm_address_resolution_idle()){ 1775 hci_connections_get_iterator(&it); 1776 while(btstack_linked_list_iterator_has_next(&it)){ 1777 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1778 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1779 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1780 // and start lookup 1781 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); 1782 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1783 break; 1784 } 1785 } 1786 } 1787 1788 // -- if csrk lookup ready, resolved addresses for received addresses 1789 if (sm_address_resolution_idle()) { 1790 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1791 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1792 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1793 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1794 btstack_memory_sm_lookup_entry_free(entry); 1795 } 1796 } 1797 1798 // -- Continue with CSRK device lookup by public or resolvable private address 1799 if (!sm_address_resolution_idle()){ 1800 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_count()); 1801 while (sm_address_resolution_test < le_device_db_count()){ 1802 int addr_type; 1803 bd_addr_t addr; 1804 sm_key_t irk; 1805 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1806 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1807 1808 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1809 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1810 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1811 break; 1812 } 1813 1814 if (sm_address_resolution_addr_type == 0){ 1815 sm_address_resolution_test++; 1816 continue; 1817 } 1818 1819 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1820 1821 log_info("LE Device Lookup: calculate AH"); 1822 log_info_key("IRK", irk); 1823 1824 sm_key_t r_prime; 1825 sm_ah_r_prime(sm_address_resolution_address, r_prime); 1826 sm_address_resolution_ah_calculation_active = 1; 1827 sm_aes128_start(irk, r_prime, sm_address_resolution_context); // keep context 1828 return; 1829 } 1830 1831 if (sm_address_resolution_test >= le_device_db_count()){ 1832 log_info("LE Device Lookup: not found"); 1833 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1834 } 1835 } 1836 1837 1838 // 1839 // active connection handling 1840 // -- use loop to handle next connection if lock on setup context is released 1841 1842 while (1) { 1843 1844 // Find connections that requires setup context and make active if no other is locked 1845 hci_connections_get_iterator(&it); 1846 while(!sm_active_connection && btstack_linked_list_iterator_has_next(&it)){ 1847 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1848 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1849 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 1850 int done = 1; 1851 int err; 1852 switch (sm_connection->sm_engine_state) { 1853 case SM_RESPONDER_SEND_SECURITY_REQUEST: 1854 // send packet if possible, 1855 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 1856 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 1857 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 1858 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1859 } else { 1860 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1861 } 1862 // don't lock sxetup context yet 1863 done = 0; 1864 break; 1865 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 1866 sm_init_setup(sm_connection); 1867 // recover pairing request 1868 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 1869 err = sm_stk_generation_init(sm_connection); 1870 if (err){ 1871 setup->sm_pairing_failed_reason = err; 1872 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1873 break; 1874 } 1875 sm_timeout_start(sm_connection); 1876 // generate random number first, if we need to show passkey 1877 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 1878 sm_connection->sm_engine_state = SM_PH2_GET_RANDOM_TK; 1879 break; 1880 } 1881 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 1882 break; 1883 case SM_INITIATOR_PH0_HAS_LTK: 1884 sm_load_security_info(sm_connection); 1885 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 1886 break; 1887 case SM_RESPONDER_PH0_RECEIVED_LTK: 1888 switch (sm_connection->sm_irk_lookup_state){ 1889 case IRK_LOOKUP_SUCCEEDED:{ 1890 sm_load_security_info(sm_connection); 1891 sm_connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 1892 break; 1893 } 1894 case IRK_LOOKUP_FAILED: 1895 // assume that we don't have a LTK for ediv == 0 and random == null 1896 if (sm_connection->sm_local_ediv == 0 && sm_is_null_random(sm_connection->sm_local_rand)){ 1897 log_info("LTK Request: ediv & random are empty"); 1898 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1899 // TODO: no need to lock context yet -> done = 0; 1900 break; 1901 } 1902 // re-establish previously used LTK using Rand and EDIV 1903 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1904 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1905 // re-establish used key encryption size 1906 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1907 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1908 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1909 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1910 log_info("sm: received ltk request with key size %u, authenticated %u", 1911 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1912 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1913 break; 1914 default: 1915 // just wait until IRK lookup is completed 1916 // don't lock sxetup context yet 1917 done = 0; 1918 break; 1919 } 1920 break; 1921 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 1922 sm_init_setup(sm_connection); 1923 sm_timeout_start(sm_connection); 1924 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 1925 break; 1926 default: 1927 done = 0; 1928 break; 1929 } 1930 if (done){ 1931 sm_active_connection = sm_connection->sm_handle; 1932 log_info("sm: connection 0x%04x locked setup context as %s", sm_active_connection, sm_connection->sm_role ? "responder" : "initiator"); 1933 } 1934 } 1935 1936 // 1937 // active connection handling 1938 // 1939 1940 if (sm_active_connection == 0) return; 1941 1942 // assert that we could send a SM PDU - not needed for all of the following 1943 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 1944 l2cap_request_can_send_fix_channel_now_event(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1945 return; 1946 } 1947 1948 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection); 1949 if (!connection) return; 1950 1951 // send keypress notifications 1952 if (setup->sm_keypress_notification != 0xff){ 1953 uint8_t buffer[2]; 1954 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 1955 buffer[1] = setup->sm_keypress_notification; 1956 setup->sm_keypress_notification = 0xff; 1957 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1958 } 1959 1960 sm_key_t plaintext; 1961 int key_distribution_flags; 1962 1963 log_info("sm_run: state %u", connection->sm_engine_state); 1964 1965 // responding state 1966 switch (connection->sm_engine_state){ 1967 1968 // general 1969 case SM_GENERAL_SEND_PAIRING_FAILED: { 1970 uint8_t buffer[2]; 1971 buffer[0] = SM_CODE_PAIRING_FAILED; 1972 buffer[1] = setup->sm_pairing_failed_reason; 1973 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 1974 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1975 sm_done_for_handle(connection->sm_handle); 1976 break; 1977 } 1978 1979 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1980 case SM_SC_W2_GET_RANDOM_A: 1981 sm_random_start(connection); 1982 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_A; 1983 break; 1984 case SM_SC_W2_GET_RANDOM_B: 1985 sm_random_start(connection); 1986 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_B; 1987 break; 1988 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 1989 if (!sm_cmac_ready()) break; 1990 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 1991 sm_sc_calculate_local_confirm(connection); 1992 break; 1993 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 1994 if (!sm_cmac_ready()) break; 1995 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 1996 sm_sc_calculate_remote_confirm(connection); 1997 break; 1998 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 1999 if (!sm_cmac_ready()) break; 2000 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2001 sm_sc_calculate_f6_for_dhkey_check(connection); 2002 break; 2003 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2004 if (!sm_cmac_ready()) break; 2005 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2006 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2007 break; 2008 case SM_SC_W2_CALCULATE_F5_SALT: 2009 if (!sm_cmac_ready()) break; 2010 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2011 f5_calculate_salt(connection); 2012 break; 2013 case SM_SC_W2_CALCULATE_F5_MACKEY: 2014 if (!sm_cmac_ready()) break; 2015 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2016 f5_calculate_mackey(connection); 2017 break; 2018 case SM_SC_W2_CALCULATE_F5_LTK: 2019 if (!sm_cmac_ready()) break; 2020 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2021 f5_calculate_ltk(connection); 2022 break; 2023 case SM_SC_W2_CALCULATE_G2: 2024 if (!sm_cmac_ready()) break; 2025 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2026 g2_calculate(connection); 2027 break; 2028 2029 #endif 2030 // initiator side 2031 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2032 sm_key_t peer_ltk_flipped; 2033 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2034 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2035 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2036 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2037 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2038 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2039 return; 2040 } 2041 2042 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2043 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2044 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2045 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2046 sm_timeout_reset(connection); 2047 break; 2048 2049 // responder side 2050 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2051 connection->sm_engine_state = SM_RESPONDER_IDLE; 2052 hci_send_cmd(&hci_le_long_term_key_negative_reply, connection->sm_handle); 2053 sm_done_for_handle(connection->sm_handle); 2054 return; 2055 2056 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2057 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2058 uint8_t buffer[65]; 2059 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2060 // 2061 reverse_256(ec_qx, &buffer[1]); 2062 reverse_256(ec_qy, &buffer[33]); 2063 2064 // stk generation method 2065 // passkey entry: notify app to show passkey or to request passkey 2066 switch (setup->sm_stk_generation_method){ 2067 case JUST_WORKS: 2068 case NK_BOTH_INPUT: 2069 if (connection->sm_role){ 2070 // responder 2071 sm_sc_start_calculating_local_confirm(connection); 2072 } else { 2073 // initiator 2074 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2075 } 2076 break; 2077 case PK_INIT_INPUT: 2078 case PK_RESP_INPUT: 2079 case OK_BOTH_INPUT: 2080 // use random TK for display 2081 memcpy(setup->sm_ra, setup->sm_tk, 16); 2082 memcpy(setup->sm_rb, setup->sm_tk, 16); 2083 setup->sm_passkey_bit = 0; 2084 2085 if (connection->sm_role){ 2086 // responder 2087 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2088 } else { 2089 // initiator 2090 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2091 } 2092 sm_trigger_user_response(connection); 2093 break; 2094 case OOB: 2095 // TODO: implement SC OOB 2096 break; 2097 } 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_CONFIRMATION: { 2104 uint8_t buffer[17]; 2105 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2106 reverse_128(setup->sm_local_confirm, &buffer[1]); 2107 if (connection->sm_role){ 2108 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2109 } else { 2110 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2111 } 2112 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2113 sm_timeout_reset(connection); 2114 break; 2115 } 2116 case SM_SC_SEND_PAIRING_RANDOM: { 2117 uint8_t buffer[17]; 2118 buffer[0] = SM_CODE_PAIRING_RANDOM; 2119 reverse_128(setup->sm_local_nonce, &buffer[1]); 2120 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT && setup->sm_passkey_bit < 20){ 2121 if (connection->sm_role){ 2122 // responder 2123 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2124 } else { 2125 // initiator 2126 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2127 } 2128 } else { 2129 if (connection->sm_role){ 2130 // responder 2131 if (setup->sm_stk_generation_method == NK_BOTH_INPUT){ 2132 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2133 } else { 2134 sm_sc_prepare_dhkey_check(connection); 2135 } 2136 } else { 2137 // initiator 2138 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2139 } 2140 } 2141 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2142 sm_timeout_reset(connection); 2143 break; 2144 } 2145 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2146 uint8_t buffer[17]; 2147 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2148 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2149 2150 if (connection->sm_role){ 2151 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2152 } else { 2153 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2154 } 2155 2156 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2157 sm_timeout_reset(connection); 2158 break; 2159 } 2160 2161 #endif 2162 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2163 // echo initiator for now 2164 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2165 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2166 2167 if (setup->sm_use_secure_connections){ 2168 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2169 // skip LTK/EDIV for SC 2170 log_info("sm: dropping encryption information flag"); 2171 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2172 } else { 2173 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2174 } 2175 2176 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); 2177 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); 2178 // update key distribution after ENC was dropped 2179 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2180 2181 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2182 sm_timeout_reset(connection); 2183 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2184 if (!setup->sm_use_secure_connections || setup->sm_stk_generation_method == JUST_WORKS){ 2185 sm_trigger_user_response(connection); 2186 } 2187 return; 2188 2189 case SM_PH2_SEND_PAIRING_RANDOM: { 2190 uint8_t buffer[17]; 2191 buffer[0] = SM_CODE_PAIRING_RANDOM; 2192 reverse_128(setup->sm_local_random, &buffer[1]); 2193 if (connection->sm_role){ 2194 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2195 } else { 2196 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2197 } 2198 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2199 sm_timeout_reset(connection); 2200 break; 2201 } 2202 2203 case SM_PH2_GET_RANDOM_TK: 2204 case SM_PH2_C1_GET_RANDOM_A: 2205 case SM_PH2_C1_GET_RANDOM_B: 2206 case SM_PH3_GET_RANDOM: 2207 case SM_PH3_GET_DIV: 2208 sm_next_responding_state(connection); 2209 sm_random_start(connection); 2210 return; 2211 2212 case SM_PH2_C1_GET_ENC_B: 2213 case SM_PH2_C1_GET_ENC_D: 2214 // already busy? 2215 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2216 sm_next_responding_state(connection); 2217 sm_aes128_start(setup->sm_tk, setup->sm_c1_t3_value, connection); 2218 return; 2219 2220 case SM_PH3_LTK_GET_ENC: 2221 case SM_RESPONDER_PH4_LTK_GET_ENC: 2222 // already busy? 2223 if (sm_aes128_state == SM_AES128_IDLE) { 2224 sm_key_t d_prime; 2225 sm_d1_d_prime(setup->sm_local_div, 0, d_prime); 2226 sm_next_responding_state(connection); 2227 sm_aes128_start(sm_persistent_er, d_prime, connection); 2228 return; 2229 } 2230 break; 2231 2232 case SM_PH3_CSRK_GET_ENC: 2233 // already busy? 2234 if (sm_aes128_state == SM_AES128_IDLE) { 2235 sm_key_t d_prime; 2236 sm_d1_d_prime(setup->sm_local_div, 1, d_prime); 2237 sm_next_responding_state(connection); 2238 sm_aes128_start(sm_persistent_er, d_prime, connection); 2239 return; 2240 } 2241 break; 2242 2243 case SM_PH2_C1_GET_ENC_C: 2244 // already busy? 2245 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2246 // calculate m_confirm using aes128 engine - step 1 2247 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); 2248 sm_next_responding_state(connection); 2249 sm_aes128_start(setup->sm_tk, plaintext, connection); 2250 break; 2251 case SM_PH2_C1_GET_ENC_A: 2252 // already busy? 2253 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2254 // calculate confirm using aes128 engine - step 1 2255 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); 2256 sm_next_responding_state(connection); 2257 sm_aes128_start(setup->sm_tk, plaintext, connection); 2258 break; 2259 case SM_PH2_CALC_STK: 2260 // already busy? 2261 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2262 // calculate STK 2263 if (connection->sm_role){ 2264 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, plaintext); 2265 } else { 2266 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, plaintext); 2267 } 2268 sm_next_responding_state(connection); 2269 sm_aes128_start(setup->sm_tk, plaintext, connection); 2270 break; 2271 case SM_PH3_Y_GET_ENC: 2272 // already busy? 2273 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2274 // PH3B2 - calculate Y from - enc 2275 // Y = dm(DHK, Rand) 2276 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2277 sm_next_responding_state(connection); 2278 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2279 return; 2280 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2281 uint8_t buffer[17]; 2282 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2283 reverse_128(setup->sm_local_confirm, &buffer[1]); 2284 if (connection->sm_role){ 2285 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2286 } else { 2287 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2288 } 2289 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2290 sm_timeout_reset(connection); 2291 return; 2292 } 2293 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2294 sm_key_t stk_flipped; 2295 reverse_128(setup->sm_ltk, stk_flipped); 2296 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2297 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2298 return; 2299 } 2300 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2301 sm_key_t stk_flipped; 2302 reverse_128(setup->sm_ltk, stk_flipped); 2303 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2304 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2305 return; 2306 } 2307 case SM_RESPONDER_PH4_SEND_LTK: { 2308 sm_key_t ltk_flipped; 2309 reverse_128(setup->sm_ltk, ltk_flipped); 2310 connection->sm_engine_state = SM_RESPONDER_IDLE; 2311 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2312 return; 2313 } 2314 case SM_RESPONDER_PH4_Y_GET_ENC: 2315 // already busy? 2316 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2317 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2318 // Y = dm(DHK, Rand) 2319 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2320 sm_next_responding_state(connection); 2321 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2322 return; 2323 2324 case SM_PH3_DISTRIBUTE_KEYS: 2325 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2326 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2327 uint8_t buffer[17]; 2328 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2329 reverse_128(setup->sm_ltk, &buffer[1]); 2330 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2331 sm_timeout_reset(connection); 2332 return; 2333 } 2334 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2335 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2336 uint8_t buffer[11]; 2337 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2338 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2339 reverse_64(setup->sm_local_rand, &buffer[3]); 2340 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2341 sm_timeout_reset(connection); 2342 return; 2343 } 2344 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2345 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2346 uint8_t buffer[17]; 2347 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2348 reverse_128(sm_persistent_irk, &buffer[1]); 2349 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2350 sm_timeout_reset(connection); 2351 return; 2352 } 2353 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2354 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2355 bd_addr_t local_address; 2356 uint8_t buffer[8]; 2357 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2358 gap_advertisements_get_address(&buffer[1], local_address); 2359 reverse_bd_addr(local_address, &buffer[2]); 2360 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2361 sm_timeout_reset(connection); 2362 return; 2363 } 2364 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2365 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2366 2367 // hack to reproduce test runs 2368 if (test_use_fixed_local_csrk){ 2369 memset(setup->sm_local_csrk, 0xcc, 16); 2370 } 2371 2372 uint8_t buffer[17]; 2373 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2374 reverse_128(setup->sm_local_csrk, &buffer[1]); 2375 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2376 sm_timeout_reset(connection); 2377 return; 2378 } 2379 2380 // keys are sent 2381 if (connection->sm_role){ 2382 // slave -> receive master keys if any 2383 if (sm_key_distribution_all_received(connection)){ 2384 sm_key_distribution_handle_all_received(connection); 2385 connection->sm_engine_state = SM_RESPONDER_IDLE; 2386 sm_done_for_handle(connection->sm_handle); 2387 } else { 2388 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2389 } 2390 } else { 2391 // master -> all done 2392 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2393 sm_done_for_handle(connection->sm_handle); 2394 } 2395 break; 2396 2397 default: 2398 break; 2399 } 2400 2401 // check again if active connection was released 2402 if (sm_active_connection) break; 2403 } 2404 } 2405 2406 // note: aes engine is ready as we just got the aes result 2407 static void sm_handle_encryption_result(uint8_t * data){ 2408 2409 sm_aes128_state = SM_AES128_IDLE; 2410 2411 if (sm_address_resolution_ah_calculation_active){ 2412 sm_address_resolution_ah_calculation_active = 0; 2413 // compare calulated address against connecting device 2414 uint8_t hash[3]; 2415 reverse_24(data, hash); 2416 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2417 log_info("LE Device Lookup: matched resolvable private address"); 2418 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2419 return; 2420 } 2421 // no match, try next 2422 sm_address_resolution_test++; 2423 return; 2424 } 2425 2426 switch (dkg_state){ 2427 case DKG_W4_IRK: 2428 reverse_128(data, sm_persistent_irk); 2429 log_info_key("irk", sm_persistent_irk); 2430 dkg_next_state(); 2431 return; 2432 case DKG_W4_DHK: 2433 reverse_128(data, sm_persistent_dhk); 2434 log_info_key("dhk", sm_persistent_dhk); 2435 dkg_next_state(); 2436 // SM Init Finished 2437 return; 2438 default: 2439 break; 2440 } 2441 2442 switch (rau_state){ 2443 case RAU_W4_ENC: 2444 reverse_24(data, &sm_random_address[3]); 2445 rau_next_state(); 2446 return; 2447 default: 2448 break; 2449 } 2450 2451 switch (sm_cmac_state){ 2452 case CMAC_W4_SUBKEYS: 2453 case CMAC_W4_MI: 2454 case CMAC_W4_MLAST: 2455 { 2456 sm_key_t t; 2457 reverse_128(data, t); 2458 sm_cmac_handle_encryption_result(t); 2459 } 2460 return; 2461 default: 2462 break; 2463 } 2464 2465 // retrieve sm_connection provided to sm_aes128_start_encryption 2466 sm_connection_t * connection = (sm_connection_t*) sm_aes128_context; 2467 if (!connection) return; 2468 switch (connection->sm_engine_state){ 2469 case SM_PH2_C1_W4_ENC_A: 2470 case SM_PH2_C1_W4_ENC_C: 2471 { 2472 sm_key_t t2; 2473 reverse_128(data, t2); 2474 sm_c1_t3(t2, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2475 } 2476 sm_next_responding_state(connection); 2477 return; 2478 case SM_PH2_C1_W4_ENC_B: 2479 reverse_128(data, setup->sm_local_confirm); 2480 log_info_key("c1!", setup->sm_local_confirm); 2481 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2482 return; 2483 case SM_PH2_C1_W4_ENC_D: 2484 { 2485 sm_key_t peer_confirm_test; 2486 reverse_128(data, peer_confirm_test); 2487 log_info_key("c1!", peer_confirm_test); 2488 if (memcmp(setup->sm_peer_confirm, peer_confirm_test, 16) != 0){ 2489 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2490 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2491 return; 2492 } 2493 if (connection->sm_role){ 2494 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2495 } else { 2496 connection->sm_engine_state = SM_PH2_CALC_STK; 2497 } 2498 } 2499 return; 2500 case SM_PH2_W4_STK: 2501 reverse_128(data, setup->sm_ltk); 2502 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2503 log_info_key("stk", setup->sm_ltk); 2504 if (connection->sm_role){ 2505 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2506 } else { 2507 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2508 } 2509 return; 2510 case SM_PH3_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 // PH3B3 - calculate EDIV 2516 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2517 log_info_hex16("ediv", setup->sm_local_ediv); 2518 // PH3B4 - calculate LTK - enc 2519 // LTK = d1(ER, DIV, 0)) 2520 connection->sm_engine_state = SM_PH3_LTK_GET_ENC; 2521 return; 2522 } 2523 case SM_RESPONDER_PH4_Y_W4_ENC:{ 2524 sm_key_t y128; 2525 reverse_128(data, y128); 2526 setup->sm_local_y = big_endian_read_16(y128, 14); 2527 log_info_hex16("y", setup->sm_local_y); 2528 2529 // PH3B3 - calculate DIV 2530 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2531 log_info_hex16("ediv", setup->sm_local_ediv); 2532 // PH3B4 - calculate LTK - enc 2533 // LTK = d1(ER, DIV, 0)) 2534 connection->sm_engine_state = SM_RESPONDER_PH4_LTK_GET_ENC; 2535 return; 2536 } 2537 case SM_PH3_LTK_W4_ENC: 2538 reverse_128(data, setup->sm_ltk); 2539 log_info_key("ltk", setup->sm_ltk); 2540 // calc CSRK next 2541 connection->sm_engine_state = SM_PH3_CSRK_GET_ENC; 2542 return; 2543 case SM_PH3_CSRK_W4_ENC: 2544 reverse_128(data, setup->sm_local_csrk); 2545 log_info_key("csrk", setup->sm_local_csrk); 2546 if (setup->sm_key_distribution_send_set){ 2547 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2548 } else { 2549 // no keys to send, just continue 2550 if (connection->sm_role){ 2551 // slave -> receive master keys 2552 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2553 } else { 2554 // master -> all done 2555 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2556 sm_done_for_handle(connection->sm_handle); 2557 } 2558 } 2559 return; 2560 case SM_RESPONDER_PH4_LTK_W4_ENC: 2561 reverse_128(data, setup->sm_ltk); 2562 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2563 log_info_key("ltk", setup->sm_ltk); 2564 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK; 2565 return; 2566 default: 2567 break; 2568 } 2569 } 2570 2571 #ifdef USE_MBEDTLS_FOR_ECDH 2572 2573 static int sm_generate_f_rng(void * context, unsigned char * buffer, size_t size){ 2574 int offset = setup->sm_passkey_bit; 2575 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, offset); 2576 while (size) { 2577 if (offset < 32){ 2578 *buffer++ = setup->sm_peer_qx[offset++]; 2579 } else { 2580 *buffer++ = setup->sm_peer_qx[offset++ - 32]; 2581 } 2582 size--; 2583 } 2584 setup->sm_passkey_bit = offset; 2585 return 0; 2586 } 2587 #endif 2588 2589 // note: random generator is ready. this doesn NOT imply that aes engine is unused! 2590 static void sm_handle_random_result(uint8_t * data){ 2591 2592 #ifdef USE_MBEDTLS_FOR_ECDH 2593 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 2594 int num_bytes = setup->sm_passkey_bit; 2595 if (num_bytes < 32){ 2596 memcpy(&setup->sm_peer_qx[num_bytes], data, 8); 2597 } else { 2598 memcpy(&setup->sm_peer_qx[num_bytes-32], data, 8); 2599 } 2600 num_bytes += 8; 2601 setup->sm_passkey_bit = num_bytes; 2602 2603 if (num_bytes >= 64){ 2604 // generate EC key 2605 setup->sm_passkey_bit = 0; 2606 mbedtls_mpi d; 2607 mbedtls_ecp_point P; 2608 mbedtls_mpi_init(&d); 2609 mbedtls_ecp_point_init(&P); 2610 int res = mbedtls_ecp_gen_keypair(&mbedtls_ec_group, &d, &P, &sm_generate_f_rng, NULL); 2611 log_info("gen keypair %x", res); 2612 mbedtls_mpi_write_binary(&P.X, ec_qx, 32); 2613 mbedtls_mpi_write_binary(&P.Y, ec_qy, 32); 2614 mbedtls_mpi_write_binary(&d, ec_d, 32); 2615 mbedtls_ecp_point_free(&P); 2616 mbedtls_mpi_free(&d); 2617 ec_key_generation_state = EC_KEY_GENERATION_DONE; 2618 sm_log_ec_keypair(); 2619 2620 #if 0 2621 printf("test dhkey check\n"); 2622 sm_key256_t dhkey; 2623 memcpy(setup->sm_peer_qx, ec_qx, 32); 2624 memcpy(setup->sm_peer_qy, ec_qy, 32); 2625 sm_sc_calculate_dhkey(dhkey); 2626 #endif 2627 2628 } 2629 } 2630 #endif 2631 2632 switch (rau_state){ 2633 case RAU_W4_RANDOM: 2634 // non-resolvable vs. resolvable 2635 switch (gap_random_adress_type){ 2636 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2637 // resolvable: use random as prand and calc address hash 2638 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2639 memcpy(sm_random_address, data, 3); 2640 sm_random_address[0] &= 0x3f; 2641 sm_random_address[0] |= 0x40; 2642 rau_state = RAU_GET_ENC; 2643 break; 2644 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2645 default: 2646 // "The two most significant bits of the address shall be equal to ‘0’"" 2647 memcpy(sm_random_address, data, 6); 2648 sm_random_address[0] &= 0x3f; 2649 rau_state = RAU_SET_ADDRESS; 2650 break; 2651 } 2652 return; 2653 default: 2654 break; 2655 } 2656 2657 // retrieve sm_connection provided to sm_random_start 2658 sm_connection_t * connection = (sm_connection_t *) sm_random_context; 2659 if (!connection) return; 2660 switch (connection->sm_engine_state){ 2661 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2662 case SM_SC_W4_GET_RANDOM_A: 2663 memcpy(&setup->sm_local_nonce[0], data, 8); 2664 connection->sm_engine_state = SM_SC_W2_GET_RANDOM_B; 2665 break; 2666 case SM_SC_W4_GET_RANDOM_B: 2667 memcpy(&setup->sm_local_nonce[8], data, 8); 2668 // initiator & jw/nc -> send pairing random 2669 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2670 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2671 break; 2672 } else { 2673 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2674 } 2675 break; 2676 #endif 2677 2678 case SM_PH2_W4_RANDOM_TK: 2679 { 2680 // map random to 0-999999 without speding much cycles on a modulus operation 2681 uint32_t tk = little_endian_read_32(data,0); 2682 tk = tk & 0xfffff; // 1048575 2683 if (tk >= 999999){ 2684 tk = tk - 999999; 2685 } 2686 sm_reset_tk(); 2687 big_endian_store_32(setup->sm_tk, 12, tk); 2688 if (connection->sm_role){ 2689 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2690 } else { 2691 if (setup->sm_use_secure_connections){ 2692 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 2693 } else { 2694 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2695 sm_trigger_user_response(connection); 2696 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2697 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2698 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 2699 } 2700 } 2701 } 2702 return; 2703 } 2704 case SM_PH2_C1_W4_RANDOM_A: 2705 memcpy(&setup->sm_local_random[0], data, 8); // random endinaness 2706 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_B; 2707 return; 2708 case SM_PH2_C1_W4_RANDOM_B: 2709 memcpy(&setup->sm_local_random[8], data, 8); // random endinaness 2710 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2711 return; 2712 case SM_PH3_W4_RANDOM: 2713 reverse_64(data, setup->sm_local_rand); 2714 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2715 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2716 // no db for authenticated flag hack: store flag in bit 4 of LSB 2717 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2718 connection->sm_engine_state = SM_PH3_GET_DIV; 2719 return; 2720 case SM_PH3_W4_DIV: 2721 // use 16 bit from random value as div 2722 setup->sm_local_div = big_endian_read_16(data, 0); 2723 log_info_hex16("div", setup->sm_local_div); 2724 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2725 return; 2726 default: 2727 break; 2728 } 2729 } 2730 2731 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2732 2733 sm_connection_t * sm_conn; 2734 hci_con_handle_t con_handle; 2735 2736 switch (packet_type) { 2737 2738 case HCI_EVENT_PACKET: 2739 switch (hci_event_packet_get_type(packet)) { 2740 2741 case BTSTACK_EVENT_STATE: 2742 // bt stack activated, get started 2743 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2744 log_info("HCI Working!"); 2745 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 2746 rau_state = RAU_IDLE; 2747 #ifdef USE_MBEDTLS_FOR_ECDH 2748 if (!sm_have_ec_keypair){ 2749 setup->sm_passkey_bit = 0; 2750 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 2751 } 2752 #endif 2753 sm_run(); 2754 } 2755 break; 2756 2757 case HCI_EVENT_LE_META: 2758 switch (packet[2]) { 2759 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2760 2761 log_info("sm: connected"); 2762 2763 if (packet[3]) return; // connection failed 2764 2765 con_handle = little_endian_read_16(packet, 4); 2766 sm_conn = sm_get_connection_for_handle(con_handle); 2767 if (!sm_conn) break; 2768 2769 sm_conn->sm_handle = con_handle; 2770 sm_conn->sm_role = packet[6]; 2771 sm_conn->sm_peer_addr_type = packet[7]; 2772 reverse_bd_addr(&packet[8], 2773 sm_conn->sm_peer_address); 2774 2775 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2776 2777 // reset security properties 2778 sm_conn->sm_connection_encrypted = 0; 2779 sm_conn->sm_connection_authenticated = 0; 2780 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2781 sm_conn->sm_le_db_index = -1; 2782 2783 // prepare CSRK lookup (does not involve setup) 2784 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2785 2786 // just connected -> everything else happens in sm_run() 2787 if (sm_conn->sm_role){ 2788 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2789 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2790 if (sm_slave_request_security) { 2791 // request security if requested by app 2792 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2793 } else { 2794 // otherwise, wait for pairing request 2795 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2796 } 2797 } 2798 break; 2799 } else { 2800 // master 2801 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2802 } 2803 break; 2804 2805 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2806 con_handle = little_endian_read_16(packet, 3); 2807 sm_conn = sm_get_connection_for_handle(con_handle); 2808 if (!sm_conn) break; 2809 2810 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2811 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2812 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2813 break; 2814 } 2815 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 2816 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2817 break; 2818 } 2819 2820 // store rand and ediv 2821 reverse_64(&packet[5], sm_conn->sm_local_rand); 2822 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2823 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK; 2824 break; 2825 2826 default: 2827 break; 2828 } 2829 break; 2830 2831 case HCI_EVENT_ENCRYPTION_CHANGE: 2832 con_handle = little_endian_read_16(packet, 3); 2833 sm_conn = sm_get_connection_for_handle(con_handle); 2834 if (!sm_conn) break; 2835 2836 sm_conn->sm_connection_encrypted = packet[5]; 2837 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 2838 sm_conn->sm_actual_encryption_key_size); 2839 log_info("event handler, state %u", sm_conn->sm_engine_state); 2840 if (!sm_conn->sm_connection_encrypted) break; 2841 // continue if part of initial pairing 2842 switch (sm_conn->sm_engine_state){ 2843 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2844 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2845 sm_done_for_handle(sm_conn->sm_handle); 2846 break; 2847 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2848 if (sm_conn->sm_role){ 2849 // slave 2850 if (setup->sm_use_secure_connections){ 2851 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2852 } else { 2853 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2854 } 2855 } else { 2856 // master 2857 if (sm_key_distribution_all_received(sm_conn)){ 2858 // skip receiving keys as there are none 2859 sm_key_distribution_handle_all_received(sm_conn); 2860 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2861 } else { 2862 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2863 } 2864 } 2865 break; 2866 default: 2867 break; 2868 } 2869 break; 2870 2871 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 2872 con_handle = little_endian_read_16(packet, 3); 2873 sm_conn = sm_get_connection_for_handle(con_handle); 2874 if (!sm_conn) break; 2875 2876 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 2877 log_info("event handler, state %u", sm_conn->sm_engine_state); 2878 // continue if part of initial pairing 2879 switch (sm_conn->sm_engine_state){ 2880 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2881 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2882 sm_done_for_handle(sm_conn->sm_handle); 2883 break; 2884 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2885 if (sm_conn->sm_role){ 2886 // slave 2887 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2888 } else { 2889 // master 2890 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2891 } 2892 break; 2893 default: 2894 break; 2895 } 2896 break; 2897 2898 2899 case HCI_EVENT_DISCONNECTION_COMPLETE: 2900 con_handle = little_endian_read_16(packet, 3); 2901 sm_done_for_handle(con_handle); 2902 sm_conn = sm_get_connection_for_handle(con_handle); 2903 if (!sm_conn) break; 2904 2905 // delete stored bonding on disconnect with authentication failure in ph0 2906 if (sm_conn->sm_role == 0 2907 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 2908 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 2909 le_device_db_remove(sm_conn->sm_le_db_index); 2910 } 2911 2912 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 2913 sm_conn->sm_handle = 0; 2914 break; 2915 2916 case HCI_EVENT_COMMAND_COMPLETE: 2917 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 2918 sm_handle_encryption_result(&packet[6]); 2919 break; 2920 } 2921 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 2922 sm_handle_random_result(&packet[6]); 2923 break; 2924 } 2925 break; 2926 default: 2927 break; 2928 } 2929 break; 2930 default: 2931 break; 2932 } 2933 2934 sm_run(); 2935 } 2936 2937 static inline int sm_calc_actual_encryption_key_size(int other){ 2938 if (other < sm_min_encryption_key_size) return 0; 2939 if (other < sm_max_encryption_key_size) return other; 2940 return sm_max_encryption_key_size; 2941 } 2942 2943 2944 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2945 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 2946 switch (method){ 2947 case JUST_WORKS: 2948 case NK_BOTH_INPUT: 2949 return 1; 2950 default: 2951 return 0; 2952 } 2953 } 2954 // responder 2955 2956 static int sm_passkey_used(stk_generation_method_t method){ 2957 switch (method){ 2958 case PK_RESP_INPUT: 2959 return 1; 2960 default: 2961 return 0; 2962 } 2963 } 2964 #endif 2965 2966 /** 2967 * @return ok 2968 */ 2969 static int sm_validate_stk_generation_method(void){ 2970 // check if STK generation method is acceptable by client 2971 switch (setup->sm_stk_generation_method){ 2972 case JUST_WORKS: 2973 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 2974 case PK_RESP_INPUT: 2975 case PK_INIT_INPUT: 2976 case OK_BOTH_INPUT: 2977 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 2978 case OOB: 2979 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 2980 case NK_BOTH_INPUT: 2981 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 2982 return 1; 2983 default: 2984 return 0; 2985 } 2986 } 2987 2988 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 2989 2990 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 2991 sm_run(); 2992 } 2993 2994 if (packet_type != SM_DATA_PACKET) return; 2995 2996 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 2997 if (!sm_conn) return; 2998 2999 if (packet[0] == SM_CODE_PAIRING_FAILED){ 3000 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3001 return; 3002 } 3003 3004 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, packet[0]); 3005 3006 int err; 3007 3008 if (packet[0] == SM_CODE_KEYPRESS_NOTIFICATION){ 3009 uint8_t buffer[5]; 3010 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3011 buffer[1] = 3; 3012 little_endian_store_16(buffer, 2, con_handle); 3013 buffer[4] = packet[1]; 3014 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3015 return; 3016 } 3017 3018 switch (sm_conn->sm_engine_state){ 3019 3020 // a sm timeout requries a new physical connection 3021 case SM_GENERAL_TIMEOUT: 3022 return; 3023 3024 // Initiator 3025 case SM_INITIATOR_CONNECTED: 3026 if ((packet[0] != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3027 sm_pdu_received_in_wrong_state(sm_conn); 3028 break; 3029 } 3030 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 3031 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3032 break; 3033 } 3034 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 3035 uint16_t ediv; 3036 sm_key_t ltk; 3037 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3038 if (!sm_is_null_key(ltk) || ediv){ 3039 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3040 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3041 } else { 3042 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3043 } 3044 break; 3045 } 3046 // otherwise, store security request 3047 sm_conn->sm_security_request_received = 1; 3048 break; 3049 3050 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3051 if (packet[0] != SM_CODE_PAIRING_RESPONSE){ 3052 sm_pdu_received_in_wrong_state(sm_conn); 3053 break; 3054 } 3055 // store pairing request 3056 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3057 err = sm_stk_generation_init(sm_conn); 3058 if (err){ 3059 setup->sm_pairing_failed_reason = err; 3060 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3061 break; 3062 } 3063 3064 // generate random number first, if we need to show passkey 3065 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3066 sm_conn->sm_engine_state = SM_PH2_GET_RANDOM_TK; 3067 break; 3068 } 3069 3070 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3071 if (setup->sm_use_secure_connections){ 3072 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3073 if (setup->sm_stk_generation_method == JUST_WORKS){ 3074 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3075 sm_trigger_user_response(sm_conn); 3076 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3077 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3078 } 3079 } else { 3080 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3081 } 3082 break; 3083 } 3084 #endif 3085 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3086 sm_trigger_user_response(sm_conn); 3087 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3088 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3089 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3090 } 3091 break; 3092 3093 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3094 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3095 sm_pdu_received_in_wrong_state(sm_conn); 3096 break; 3097 } 3098 3099 // store s_confirm 3100 reverse_128(&packet[1], setup->sm_peer_confirm); 3101 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3102 break; 3103 3104 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3105 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3106 sm_pdu_received_in_wrong_state(sm_conn); 3107 break;; 3108 } 3109 3110 // received random value 3111 reverse_128(&packet[1], setup->sm_peer_random); 3112 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3113 break; 3114 3115 // Responder 3116 case SM_RESPONDER_IDLE: 3117 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3118 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3119 if (packet[0] != SM_CODE_PAIRING_REQUEST){ 3120 sm_pdu_received_in_wrong_state(sm_conn); 3121 break;; 3122 } 3123 3124 // store pairing request 3125 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3126 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3127 break; 3128 3129 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3130 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3131 if (packet[0] != SM_CODE_PAIRING_PUBLIC_KEY){ 3132 sm_pdu_received_in_wrong_state(sm_conn); 3133 break; 3134 } 3135 3136 // store public key for DH Key calculation 3137 reverse_256(&packet[01], setup->sm_peer_qx); 3138 reverse_256(&packet[33], setup->sm_peer_qy); 3139 3140 #ifdef USE_MBEDTLS_FOR_ECDH 3141 // validate public key 3142 mbedtls_ecp_point Q; 3143 mbedtls_ecp_point_init( &Q ); 3144 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 3145 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 3146 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 3147 err = mbedtls_ecp_check_pubkey(&mbedtls_ec_group, &Q); 3148 mbedtls_ecp_point_free( & Q); 3149 if (err){ 3150 log_error("sm: peer public key invalid %x", err); 3151 // uses "unspecified reason", there is no "public key invalid" error code 3152 sm_pdu_received_in_wrong_state(sm_conn); 3153 break; 3154 } 3155 3156 #endif 3157 if (sm_conn->sm_role){ 3158 // responder 3159 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3160 } else { 3161 // initiator 3162 // stk generation method 3163 // passkey entry: notify app to show passkey or to request passkey 3164 switch (setup->sm_stk_generation_method){ 3165 case JUST_WORKS: 3166 case NK_BOTH_INPUT: 3167 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3168 break; 3169 case PK_RESP_INPUT: 3170 sm_sc_start_calculating_local_confirm(sm_conn); 3171 break; 3172 case PK_INIT_INPUT: 3173 case OK_BOTH_INPUT: 3174 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3175 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3176 break; 3177 } 3178 sm_sc_start_calculating_local_confirm(sm_conn); 3179 break; 3180 case OOB: 3181 // TODO: implement SC OOB 3182 break; 3183 } 3184 } 3185 break; 3186 3187 case SM_SC_W4_CONFIRMATION: 3188 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3189 sm_pdu_received_in_wrong_state(sm_conn); 3190 break; 3191 } 3192 // received confirm value 3193 reverse_128(&packet[1], setup->sm_peer_confirm); 3194 3195 if (sm_conn->sm_role){ 3196 // responder 3197 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3198 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3199 // still waiting for passkey 3200 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3201 break; 3202 } 3203 } 3204 sm_sc_start_calculating_local_confirm(sm_conn); 3205 } else { 3206 // initiator 3207 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3208 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3209 } else { 3210 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3211 } 3212 } 3213 break; 3214 3215 case SM_SC_W4_PAIRING_RANDOM: 3216 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3217 sm_pdu_received_in_wrong_state(sm_conn); 3218 break; 3219 } 3220 3221 // received random value 3222 reverse_128(&packet[1], setup->sm_peer_nonce); 3223 3224 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3225 // only check for JUST WORK/NC in initiator role AND passkey entry 3226 if (sm_conn->sm_role || sm_passkey_used(setup->sm_stk_generation_method)) { 3227 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3228 } 3229 3230 sm_sc_state_after_receiving_random(sm_conn); 3231 break; 3232 3233 case SM_SC_W2_CALCULATE_G2: 3234 case SM_SC_W4_CALCULATE_G2: 3235 case SM_SC_W2_CALCULATE_F5_SALT: 3236 case SM_SC_W4_CALCULATE_F5_SALT: 3237 case SM_SC_W2_CALCULATE_F5_MACKEY: 3238 case SM_SC_W4_CALCULATE_F5_MACKEY: 3239 case SM_SC_W2_CALCULATE_F5_LTK: 3240 case SM_SC_W4_CALCULATE_F5_LTK: 3241 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3242 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3243 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3244 if (packet[0] != SM_CODE_PAIRING_DHKEY_CHECK){ 3245 sm_pdu_received_in_wrong_state(sm_conn); 3246 break; 3247 } 3248 // store DHKey Check 3249 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3250 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3251 3252 // have we been only waiting for dhkey check command? 3253 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3254 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3255 } 3256 break; 3257 #endif 3258 3259 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3260 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3261 sm_pdu_received_in_wrong_state(sm_conn); 3262 break; 3263 } 3264 3265 // received confirm value 3266 reverse_128(&packet[1], setup->sm_peer_confirm); 3267 3268 // notify client to hide shown passkey 3269 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3270 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3271 } 3272 3273 // handle user cancel pairing? 3274 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3275 setup->sm_pairing_failed_reason = SM_REASON_PASSKEYT_ENTRY_FAILED; 3276 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3277 break; 3278 } 3279 3280 // wait for user action? 3281 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3282 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3283 break; 3284 } 3285 3286 // calculate and send local_confirm 3287 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3288 break; 3289 3290 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3291 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3292 sm_pdu_received_in_wrong_state(sm_conn); 3293 break;; 3294 } 3295 3296 // received random value 3297 reverse_128(&packet[1], setup->sm_peer_random); 3298 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3299 break; 3300 3301 case SM_PH3_RECEIVE_KEYS: 3302 switch(packet[0]){ 3303 case SM_CODE_ENCRYPTION_INFORMATION: 3304 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3305 reverse_128(&packet[1], setup->sm_peer_ltk); 3306 break; 3307 3308 case SM_CODE_MASTER_IDENTIFICATION: 3309 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3310 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3311 reverse_64(&packet[3], setup->sm_peer_rand); 3312 break; 3313 3314 case SM_CODE_IDENTITY_INFORMATION: 3315 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3316 reverse_128(&packet[1], setup->sm_peer_irk); 3317 break; 3318 3319 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3320 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3321 setup->sm_peer_addr_type = packet[1]; 3322 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3323 break; 3324 3325 case SM_CODE_SIGNING_INFORMATION: 3326 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3327 reverse_128(&packet[1], setup->sm_peer_csrk); 3328 break; 3329 default: 3330 // Unexpected PDU 3331 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3332 break; 3333 } 3334 // done with key distribution? 3335 if (sm_key_distribution_all_received(sm_conn)){ 3336 3337 sm_key_distribution_handle_all_received(sm_conn); 3338 3339 if (sm_conn->sm_role){ 3340 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3341 sm_done_for_handle(sm_conn->sm_handle); 3342 } else { 3343 if (setup->sm_use_secure_connections){ 3344 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3345 } else { 3346 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3347 } 3348 } 3349 } 3350 break; 3351 default: 3352 // Unexpected PDU 3353 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3354 break; 3355 } 3356 3357 // try to send preparared packet 3358 sm_run(); 3359 } 3360 3361 // Security Manager Client API 3362 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data)){ 3363 sm_get_oob_data = get_oob_data_callback; 3364 } 3365 3366 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3367 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3368 } 3369 3370 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3371 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3372 } 3373 3374 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3375 sm_min_encryption_key_size = min_size; 3376 sm_max_encryption_key_size = max_size; 3377 } 3378 3379 void sm_set_authentication_requirements(uint8_t auth_req){ 3380 sm_auth_req = auth_req; 3381 } 3382 3383 void sm_set_io_capabilities(io_capability_t io_capability){ 3384 sm_io_capabilities = io_capability; 3385 } 3386 3387 void sm_set_request_security(int enable){ 3388 sm_slave_request_security = enable; 3389 } 3390 3391 void sm_set_er(sm_key_t er){ 3392 memcpy(sm_persistent_er, er, 16); 3393 } 3394 3395 void sm_set_ir(sm_key_t ir){ 3396 memcpy(sm_persistent_ir, ir, 16); 3397 } 3398 3399 // Testing support only 3400 void sm_test_set_irk(sm_key_t irk){ 3401 memcpy(sm_persistent_irk, irk, 16); 3402 sm_persistent_irk_ready = 1; 3403 } 3404 3405 void sm_test_use_fixed_local_csrk(void){ 3406 test_use_fixed_local_csrk = 1; 3407 } 3408 3409 void sm_init(void){ 3410 // set some (BTstack default) ER and IR 3411 int i; 3412 sm_key_t er; 3413 sm_key_t ir; 3414 for (i=0;i<16;i++){ 3415 er[i] = 0x30 + i; 3416 ir[i] = 0x90 + i; 3417 } 3418 sm_set_er(er); 3419 sm_set_ir(ir); 3420 // defaults 3421 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3422 | SM_STK_GENERATION_METHOD_OOB 3423 | SM_STK_GENERATION_METHOD_PASSKEY 3424 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3425 3426 sm_max_encryption_key_size = 16; 3427 sm_min_encryption_key_size = 7; 3428 3429 sm_cmac_state = CMAC_IDLE; 3430 dkg_state = DKG_W4_WORKING; 3431 rau_state = RAU_W4_WORKING; 3432 sm_aes128_state = SM_AES128_IDLE; 3433 sm_address_resolution_test = -1; // no private address to resolve yet 3434 sm_address_resolution_ah_calculation_active = 0; 3435 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3436 sm_address_resolution_general_queue = NULL; 3437 3438 gap_random_adress_update_period = 15 * 60 * 1000L; 3439 3440 sm_active_connection = 0; 3441 3442 test_use_fixed_local_csrk = 0; 3443 3444 // register for HCI Events from HCI 3445 hci_event_callback_registration.callback = &sm_event_packet_handler; 3446 hci_add_event_handler(&hci_event_callback_registration); 3447 3448 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3449 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3450 3451 #ifdef USE_MBEDTLS_FOR_ECDH 3452 ec_key_generation_state = EC_KEY_GENERATION_IDLE; 3453 3454 #ifndef HAVE_MALLOC 3455 sm_mbedtls_allocator_init(mbedtls_memory_buffer, sizeof(mbedtls_memory_buffer)); 3456 #endif 3457 mbedtls_ecp_group_init(&mbedtls_ec_group); 3458 mbedtls_ecp_group_load(&mbedtls_ec_group, MBEDTLS_ECP_DP_SECP256R1); 3459 3460 #if 0 3461 // test 3462 sm_test_use_fixed_ec_keypair(); 3463 if (sm_have_ec_keypair){ 3464 printf("test dhkey check\n"); 3465 sm_key256_t dhkey; 3466 memcpy(setup->sm_peer_qx, ec_qx, 32); 3467 memcpy(setup->sm_peer_qy, ec_qy, 32); 3468 sm_sc_calculate_dhkey(dhkey); 3469 } 3470 #endif 3471 #endif 3472 } 3473 3474 void sm_use_fixed_ec_keypair(uint8_t * qx, uint8_t * qy, uint8_t * d){ 3475 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3476 memcpy(ec_qx, qx, 32); 3477 memcpy(ec_qy, qy, 32); 3478 memcpy(ec_d, d, 32); 3479 sm_have_ec_keypair = 1; 3480 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3481 #endif 3482 } 3483 3484 void sm_test_use_fixed_ec_keypair(void){ 3485 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3486 #ifdef USE_MBEDTLS_FOR_ECDH 3487 // use test keypair from spec 3488 mbedtls_mpi x; 3489 mbedtls_mpi_init(&x); 3490 mbedtls_mpi_read_string( &x, 16, "3f49f6d4a3c55f3874c9b3e3d2103f504aff607beb40b7995899b8a6cd3c1abd"); 3491 mbedtls_mpi_write_binary(&x, ec_d, 32); 3492 mbedtls_mpi_read_string( &x, 16, "20b003d2f297be2c5e2c83a7e9f9a5b9eff49111acf4fddbcc0301480e359de6"); 3493 mbedtls_mpi_write_binary(&x, ec_qx, 32); 3494 mbedtls_mpi_read_string( &x, 16, "dc809c49652aeb6d63329abf5a52155c766345c28fed3024741c8ed01589d28b"); 3495 mbedtls_mpi_write_binary(&x, ec_qy, 32); 3496 mbedtls_mpi_free(&x); 3497 #endif 3498 sm_have_ec_keypair = 1; 3499 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3500 #endif 3501 } 3502 3503 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3504 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3505 if (!hci_con) return NULL; 3506 return &hci_con->sm_connection; 3507 } 3508 3509 // @returns 0 if not encrypted, 7-16 otherwise 3510 int sm_encryption_key_size(hci_con_handle_t con_handle){ 3511 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3512 if (!sm_conn) return 0; // wrong connection 3513 if (!sm_conn->sm_connection_encrypted) return 0; 3514 return sm_conn->sm_actual_encryption_key_size; 3515 } 3516 3517 int sm_authenticated(hci_con_handle_t con_handle){ 3518 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3519 if (!sm_conn) return 0; // wrong connection 3520 if (!sm_conn->sm_connection_encrypted) return 0; // unencrypted connection cannot be authenticated 3521 return sm_conn->sm_connection_authenticated; 3522 } 3523 3524 authorization_state_t sm_authorization_state(hci_con_handle_t con_handle){ 3525 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3526 if (!sm_conn) return AUTHORIZATION_UNKNOWN; // wrong connection 3527 if (!sm_conn->sm_connection_encrypted) return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized 3528 if (!sm_conn->sm_connection_authenticated) return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized 3529 return sm_conn->sm_connection_authorization_state; 3530 } 3531 3532 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3533 switch (sm_conn->sm_engine_state){ 3534 case SM_GENERAL_IDLE: 3535 case SM_RESPONDER_IDLE: 3536 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3537 sm_run(); 3538 break; 3539 default: 3540 break; 3541 } 3542 } 3543 3544 /** 3545 * @brief Trigger Security Request 3546 */ 3547 void sm_send_security_request(hci_con_handle_t con_handle){ 3548 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3549 if (!sm_conn) return; 3550 sm_send_security_request_for_connection(sm_conn); 3551 } 3552 3553 // request pairing 3554 void sm_request_pairing(hci_con_handle_t con_handle){ 3555 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3556 if (!sm_conn) return; // wrong connection 3557 3558 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3559 if (sm_conn->sm_role){ 3560 sm_send_security_request_for_connection(sm_conn); 3561 } else { 3562 // used as a trigger to start central/master/initiator security procedures 3563 uint16_t ediv; 3564 sm_key_t ltk; 3565 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3566 switch (sm_conn->sm_irk_lookup_state){ 3567 case IRK_LOOKUP_FAILED: 3568 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3569 break; 3570 case IRK_LOOKUP_SUCCEEDED: 3571 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3572 if (!sm_is_null_key(ltk) || ediv){ 3573 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3574 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3575 } else { 3576 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3577 } 3578 break; 3579 default: 3580 sm_conn->sm_bonding_requested = 1; 3581 break; 3582 } 3583 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3584 sm_conn->sm_bonding_requested = 1; 3585 } 3586 } 3587 sm_run(); 3588 } 3589 3590 // called by client app on authorization request 3591 void sm_authorization_decline(hci_con_handle_t con_handle){ 3592 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3593 if (!sm_conn) return; // wrong connection 3594 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3595 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3596 } 3597 3598 void sm_authorization_grant(hci_con_handle_t con_handle){ 3599 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3600 if (!sm_conn) return; // wrong connection 3601 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3602 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3603 } 3604 3605 // GAP Bonding API 3606 3607 void sm_bonding_decline(hci_con_handle_t con_handle){ 3608 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3609 if (!sm_conn) return; // wrong connection 3610 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3611 3612 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3613 switch (setup->sm_stk_generation_method){ 3614 case PK_RESP_INPUT: 3615 case PK_INIT_INPUT: 3616 case OK_BOTH_INPUT: 3617 sm_pairing_error(sm_conn, SM_GENERAL_SEND_PAIRING_FAILED); 3618 break; 3619 case NK_BOTH_INPUT: 3620 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 3621 break; 3622 case JUST_WORKS: 3623 case OOB: 3624 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 3625 break; 3626 } 3627 } 3628 sm_run(); 3629 } 3630 3631 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3632 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3633 if (!sm_conn) return; // wrong connection 3634 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3635 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3636 if (setup->sm_use_secure_connections){ 3637 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3638 } else { 3639 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3640 } 3641 } 3642 3643 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3644 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3645 sm_sc_prepare_dhkey_check(sm_conn); 3646 } 3647 #endif 3648 3649 sm_run(); 3650 } 3651 3652 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3653 // for now, it's the same 3654 sm_just_works_confirm(con_handle); 3655 } 3656 3657 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3658 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3659 if (!sm_conn) return; // wrong connection 3660 sm_reset_tk(); 3661 big_endian_store_32(setup->sm_tk, 12, passkey); 3662 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3663 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3664 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3665 } 3666 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3667 memcpy(setup->sm_ra, setup->sm_tk, 16); 3668 memcpy(setup->sm_rb, setup->sm_tk, 16); 3669 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3670 sm_sc_start_calculating_local_confirm(sm_conn); 3671 } 3672 #endif 3673 sm_run(); 3674 } 3675 3676 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 3677 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3678 if (!sm_conn) return; // wrong connection 3679 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 3680 setup->sm_keypress_notification = action; 3681 sm_run(); 3682 } 3683 3684 /** 3685 * @brief Identify device in LE Device DB 3686 * @param handle 3687 * @returns index from le_device_db or -1 if not found/identified 3688 */ 3689 int sm_le_device_index(hci_con_handle_t con_handle ){ 3690 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3691 if (!sm_conn) return -1; 3692 return sm_conn->sm_le_db_index; 3693 } 3694 3695 // GAP LE API 3696 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 3697 gap_random_address_update_stop(); 3698 gap_random_adress_type = random_address_type; 3699 if (random_address_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3700 gap_random_address_update_start(); 3701 gap_random_address_trigger(); 3702 } 3703 3704 gap_random_address_type_t gap_random_address_get_mode(void){ 3705 return gap_random_adress_type; 3706 } 3707 3708 void gap_random_address_set_update_period(int period_ms){ 3709 gap_random_adress_update_period = period_ms; 3710 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3711 gap_random_address_update_stop(); 3712 gap_random_address_update_start(); 3713 } 3714 3715 void gap_random_address_set(bd_addr_t addr){ 3716 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_OFF); 3717 memcpy(sm_random_address, addr, 6); 3718 rau_state = RAU_SET_ADDRESS; 3719 sm_run(); 3720 } 3721 3722 /* 3723 * @brief Set Advertisement Paramters 3724 * @param adv_int_min 3725 * @param adv_int_max 3726 * @param adv_type 3727 * @param direct_address_type 3728 * @param direct_address 3729 * @param channel_map 3730 * @param filter_policy 3731 * 3732 * @note own_address_type is used from gap_random_address_set_mode 3733 */ 3734 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 3735 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 3736 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, gap_random_adress_type, 3737 direct_address_typ, direct_address, channel_map, filter_policy); 3738 } 3739 3740