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 // TODO: remove software AES 55 #include "rijndael.h" 56 #endif 57 58 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(HAVE_HCI_CONTROLLER_DHKEY_SUPPORT) 59 #define USE_MBEDTLS_FOR_ECDH 60 #endif 61 62 // Software ECDH implementation provided by mbedtls 63 #ifdef USE_MBEDTLS_FOR_ECDH 64 #if !defined(MBEDTLS_CONFIG_FILE) 65 #include "mbedtls/config.h" 66 #else 67 #include MBEDTLS_CONFIG_FILE 68 #endif 69 #if defined(MBEDTLS_PLATFORM_C) 70 #include "mbedtls/platform.h" 71 #else 72 #include <stdio.h> 73 #define mbedtls_printf printf 74 #endif 75 #include "mbedtls/ecp.h" 76 #endif 77 78 // 79 // SM internal types and globals 80 // 81 82 typedef enum { 83 DKG_W4_WORKING, 84 DKG_CALC_IRK, 85 DKG_W4_IRK, 86 DKG_CALC_DHK, 87 DKG_W4_DHK, 88 DKG_READY 89 } derived_key_generation_t; 90 91 typedef enum { 92 RAU_W4_WORKING, 93 RAU_IDLE, 94 RAU_GET_RANDOM, 95 RAU_W4_RANDOM, 96 RAU_GET_ENC, 97 RAU_W4_ENC, 98 RAU_SET_ADDRESS, 99 } random_address_update_t; 100 101 typedef enum { 102 CMAC_IDLE, 103 CMAC_CALC_SUBKEYS, 104 CMAC_W4_SUBKEYS, 105 CMAC_CALC_MI, 106 CMAC_W4_MI, 107 CMAC_CALC_MLAST, 108 CMAC_W4_MLAST 109 } cmac_state_t; 110 111 typedef enum { 112 JUST_WORKS, 113 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 114 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 115 OK_BOTH_INPUT, // Only input on both, both input PK 116 NK_BOTH_INPUT, // Only numerical compparison (yes/no) on on both sides 117 OOB // OOB available on both sides 118 } stk_generation_method_t; 119 120 typedef enum { 121 SM_USER_RESPONSE_IDLE, 122 SM_USER_RESPONSE_PENDING, 123 SM_USER_RESPONSE_CONFIRM, 124 SM_USER_RESPONSE_PASSKEY, 125 SM_USER_RESPONSE_DECLINE 126 } sm_user_response_t; 127 128 typedef enum { 129 SM_AES128_IDLE, 130 SM_AES128_ACTIVE 131 } sm_aes128_state_t; 132 133 typedef enum { 134 ADDRESS_RESOLUTION_IDLE, 135 ADDRESS_RESOLUTION_GENERAL, 136 ADDRESS_RESOLUTION_FOR_CONNECTION, 137 } address_resolution_mode_t; 138 139 typedef enum { 140 ADDRESS_RESOLUTION_SUCEEDED, 141 ADDRESS_RESOLUTION_FAILED, 142 } address_resolution_event_t; 143 // 144 // GLOBAL DATA 145 // 146 147 static uint8_t test_use_fixed_local_csrk; 148 149 // configuration 150 static uint8_t sm_accepted_stk_generation_methods; 151 static uint8_t sm_max_encryption_key_size; 152 static uint8_t sm_min_encryption_key_size; 153 static uint8_t sm_auth_req = 0; 154 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 155 static uint8_t sm_slave_request_security; 156 157 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 158 static sm_key_t sm_persistent_er; 159 static sm_key_t sm_persistent_ir; 160 161 // derived from sm_persistent_ir 162 static sm_key_t sm_persistent_dhk; 163 static sm_key_t sm_persistent_irk; 164 static uint8_t sm_persistent_irk_ready = 0; // used for testing 165 static derived_key_generation_t dkg_state; 166 167 // derived from sm_persistent_er 168 // .. 169 170 // random address update 171 static random_address_update_t rau_state; 172 static bd_addr_t sm_random_address; 173 174 // CMAC calculation 175 static cmac_state_t sm_cmac_state; 176 static sm_key_t sm_cmac_k; 177 static uint8_t sm_cmac_header[3]; 178 static uint16_t sm_cmac_message_len; 179 static uint8_t * sm_cmac_message; 180 static uint8_t sm_cmac_sign_counter[4]; 181 static sm_key_t sm_cmac_m_last; 182 static sm_key_t sm_cmac_x; 183 static uint8_t sm_cmac_block_current; 184 static uint8_t sm_cmac_block_count; 185 static void (*sm_cmac_done_handler)(uint8_t hash[8]); 186 187 // resolvable private address lookup / CSRK calculation 188 static int sm_address_resolution_test; 189 static int sm_address_resolution_ah_calculation_active; 190 static uint8_t sm_address_resolution_addr_type; 191 static bd_addr_t sm_address_resolution_address; 192 static void * sm_address_resolution_context; 193 static address_resolution_mode_t sm_address_resolution_mode; 194 static btstack_linked_list_t sm_address_resolution_general_queue; 195 196 // aes128 crypto engine. store current sm_connection_t in sm_aes128_context 197 static sm_aes128_state_t sm_aes128_state; 198 static void * sm_aes128_context; 199 200 // random engine. store context (ususally sm_connection_t) 201 static void * sm_random_context; 202 203 // to receive hci events 204 static btstack_packet_callback_registration_t hci_event_callback_registration; 205 206 /* to dispatch sm event */ 207 static btstack_linked_list_t sm_event_handlers; 208 209 // Software ECDH implementation provided by mbedtls 210 #ifdef USE_MBEDTLS_FOR_ECDH 211 mbedtls_ecp_keypair le_keypair; 212 #endif 213 214 // 215 // Volume 3, Part H, Chapter 24 216 // "Security shall be initiated by the Security Manager in the device in the master role. 217 // The device in the slave role shall be the responding device." 218 // -> master := initiator, slave := responder 219 // 220 221 // data needed for security setup 222 typedef struct sm_setup_context { 223 224 btstack_timer_source_t sm_timeout; 225 226 // used in all phases 227 uint8_t sm_pairing_failed_reason; 228 229 // user response, (Phase 1 and/or 2) 230 uint8_t sm_user_response; 231 232 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 233 int sm_key_distribution_send_set; 234 int sm_key_distribution_received_set; 235 236 // Phase 2 (Pairing over SMP) 237 stk_generation_method_t sm_stk_generation_method; 238 sm_key_t sm_tk; 239 uint8_t sm_use_secure_connections; 240 241 sm_key_t sm_c1_t3_value; // c1 calculation 242 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 243 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 244 sm_key_t sm_local_random; 245 sm_key_t sm_local_confirm; 246 sm_key_t sm_peer_random; 247 sm_key_t sm_peer_confirm; 248 uint8_t sm_m_addr_type; // address and type can be removed 249 uint8_t sm_s_addr_type; // '' 250 bd_addr_t sm_m_address; // '' 251 bd_addr_t sm_s_address; // '' 252 sm_key_t sm_ltk; 253 254 #ifdef ENABLE_LE_SECURE_CONNECTIONS 255 uint8_t sm_peer_qx[32]; 256 uint8_t sm_peer_qy[32]; 257 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 258 sm_key_t sm_local_nonce; // might be combined with sm_local_random 259 sm_key_t sm_peer_dhkey_check; 260 sm_key_t sm_local_dhkey_check; 261 sm_key_t sm_ra; 262 sm_key_t sm_rb; 263 uint8_t sm_passkey_bit; 264 #endif 265 266 // Phase 3 267 268 // key distribution, we generate 269 uint16_t sm_local_y; 270 uint16_t sm_local_div; 271 uint16_t sm_local_ediv; 272 uint8_t sm_local_rand[8]; 273 sm_key_t sm_local_ltk; 274 sm_key_t sm_local_csrk; 275 sm_key_t sm_local_irk; 276 // sm_local_address/addr_type not needed 277 278 // key distribution, received from peer 279 uint16_t sm_peer_y; 280 uint16_t sm_peer_div; 281 uint16_t sm_peer_ediv; 282 uint8_t sm_peer_rand[8]; 283 sm_key_t sm_peer_ltk; 284 sm_key_t sm_peer_irk; 285 sm_key_t sm_peer_csrk; 286 uint8_t sm_peer_addr_type; 287 bd_addr_t sm_peer_address; 288 289 } sm_setup_context_t; 290 291 // 292 static sm_setup_context_t the_setup; 293 static sm_setup_context_t * setup = &the_setup; 294 295 // active connection - the one for which the_setup is used for 296 static uint16_t sm_active_connection = 0; 297 298 // @returns 1 if oob data is available 299 // stores oob data in provided 16 byte buffer if not null 300 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 301 302 // used to notify applicationss that user interaction is neccessary, see sm_notify_t below 303 static btstack_packet_handler_t sm_client_packet_handler = NULL; 304 305 // horizontal: initiator capabilities 306 // vertial: responder capabilities 307 static const stk_generation_method_t stk_generation_method [5] [5] = { 308 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 309 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 310 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 311 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 312 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 313 }; 314 315 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 316 #ifdef ENABLE_LE_SECURE_CONNECTIONS 317 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 318 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 319 { JUST_WORKS, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 320 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 321 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 322 { PK_RESP_INPUT, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 323 }; 324 #endif 325 326 static void sm_run(void); 327 static void sm_done_for_handle(hci_con_handle_t con_handle); 328 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 329 static inline int sm_calc_actual_encryption_key_size(int other); 330 static int sm_validate_stk_generation_method(void); 331 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data); 332 333 static void log_info_hex16(const char * name, uint16_t value){ 334 log_info("%-6s 0x%04x", name, value); 335 } 336 337 // @returns 1 if all bytes are 0 338 static int sm_is_null_random(uint8_t random[8]){ 339 int i; 340 for (i=0; i < 8 ; i++){ 341 if (random[i]) return 0; 342 } 343 return 1; 344 } 345 346 // Key utils 347 static void sm_reset_tk(void){ 348 int i; 349 for (i=0;i<16;i++){ 350 setup->sm_tk[i] = 0; 351 } 352 } 353 354 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 355 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 356 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 357 int i; 358 for (i = max_encryption_size ; i < 16 ; i++){ 359 key[15-i] = 0; 360 } 361 } 362 363 // SMP Timeout implementation 364 365 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 366 // the Security Manager Timer shall be reset and started. 367 // 368 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 369 // 370 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 371 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 372 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 373 // established. 374 375 static void sm_timeout_handler(btstack_timer_source_t * timer){ 376 log_info("SM timeout"); 377 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 378 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 379 sm_done_for_handle(sm_conn->sm_handle); 380 381 // trigger handling of next ready connection 382 sm_run(); 383 } 384 static void sm_timeout_start(sm_connection_t * sm_conn){ 385 btstack_run_loop_remove_timer(&setup->sm_timeout); 386 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 387 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 388 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 389 btstack_run_loop_add_timer(&setup->sm_timeout); 390 } 391 static void sm_timeout_stop(void){ 392 btstack_run_loop_remove_timer(&setup->sm_timeout); 393 } 394 static void sm_timeout_reset(sm_connection_t * sm_conn){ 395 sm_timeout_stop(); 396 sm_timeout_start(sm_conn); 397 } 398 399 // end of sm timeout 400 401 // GAP Random Address updates 402 static gap_random_address_type_t gap_random_adress_type; 403 static btstack_timer_source_t gap_random_address_update_timer; 404 static uint32_t gap_random_adress_update_period; 405 406 static void gap_random_address_trigger(void){ 407 if (rau_state != RAU_IDLE) return; 408 log_info("gap_random_address_trigger"); 409 rau_state = RAU_GET_RANDOM; 410 sm_run(); 411 } 412 413 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 414 log_info("GAP Random Address Update due"); 415 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 416 btstack_run_loop_add_timer(&gap_random_address_update_timer); 417 gap_random_address_trigger(); 418 } 419 420 static void gap_random_address_update_start(void){ 421 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 422 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 423 btstack_run_loop_add_timer(&gap_random_address_update_timer); 424 } 425 426 static void gap_random_address_update_stop(void){ 427 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 428 } 429 430 431 static void sm_random_start(void * context){ 432 sm_random_context = context; 433 hci_send_cmd(&hci_le_rand); 434 } 435 436 // pre: sm_aes128_state != SM_AES128_ACTIVE, hci_can_send_command == 1 437 // context is made availabe to aes128 result handler by this 438 static void sm_aes128_start(sm_key_t key, sm_key_t plaintext, void * context){ 439 sm_aes128_state = SM_AES128_ACTIVE; 440 sm_key_t key_flipped, plaintext_flipped; 441 reverse_128(key, key_flipped); 442 reverse_128(plaintext, plaintext_flipped); 443 sm_aes128_context = context; 444 hci_send_cmd(&hci_le_encrypt, key_flipped, plaintext_flipped); 445 } 446 447 // ah(k,r) helper 448 // r = padding || r 449 // r - 24 bit value 450 static void sm_ah_r_prime(uint8_t r[3], sm_key_t r_prime){ 451 // r'= padding || r 452 memset(r_prime, 0, 16); 453 memcpy(&r_prime[13], r, 3); 454 } 455 456 // d1 helper 457 // d' = padding || r || d 458 // d,r - 16 bit values 459 static void sm_d1_d_prime(uint16_t d, uint16_t r, sm_key_t d1_prime){ 460 // d'= padding || r || d 461 memset(d1_prime, 0, 16); 462 big_endian_store_16(d1_prime, 12, r); 463 big_endian_store_16(d1_prime, 14, d); 464 } 465 466 // dm helper 467 // r’ = padding || r 468 // r - 64 bit value 469 static void sm_dm_r_prime(uint8_t r[8], sm_key_t r_prime){ 470 memset(r_prime, 0, 16); 471 memcpy(&r_prime[8], r, 8); 472 } 473 474 // calculate arguments for first AES128 operation in C1 function 475 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){ 476 477 // p1 = pres || preq || rat’ || iat’ 478 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 479 // cant octet of pres becomes the most significant octet of p1. 480 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 481 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 482 // p1 is 0x05000800000302070710000001010001." 483 484 sm_key_t p1; 485 reverse_56(pres, &p1[0]); 486 reverse_56(preq, &p1[7]); 487 p1[14] = rat; 488 p1[15] = iat; 489 log_info_key("p1", p1); 490 log_info_key("r", r); 491 492 // t1 = r xor p1 493 int i; 494 for (i=0;i<16;i++){ 495 t1[i] = r[i] ^ p1[i]; 496 } 497 log_info_key("t1", t1); 498 } 499 500 // calculate arguments for second AES128 operation in C1 function 501 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, sm_key_t t3){ 502 // p2 = padding || ia || ra 503 // "The least significant octet of ra becomes the least significant octet of p2 and 504 // the most significant octet of padding becomes the most significant octet of p2. 505 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 506 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 507 508 sm_key_t p2; 509 memset(p2, 0, 16); 510 memcpy(&p2[4], ia, 6); 511 memcpy(&p2[10], ra, 6); 512 log_info_key("p2", p2); 513 514 // c1 = e(k, t2_xor_p2) 515 int i; 516 for (i=0;i<16;i++){ 517 t3[i] = t2[i] ^ p2[i]; 518 } 519 log_info_key("t3", t3); 520 } 521 522 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, sm_key_t r_prime){ 523 log_info_key("r1", r1); 524 log_info_key("r2", r2); 525 memcpy(&r_prime[8], &r2[8], 8); 526 memcpy(&r_prime[0], &r1[8], 8); 527 } 528 529 #ifdef ENABLE_LE_SECURE_CONNECTIONS 530 // Software implementations of crypto toolbox for LE Secure Connection 531 // TODO: replace with code to use AES Engine of HCI Controller 532 typedef uint8_t sm_key24_t[3]; 533 typedef uint8_t sm_key56_t[7]; 534 typedef uint8_t sm_key256_t[32]; 535 536 static void aes128_calc_cyphertext(const uint8_t key[16], const uint8_t plaintext[16], uint8_t cyphertext[16]){ 537 uint32_t rk[RKLENGTH(KEYBITS)]; 538 int nrounds = rijndaelSetupEncrypt(rk, &key[0], KEYBITS); 539 rijndaelEncrypt(rk, nrounds, plaintext, cyphertext); 540 } 541 542 static void calc_subkeys(sm_key_t k0, sm_key_t k1, sm_key_t k2){ 543 memcpy(k1, k0, 16); 544 sm_shift_left_by_one_bit_inplace(16, k1); 545 if (k0[0] & 0x80){ 546 k1[15] ^= 0x87; 547 } 548 memcpy(k2, k1, 16); 549 sm_shift_left_by_one_bit_inplace(16, k2); 550 if (k1[0] & 0x80){ 551 k2[15] ^= 0x87; 552 } 553 } 554 555 static void aes_cmac(sm_key_t aes_cmac, const sm_key_t key, const uint8_t * data, int cmac_message_len){ 556 sm_key_t k0, k1, k2, zero; 557 memset(zero, 0, 16); 558 559 aes128_calc_cyphertext(key, zero, k0); 560 calc_subkeys(k0, k1, k2); 561 562 int cmac_block_count = (cmac_message_len + 15) / 16; 563 564 // step 3: .. 565 if (cmac_block_count==0){ 566 cmac_block_count = 1; 567 } 568 569 // step 4: set m_last 570 sm_key_t cmac_m_last; 571 int sm_cmac_last_block_complete = cmac_message_len != 0 && (cmac_message_len & 0x0f) == 0; 572 int i; 573 if (sm_cmac_last_block_complete){ 574 for (i=0;i<16;i++){ 575 cmac_m_last[i] = data[cmac_message_len - 16 + i] ^ k1[i]; 576 } 577 } else { 578 int valid_octets_in_last_block = cmac_message_len & 0x0f; 579 for (i=0;i<16;i++){ 580 if (i < valid_octets_in_last_block){ 581 cmac_m_last[i] = data[(cmac_message_len & 0xfff0) + i] ^ k2[i]; 582 continue; 583 } 584 if (i == valid_octets_in_last_block){ 585 cmac_m_last[i] = 0x80 ^ k2[i]; 586 continue; 587 } 588 cmac_m_last[i] = k2[i]; 589 } 590 } 591 592 // printf("sm_cmac_start: len %u, block count %u\n", cmac_message_len, cmac_block_count); 593 // LOG_KEY(cmac_m_last); 594 595 // Step 5 596 sm_key_t cmac_x; 597 memset(cmac_x, 0, 16); 598 599 // Step 6 600 sm_key_t sm_cmac_y; 601 for (int block = 0 ; block < cmac_block_count-1 ; block++){ 602 for (i=0;i<16;i++){ 603 sm_cmac_y[i] = cmac_x[i] ^ data[block * 16 + i]; 604 } 605 aes128_calc_cyphertext(key, sm_cmac_y, cmac_x); 606 } 607 for (i=0;i<16;i++){ 608 sm_cmac_y[i] = cmac_x[i] ^ cmac_m_last[i]; 609 } 610 611 // Step 7 612 aes128_calc_cyphertext(key, sm_cmac_y, aes_cmac); 613 } 614 615 static void f4(sm_key_t res, const sm_key256_t u, const sm_key256_t v, const sm_key_t x, uint8_t z){ 616 uint8_t buffer[65]; 617 memcpy(buffer, u, 32); 618 memcpy(buffer+32, v, 32); 619 buffer[64] = z; 620 log_info("f4 key"); 621 log_info_hexdump(x, 16); 622 log_info("f4 message"); 623 log_info_hexdump(buffer, sizeof(buffer)); 624 aes_cmac(res, x, buffer, sizeof(buffer)); 625 } 626 627 const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 628 const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 629 const uint8_t f5_length[] = { 0x01, 0x00}; 630 static void f5(sm_key256_t res, const sm_key256_t w, const sm_key_t n1, const sm_key_t n2, const sm_key56_t a1, const sm_key56_t a2){ 631 // T = AES-CMACSAL_T(W) 632 sm_key_t t; 633 aes_cmac(t, f5_salt, w, 32); 634 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 635 uint8_t buffer[53]; 636 buffer[0] = 0; 637 memcpy(buffer+01, f5_key_id, 4); 638 memcpy(buffer+05, n1, 16); 639 memcpy(buffer+21, n2, 16); 640 memcpy(buffer+37, a1, 7); 641 memcpy(buffer+44, a2, 7); 642 memcpy(buffer+51, f5_length, 2); 643 log_info("f5 DHKEY"); 644 log_info_hexdump(w, 32); 645 log_info("f5 key"); 646 log_info_hexdump(t, 16); 647 log_info("f5 message for MacKey"); 648 log_info_hexdump(buffer, sizeof(buffer)); 649 aes_cmac(res, t, buffer, sizeof(buffer)); 650 // hexdump2(res, 16); 651 // || AES-CMACT (Counter = 1 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the LTK 652 buffer[0] = 1; 653 // hexdump2(buffer, sizeof(buffer)); 654 log_info("f5 message for LTK"); 655 log_info_hexdump(buffer, sizeof(buffer)); 656 aes_cmac(res+16, t, buffer, sizeof(buffer)); 657 // hexdump2(res+16, 16); 658 } 659 660 // f6(W, N1, N2, R, IOcap, A1, A2) = AES-CMACW (N1 || N2 || R || IOcap || A1 || A2 661 // - W is 128 bits 662 // - N1 is 128 bits 663 // - N2 is 128 bits 664 // - R is 128 bits 665 // - IOcap is 24 bits 666 // - A1 is 56 bits 667 // - A2 is 56 bits 668 static void f6(sm_key_t res, 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){ 669 uint8_t buffer[65]; 670 memcpy(buffer, n1, 16); 671 memcpy(buffer+16, n2, 16); 672 memcpy(buffer+32, r, 16); 673 memcpy(buffer+48, io_cap, 3); 674 memcpy(buffer+51, a1, 7); 675 memcpy(buffer+58, a2, 7); 676 log_info("f6 key"); 677 log_info_hexdump(w, 16); 678 log_info("f6 message"); 679 log_info_hexdump(buffer, sizeof(buffer)); 680 aes_cmac(res, w, buffer,sizeof(buffer)); 681 } 682 683 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 684 // - U is 256 bits 685 // - V is 256 bits 686 // - X is 128 bits 687 // - Y is 128 bits 688 static uint32_t g2(const sm_key256_t u, const sm_key256_t v, const sm_key_t x, const sm_key_t y){ 689 uint8_t buffer[80]; 690 memcpy(buffer, u, 32); 691 memcpy(buffer+32, v, 32); 692 memcpy(buffer+64, y, 16); 693 sm_key_t cmac; 694 log_info("g2 key"); 695 log_info_hexdump(x, 16); 696 log_info("g2 message"); 697 log_info_hexdump(buffer, sizeof(buffer)); 698 aes_cmac(cmac, x, buffer, sizeof(buffer)); 699 log_info("g2 result"); 700 log_info_hexdump(x, 16); 701 return big_endian_read_32(cmac, 12); 702 } 703 704 #if 0 705 // h6(W, keyID) = AES-CMACW(keyID) 706 // - W is 128 bits 707 // - keyID is 32 bits 708 static void h6(sm_key_t res, const sm_key_t w, const uint32_t key_id){ 709 uint8_t key_id_buffer[4]; 710 big_endian_store_32(key_id_buffer, 0, key_id); 711 aes_cmac(res, w, key_id_buffer, 4); 712 } 713 #endif 714 #endif 715 716 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){ 717 event[0] = type; 718 event[1] = event_size - 2; 719 little_endian_store_16(event, 2, con_handle); 720 event[4] = addr_type; 721 reverse_bd_addr(address, &event[5]); 722 } 723 724 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 725 if (sm_client_packet_handler) { 726 sm_client_packet_handler(HCI_EVENT_PACKET, 0, packet, size); 727 } 728 // dispatch to all event handlers 729 btstack_linked_list_iterator_t it; 730 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 731 while (btstack_linked_list_iterator_has_next(&it)){ 732 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 733 entry->callback(packet_type, 0, packet, size); 734 } 735 } 736 737 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 738 uint8_t event[11]; 739 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 740 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 741 } 742 743 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){ 744 uint8_t event[15]; 745 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 746 little_endian_store_32(event, 11, passkey); 747 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 748 } 749 750 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){ 751 uint8_t event[13]; 752 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 753 little_endian_store_16(event, 11, index); 754 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 755 } 756 757 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){ 758 759 uint8_t event[18]; 760 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 761 event[11] = result; 762 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 763 } 764 765 // decide on stk generation based on 766 // - pairing request 767 // - io capabilities 768 // - OOB data availability 769 static void sm_setup_tk(void){ 770 771 // default: just works 772 setup->sm_stk_generation_method = JUST_WORKS; 773 774 #ifdef ENABLE_LE_SECURE_CONNECTIONS 775 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 776 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 777 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 778 memset(setup->sm_ra, 0, 16); 779 memset(setup->sm_rb, 0, 16); 780 #else 781 setup->sm_use_secure_connections = 0; 782 #endif 783 784 // If both devices have not set the MITM option in the Authentication Requirements 785 // Flags, then the IO capabilities shall be ignored and the Just Works association 786 // model shall be used. 787 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 788 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 789 log_info("SM: MITM not required by both -> JUST WORKS"); 790 return; 791 } 792 793 // TODO: with LE SC, OOB is used to transfer data OOB during pairing, single device with OOB is sufficient 794 795 // If both devices have out of band authentication data, then the Authentication 796 // Requirements Flags shall be ignored when selecting the pairing method and the 797 // Out of Band pairing method shall be used. 798 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) 799 && sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)){ 800 log_info("SM: have OOB data"); 801 log_info_key("OOB", setup->sm_tk); 802 setup->sm_stk_generation_method = OOB; 803 return; 804 } 805 806 // Reset TK as it has been setup in sm_init_setup 807 sm_reset_tk(); 808 809 // Also use just works if unknown io capabilites 810 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)){ 811 return; 812 } 813 814 // Otherwise the IO capabilities of the devices shall be used to determine the 815 // pairing method as defined in Table 2.4. 816 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 817 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 818 819 #ifdef ENABLE_LE_SECURE_CONNECTIONS 820 if (setup->sm_use_secure_connections){ 821 generation_method = stk_generation_method_with_secure_connection; 822 } 823 #endif 824 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)]; 825 826 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 827 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); 828 } 829 830 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 831 int flags = 0; 832 if (key_set & SM_KEYDIST_ENC_KEY){ 833 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 834 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 835 } 836 if (key_set & SM_KEYDIST_ID_KEY){ 837 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 838 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 839 } 840 if (key_set & SM_KEYDIST_SIGN){ 841 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 842 } 843 return flags; 844 } 845 846 static void sm_setup_key_distribution(uint8_t key_set){ 847 setup->sm_key_distribution_received_set = 0; 848 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 849 } 850 851 // CSRK Key Lookup 852 853 854 static int sm_address_resolution_idle(void){ 855 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 856 } 857 858 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){ 859 memcpy(sm_address_resolution_address, addr, 6); 860 sm_address_resolution_addr_type = addr_type; 861 sm_address_resolution_test = 0; 862 sm_address_resolution_mode = mode; 863 sm_address_resolution_context = context; 864 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 865 } 866 867 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 868 // check if already in list 869 btstack_linked_list_iterator_t it; 870 sm_lookup_entry_t * entry; 871 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 872 while(btstack_linked_list_iterator_has_next(&it)){ 873 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 874 if (entry->address_type != address_type) continue; 875 if (memcmp(entry->address, address, 6)) continue; 876 // already in list 877 return BTSTACK_BUSY; 878 } 879 entry = btstack_memory_sm_lookup_entry_get(); 880 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 881 entry->address_type = (bd_addr_type_t) address_type; 882 memcpy(entry->address, address, 6); 883 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 884 sm_run(); 885 return 0; 886 } 887 888 // CMAC Implementation using AES128 engine 889 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 890 int i; 891 int carry = 0; 892 for (i=len-1; i >= 0 ; i--){ 893 int new_carry = data[i] >> 7; 894 data[i] = data[i] << 1 | carry; 895 carry = new_carry; 896 } 897 } 898 899 // 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 900 static inline void sm_next_responding_state(sm_connection_t * sm_conn){ 901 sm_conn->sm_engine_state = (security_manager_state_t) (((int)sm_conn->sm_engine_state) + 1); 902 } 903 static inline void dkg_next_state(void){ 904 dkg_state = (derived_key_generation_t) (((int)dkg_state) + 1); 905 } 906 static inline void rau_next_state(void){ 907 rau_state = (random_address_update_t) (((int)rau_state) + 1); 908 } 909 static inline void sm_cmac_next_state(void){ 910 sm_cmac_state = (cmac_state_t) (((int)sm_cmac_state) + 1); 911 } 912 static int sm_cmac_last_block_complete(void){ 913 if (sm_cmac_message_len == 0) return 0; 914 return (sm_cmac_message_len & 0x0f) == 0; 915 } 916 static inline uint8_t sm_cmac_message_get_byte(int offset){ 917 if (offset >= sm_cmac_message_len) { 918 log_error("sm_cmac_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_message_len); 919 return 0; 920 } 921 922 offset = sm_cmac_message_len - 1 - offset; 923 924 // sm_cmac_header[3] | message[] | sm_cmac_sign_counter[4] 925 if (offset < 3){ 926 return sm_cmac_header[offset]; 927 } 928 int actual_message_len_incl_header = sm_cmac_message_len - 4; 929 if (offset < actual_message_len_incl_header){ 930 return sm_cmac_message[offset - 3]; 931 } 932 return sm_cmac_sign_counter[offset - actual_message_len_incl_header]; 933 } 934 935 void sm_cmac_start(sm_key_t k, uint8_t opcode, hci_con_handle_t con_handle, uint16_t message_len, uint8_t * message, uint32_t sign_counter, void (*done_handler)(uint8_t hash[8])){ 936 memcpy(sm_cmac_k, k, 16); 937 sm_cmac_header[0] = opcode; 938 little_endian_store_16(sm_cmac_header, 1, con_handle); 939 little_endian_store_32(sm_cmac_sign_counter, 0, sign_counter); 940 sm_cmac_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 941 sm_cmac_message = message; 942 sm_cmac_done_handler = done_handler; 943 sm_cmac_block_current = 0; 944 memset(sm_cmac_x, 0, 16); 945 946 // step 2: n := ceil(len/const_Bsize); 947 sm_cmac_block_count = (sm_cmac_message_len + 15) / 16; 948 949 // step 3: .. 950 if (sm_cmac_block_count==0){ 951 sm_cmac_block_count = 1; 952 } 953 954 log_info("sm_cmac_start: len %u, block count %u", sm_cmac_message_len, sm_cmac_block_count); 955 956 // first, we need to compute l for k1, k2, and m_last 957 sm_cmac_state = CMAC_CALC_SUBKEYS; 958 959 // let's go 960 sm_run(); 961 } 962 963 int sm_cmac_ready(void){ 964 return sm_cmac_state == CMAC_IDLE; 965 } 966 967 static void sm_cmac_handle_aes_engine_ready(void){ 968 switch (sm_cmac_state){ 969 case CMAC_CALC_SUBKEYS: { 970 sm_key_t const_zero; 971 memset(const_zero, 0, 16); 972 sm_cmac_next_state(); 973 sm_aes128_start(sm_cmac_k, const_zero, NULL); 974 break; 975 } 976 case CMAC_CALC_MI: { 977 int j; 978 sm_key_t y; 979 for (j=0;j<16;j++){ 980 y[j] = sm_cmac_x[j] ^ sm_cmac_message_get_byte(sm_cmac_block_current*16 + j); 981 } 982 sm_cmac_block_current++; 983 sm_cmac_next_state(); 984 sm_aes128_start(sm_cmac_k, y, NULL); 985 break; 986 } 987 case CMAC_CALC_MLAST: { 988 int i; 989 sm_key_t y; 990 for (i=0;i<16;i++){ 991 y[i] = sm_cmac_x[i] ^ sm_cmac_m_last[i]; 992 } 993 log_info_key("Y", y); 994 sm_cmac_block_current++; 995 sm_cmac_next_state(); 996 sm_aes128_start(sm_cmac_k, y, NULL); 997 break; 998 } 999 default: 1000 log_info("sm_cmac_handle_aes_engine_ready called in state %u", sm_cmac_state); 1001 break; 1002 } 1003 } 1004 1005 static void sm_cmac_handle_encryption_result(sm_key_t data){ 1006 switch (sm_cmac_state){ 1007 case CMAC_W4_SUBKEYS: { 1008 sm_key_t k1; 1009 memcpy(k1, data, 16); 1010 sm_shift_left_by_one_bit_inplace(16, k1); 1011 if (data[0] & 0x80){ 1012 k1[15] ^= 0x87; 1013 } 1014 sm_key_t k2; 1015 memcpy(k2, k1, 16); 1016 sm_shift_left_by_one_bit_inplace(16, k2); 1017 if (k1[0] & 0x80){ 1018 k2[15] ^= 0x87; 1019 } 1020 1021 log_info_key("k", sm_cmac_k); 1022 log_info_key("k1", k1); 1023 log_info_key("k2", k2); 1024 1025 // step 4: set m_last 1026 int i; 1027 if (sm_cmac_last_block_complete()){ 1028 for (i=0;i<16;i++){ 1029 sm_cmac_m_last[i] = sm_cmac_message_get_byte(sm_cmac_message_len - 16 + i) ^ k1[i]; 1030 } 1031 } else { 1032 int valid_octets_in_last_block = sm_cmac_message_len & 0x0f; 1033 for (i=0;i<16;i++){ 1034 if (i < valid_octets_in_last_block){ 1035 sm_cmac_m_last[i] = sm_cmac_message_get_byte((sm_cmac_message_len & 0xfff0) + i) ^ k2[i]; 1036 continue; 1037 } 1038 if (i == valid_octets_in_last_block){ 1039 sm_cmac_m_last[i] = 0x80 ^ k2[i]; 1040 continue; 1041 } 1042 sm_cmac_m_last[i] = k2[i]; 1043 } 1044 } 1045 1046 // next 1047 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1048 break; 1049 } 1050 case CMAC_W4_MI: 1051 memcpy(sm_cmac_x, data, 16); 1052 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1053 break; 1054 case CMAC_W4_MLAST: 1055 // done 1056 log_info_key("CMAC", data); 1057 sm_cmac_done_handler(data); 1058 sm_cmac_state = CMAC_IDLE; 1059 break; 1060 default: 1061 log_info("sm_cmac_handle_encryption_result called in state %u", sm_cmac_state); 1062 break; 1063 } 1064 } 1065 1066 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 1067 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 1068 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 1069 switch (setup->sm_stk_generation_method){ 1070 case PK_RESP_INPUT: 1071 if (sm_conn->sm_role){ 1072 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1073 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1074 } else { 1075 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)); 1076 } 1077 break; 1078 case PK_INIT_INPUT: 1079 if (sm_conn->sm_role){ 1080 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)); 1081 } else { 1082 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1083 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1084 } 1085 break; 1086 case OK_BOTH_INPUT: 1087 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1088 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1089 break; 1090 case NK_BOTH_INPUT: 1091 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1092 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)); 1093 break; 1094 case JUST_WORKS: 1095 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1096 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1097 break; 1098 case OOB: 1099 // client already provided OOB data, let's skip notification. 1100 break; 1101 } 1102 } 1103 1104 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 1105 int recv_flags; 1106 if (sm_conn->sm_role){ 1107 // slave / responder 1108 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 1109 } else { 1110 // master / initiator 1111 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 1112 } 1113 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1114 return recv_flags == setup->sm_key_distribution_received_set; 1115 } 1116 1117 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1118 if (sm_active_connection == con_handle){ 1119 sm_timeout_stop(); 1120 sm_active_connection = 0; 1121 log_info("sm: connection 0x%x released setup context", con_handle); 1122 } 1123 } 1124 1125 static int sm_key_distribution_flags_for_auth_req(void){ 1126 int flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_SIGN; 1127 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1128 // encryption information only if bonding requested 1129 flags |= SM_KEYDIST_ENC_KEY; 1130 } 1131 return flags; 1132 } 1133 1134 static void sm_init_setup(sm_connection_t * sm_conn){ 1135 1136 // fill in sm setup 1137 sm_reset_tk(); 1138 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1139 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1140 1141 // query client for OOB data 1142 int have_oob_data = 0; 1143 if (sm_get_oob_data) { 1144 have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1145 } 1146 1147 sm_pairing_packet_t * local_packet; 1148 if (sm_conn->sm_role){ 1149 // slave 1150 local_packet = &setup->sm_s_pres; 1151 gap_advertisements_get_address(&setup->sm_s_addr_type, setup->sm_s_address); 1152 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1153 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1154 } else { 1155 // master 1156 local_packet = &setup->sm_m_preq; 1157 gap_advertisements_get_address(&setup->sm_m_addr_type, setup->sm_m_address); 1158 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1159 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1160 1161 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1162 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1163 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1164 } 1165 1166 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1167 sm_pairing_packet_set_oob_data_flag(*local_packet, have_oob_data); 1168 sm_pairing_packet_set_auth_req(*local_packet, sm_auth_req); 1169 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1170 } 1171 1172 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1173 1174 sm_pairing_packet_t * remote_packet; 1175 int remote_key_request; 1176 if (sm_conn->sm_role){ 1177 // slave / responder 1178 remote_packet = &setup->sm_m_preq; 1179 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1180 } else { 1181 // master / initiator 1182 remote_packet = &setup->sm_s_pres; 1183 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1184 } 1185 1186 // check key size 1187 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1188 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1189 1190 // decide on STK generation method 1191 sm_setup_tk(); 1192 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1193 1194 // check if STK generation method is acceptable by client 1195 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1196 1197 // identical to responder 1198 sm_setup_key_distribution(remote_key_request); 1199 1200 // JUST WORKS doens't provide authentication 1201 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1202 1203 return 0; 1204 } 1205 1206 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1207 1208 // cache and reset context 1209 int matched_device_id = sm_address_resolution_test; 1210 address_resolution_mode_t mode = sm_address_resolution_mode; 1211 void * context = sm_address_resolution_context; 1212 1213 // reset context 1214 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1215 sm_address_resolution_context = NULL; 1216 sm_address_resolution_test = -1; 1217 hci_con_handle_t con_handle = 0; 1218 1219 sm_connection_t * sm_connection; 1220 uint16_t ediv; 1221 switch (mode){ 1222 case ADDRESS_RESOLUTION_GENERAL: 1223 break; 1224 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1225 sm_connection = (sm_connection_t *) context; 1226 con_handle = sm_connection->sm_handle; 1227 switch (event){ 1228 case ADDRESS_RESOLUTION_SUCEEDED: 1229 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1230 sm_connection->sm_le_db_index = matched_device_id; 1231 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1232 if (sm_connection->sm_role) break; 1233 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1234 sm_connection->sm_security_request_received = 0; 1235 sm_connection->sm_bonding_requested = 0; 1236 le_device_db_encryption_get(sm_connection->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 1237 if (ediv){ 1238 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1239 } else { 1240 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1241 } 1242 break; 1243 case ADDRESS_RESOLUTION_FAILED: 1244 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1245 if (sm_connection->sm_role) break; 1246 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1247 sm_connection->sm_security_request_received = 0; 1248 sm_connection->sm_bonding_requested = 0; 1249 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1250 break; 1251 } 1252 break; 1253 default: 1254 break; 1255 } 1256 1257 switch (event){ 1258 case ADDRESS_RESOLUTION_SUCEEDED: 1259 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1260 break; 1261 case ADDRESS_RESOLUTION_FAILED: 1262 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1263 break; 1264 } 1265 } 1266 1267 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1268 1269 int le_db_index = -1; 1270 1271 // lookup device based on IRK 1272 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1273 int i; 1274 for (i=0; i < le_device_db_count(); i++){ 1275 sm_key_t irk; 1276 bd_addr_t address; 1277 int address_type; 1278 le_device_db_info(i, &address_type, address, irk); 1279 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1280 log_info("sm: device found for IRK, updating"); 1281 le_db_index = i; 1282 break; 1283 } 1284 } 1285 } 1286 1287 // if not found, lookup via public address if possible 1288 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1289 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1290 int i; 1291 for (i=0; i < le_device_db_count(); i++){ 1292 bd_addr_t address; 1293 int address_type; 1294 le_device_db_info(i, &address_type, address, NULL); 1295 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1296 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1297 log_info("sm: device found for public address, updating"); 1298 le_db_index = i; 1299 break; 1300 } 1301 } 1302 } 1303 1304 // if not found, add to db 1305 if (le_db_index < 0) { 1306 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1307 } 1308 1309 if (le_db_index >= 0){ 1310 le_device_db_local_counter_set(le_db_index, 0); 1311 1312 // store local CSRK 1313 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1314 log_info("sm: store local CSRK"); 1315 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1316 le_device_db_local_counter_set(le_db_index, 0); 1317 } 1318 1319 // store remote CSRK 1320 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1321 log_info("sm: store remote CSRK"); 1322 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1323 le_device_db_remote_counter_set(le_db_index, 0); 1324 } 1325 1326 // store encryption information 1327 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION 1328 && setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 1329 log_info("sm: set encryption information (key size %u, authenticatd %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1330 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1331 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1332 } 1333 } 1334 1335 // keep le_db_index 1336 sm_conn->sm_le_db_index = le_db_index; 1337 } 1338 1339 static void sm_run(void){ 1340 1341 btstack_linked_list_iterator_t it; 1342 1343 // assert that we can send at least commands 1344 if (!hci_can_send_command_packet_now()) return; 1345 1346 // 1347 // non-connection related behaviour 1348 // 1349 1350 // distributed key generation 1351 switch (dkg_state){ 1352 case DKG_CALC_IRK: 1353 // already busy? 1354 if (sm_aes128_state == SM_AES128_IDLE) { 1355 // IRK = d1(IR, 1, 0) 1356 sm_key_t d1_prime; 1357 sm_d1_d_prime(1, 0, d1_prime); // plaintext 1358 dkg_next_state(); 1359 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1360 return; 1361 } 1362 break; 1363 case DKG_CALC_DHK: 1364 // already busy? 1365 if (sm_aes128_state == SM_AES128_IDLE) { 1366 // DHK = d1(IR, 3, 0) 1367 sm_key_t d1_prime; 1368 sm_d1_d_prime(3, 0, d1_prime); // plaintext 1369 dkg_next_state(); 1370 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1371 return; 1372 } 1373 break; 1374 default: 1375 break; 1376 } 1377 1378 // random address updates 1379 switch (rau_state){ 1380 case RAU_GET_RANDOM: 1381 rau_next_state(); 1382 sm_random_start(NULL); 1383 return; 1384 case RAU_GET_ENC: 1385 // already busy? 1386 if (sm_aes128_state == SM_AES128_IDLE) { 1387 sm_key_t r_prime; 1388 sm_ah_r_prime(sm_random_address, r_prime); 1389 rau_next_state(); 1390 sm_aes128_start(sm_persistent_irk, r_prime, NULL); 1391 return; 1392 } 1393 break; 1394 case RAU_SET_ADDRESS: 1395 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1396 rau_state = RAU_IDLE; 1397 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1398 return; 1399 default: 1400 break; 1401 } 1402 1403 // CMAC 1404 switch (sm_cmac_state){ 1405 case CMAC_CALC_SUBKEYS: 1406 case CMAC_CALC_MI: 1407 case CMAC_CALC_MLAST: 1408 // already busy? 1409 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1410 sm_cmac_handle_aes_engine_ready(); 1411 return; 1412 default: 1413 break; 1414 } 1415 1416 // CSRK Lookup 1417 // -- if csrk lookup ready, find connection that require csrk lookup 1418 if (sm_address_resolution_idle()){ 1419 hci_connections_get_iterator(&it); 1420 while(btstack_linked_list_iterator_has_next(&it)){ 1421 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1422 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1423 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1424 // and start lookup 1425 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); 1426 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1427 break; 1428 } 1429 } 1430 } 1431 1432 // -- if csrk lookup ready, resolved addresses for received addresses 1433 if (sm_address_resolution_idle()) { 1434 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1435 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1436 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1437 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1438 btstack_memory_sm_lookup_entry_free(entry); 1439 } 1440 } 1441 1442 // -- Continue with CSRK device lookup by public or resolvable private address 1443 if (!sm_address_resolution_idle()){ 1444 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_count()); 1445 while (sm_address_resolution_test < le_device_db_count()){ 1446 int addr_type; 1447 bd_addr_t addr; 1448 sm_key_t irk; 1449 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1450 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1451 1452 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1453 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1454 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1455 break; 1456 } 1457 1458 if (sm_address_resolution_addr_type == 0){ 1459 sm_address_resolution_test++; 1460 continue; 1461 } 1462 1463 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1464 1465 log_info("LE Device Lookup: calculate AH"); 1466 log_info_key("IRK", irk); 1467 1468 sm_key_t r_prime; 1469 sm_ah_r_prime(sm_address_resolution_address, r_prime); 1470 sm_address_resolution_ah_calculation_active = 1; 1471 sm_aes128_start(irk, r_prime, sm_address_resolution_context); // keep context 1472 return; 1473 } 1474 1475 if (sm_address_resolution_test >= le_device_db_count()){ 1476 log_info("LE Device Lookup: not found"); 1477 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1478 } 1479 } 1480 1481 1482 // 1483 // active connection handling 1484 // -- use loop to handle next connection if lock on setup context is released 1485 1486 while (1) { 1487 1488 // Find connections that requires setup context and make active if no other is locked 1489 hci_connections_get_iterator(&it); 1490 while(!sm_active_connection && btstack_linked_list_iterator_has_next(&it)){ 1491 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1492 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1493 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 1494 int done = 1; 1495 int err; 1496 int encryption_key_size; 1497 int authenticated; 1498 int authorized; 1499 switch (sm_connection->sm_engine_state) { 1500 case SM_RESPONDER_SEND_SECURITY_REQUEST: 1501 // send packet if possible, 1502 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 1503 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 1504 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 1505 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1506 } else { 1507 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1508 } 1509 // don't lock setup context yet 1510 done = 0; 1511 break; 1512 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 1513 sm_init_setup(sm_connection); 1514 // recover pairing request 1515 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 1516 err = sm_stk_generation_init(sm_connection); 1517 if (err){ 1518 setup->sm_pairing_failed_reason = err; 1519 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1520 break; 1521 } 1522 sm_timeout_start(sm_connection); 1523 // generate random number first, if we need to show passkey 1524 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 1525 sm_connection->sm_engine_state = SM_PH2_GET_RANDOM_TK; 1526 break; 1527 } 1528 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 1529 break; 1530 case SM_INITIATOR_PH0_HAS_LTK: 1531 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1532 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1533 &encryption_key_size, &authenticated, &authorized); 1534 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1535 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1536 sm_connection->sm_connection_authenticated = authenticated; 1537 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1538 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 1539 break; 1540 case SM_RESPONDER_PH0_RECEIVED_LTK: 1541 // re-establish previously used LTK using Rand and EDIV 1542 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1543 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1544 // re-establish used key encryption size 1545 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1546 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1547 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1548 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1549 log_info("sm: received ltk request with key size %u, authenticated %u", 1550 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1551 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1552 break; 1553 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 1554 sm_init_setup(sm_connection); 1555 sm_timeout_start(sm_connection); 1556 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 1557 break; 1558 default: 1559 done = 0; 1560 break; 1561 } 1562 if (done){ 1563 sm_active_connection = sm_connection->sm_handle; 1564 log_info("sm: connection 0x%04x locked setup context as %s", sm_active_connection, sm_connection->sm_role ? "responder" : "initiator"); 1565 } 1566 } 1567 1568 // 1569 // active connection handling 1570 // 1571 1572 if (sm_active_connection == 0) return; 1573 1574 // assert that we could send a SM PDU - not needed for all of the following 1575 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 1576 l2cap_request_can_send_fix_channel_now_event(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1577 return; 1578 } 1579 1580 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection); 1581 if (!connection) return; 1582 1583 sm_key_t plaintext; 1584 int key_distribution_flags; 1585 1586 log_info("sm_run: state %u", connection->sm_engine_state); 1587 1588 // responding state 1589 switch (connection->sm_engine_state){ 1590 1591 // general 1592 case SM_GENERAL_SEND_PAIRING_FAILED: { 1593 uint8_t buffer[2]; 1594 buffer[0] = SM_CODE_PAIRING_FAILED; 1595 buffer[1] = setup->sm_pairing_failed_reason; 1596 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 1597 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1598 sm_done_for_handle(connection->sm_handle); 1599 break; 1600 } 1601 1602 // initiator side 1603 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 1604 sm_key_t peer_ltk_flipped; 1605 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 1606 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 1607 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 1608 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 1609 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 1610 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 1611 return; 1612 } 1613 1614 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 1615 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 1616 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 1617 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 1618 sm_timeout_reset(connection); 1619 break; 1620 1621 // responder side 1622 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 1623 connection->sm_engine_state = SM_RESPONDER_IDLE; 1624 hci_send_cmd(&hci_le_long_term_key_negative_reply, connection->sm_handle); 1625 return; 1626 1627 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1628 case SM_PH2_SEND_PUBLIC_KEY_COMMAND: { 1629 uint8_t buffer[65]; 1630 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 1631 // 1632 #ifdef USE_MBEDTLS_FOR_ECDH 1633 uint8_t value[32]; 1634 mbedtls_mpi_write_binary(&le_keypair.Q.X, value, sizeof(value)); 1635 reverse_256(value, &buffer[1]); 1636 mbedtls_mpi_write_binary(&le_keypair.Q.Y, value, sizeof(value)); 1637 reverse_256(value, &buffer[33]); 1638 #endif 1639 // TODO: use random generator to generate nonce 1640 1641 // generate 128-bit nonce 1642 int i; 1643 for (i=0;i<16;i++){ 1644 setup->sm_local_nonce[i] = rand() & 0xff; 1645 } 1646 1647 // stk generation method 1648 // passkey entry: notify app to show passkey or to request passkey 1649 switch (setup->sm_stk_generation_method){ 1650 case JUST_WORKS: 1651 case NK_BOTH_INPUT: 1652 if (connection->sm_role){ 1653 connection->sm_engine_state = SM_PH2_SEND_CONFIRMATION; 1654 } else { 1655 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PUBLIC_KEY_COMMAND; 1656 } 1657 break; 1658 case PK_INIT_INPUT: 1659 case PK_RESP_INPUT: 1660 case OK_BOTH_INPUT: 1661 // hack for testing: assume user entered '000000' 1662 // memset(setup->sm_tk, 0, 16); 1663 memcpy(setup->sm_ra, setup->sm_tk, 16); 1664 memcpy(setup->sm_rb, setup->sm_tk, 16); 1665 setup->sm_passkey_bit = 0; 1666 if (connection->sm_role){ 1667 // responder 1668 connection->sm_engine_state = SM_PH2_W4_CONFIRMATION; 1669 } else { 1670 // initiator 1671 connection->sm_engine_state = SM_PH2_SEND_CONFIRMATION; 1672 } 1673 sm_trigger_user_response(connection); 1674 break; 1675 case OOB: 1676 // TODO: implement SC OOB 1677 break; 1678 } 1679 1680 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1681 sm_timeout_reset(connection); 1682 break; 1683 } 1684 case SM_PH2_SEND_CONFIRMATION: { 1685 uint8_t buffer[17]; 1686 buffer[0] = SM_CODE_PAIRING_CONFIRM; 1687 #ifdef USE_MBEDTLS_FOR_ECDH 1688 uint8_t z = 0; 1689 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1690 // some form of passkey 1691 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1692 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1693 setup->sm_passkey_bit++; 1694 } 1695 1696 // TODO: use AES Engine to calculate commitment value using f4 1697 uint8_t value[32]; 1698 mbedtls_mpi_write_binary(&le_keypair.Q.X, value, sizeof(value)); 1699 sm_key_t confirm_value; 1700 f4(confirm_value, value, setup->sm_peer_qx, setup->sm_local_nonce, z); 1701 reverse_128(confirm_value, &buffer[1]); 1702 #endif 1703 if (connection->sm_role){ 1704 connection->sm_engine_state = SM_PH2_W4_PAIRING_RANDOM; 1705 } else { 1706 // TODO: set next state for initiator depending on stk generation method 1707 log_error("SC, next state initiator, only for passkey entry needed"); 1708 } 1709 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1710 sm_timeout_reset(connection); 1711 break; 1712 } 1713 case SM_PH2_SEND_PAIRING_RANDOM_SC: { 1714 uint8_t buffer[17]; 1715 buffer[0] = SM_CODE_PAIRING_RANDOM; 1716 reverse_128(setup->sm_local_nonce, &buffer[1]); 1717 1718 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT && setup->sm_passkey_bit < 20){ 1719 if (connection->sm_role){ 1720 // responder 1721 connection->sm_engine_state = SM_PH2_W4_CONFIRMATION; 1722 } else { 1723 // initiator 1724 // TODO: next initiator state 1725 } 1726 } else { 1727 if (connection->sm_role){ 1728 // responder 1729 connection->sm_engine_state = SM_PH2_W4_DHKEY_CHECK_COMMAND; 1730 if (setup->sm_stk_generation_method == NK_BOTH_INPUT){ 1731 // calc Vb if numeric comparison 1732 // TODO: use AES Engine to calculate g2 1733 uint8_t value[32]; 1734 mbedtls_mpi_write_binary(&le_keypair.Q.X, value, sizeof(value)); 1735 uint32_t vb = g2(setup->sm_peer_qx, value, setup->sm_peer_nonce, setup->sm_local_nonce) % 1000000; 1736 big_endian_store_32(setup->sm_tk, 12, vb); 1737 sm_trigger_user_response(connection); 1738 } 1739 } else { 1740 // initiator 1741 connection->sm_engine_state = SM_PH2_W4_PAIRING_RANDOM; 1742 } 1743 } 1744 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1745 sm_timeout_reset(connection); 1746 break; 1747 } 1748 case SM_PH2_SEND_DHKEY_CHECK_COMMAND: { 1749 1750 uint8_t buffer[17]; 1751 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 1752 #ifdef USE_MBEDTLS_FOR_ECDH 1753 // calculate DHKEY 1754 mbedtls_ecp_group grp; 1755 mbedtls_ecp_group_init( &grp ); 1756 mbedtls_ecp_group_load(&grp, MBEDTLS_ECP_DP_SECP256R1); 1757 mbedtls_ecp_point Q; 1758 mbedtls_ecp_point_init( &Q ); 1759 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 1760 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 1761 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 1762 1763 // da * Pb 1764 mbedtls_ecp_point DH; 1765 mbedtls_ecp_point_init( &DH ); 1766 mbedtls_ecp_mul(&grp, &DH, &le_keypair.d, &Q, NULL, NULL); 1767 sm_key256_t dhkey; 1768 mbedtls_mpi_write_binary(&DH.X, dhkey, 32); 1769 log_info("dhkey"); 1770 log_info_hexdump(dhkey, 32); 1771 1772 // calculate LTK + MacKey 1773 sm_key256_t ltk_mackey; 1774 sm_key56_t bd_addr_master, bd_addr_slave; 1775 bd_addr_master[0] = setup->sm_m_addr_type; 1776 bd_addr_slave[0] = setup->sm_s_addr_type; 1777 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1778 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1779 if (connection->sm_role){ 1780 // responder 1781 f5(ltk_mackey, dhkey, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1782 } else { 1783 // initiator 1784 f5(ltk_mackey, dhkey, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1785 } 1786 // store LTK 1787 memcpy(setup->sm_ltk, <k_mackey[16], 16); 1788 1789 // calc DHKCheck 1790 sm_key_t mackey; 1791 memcpy(mackey, <k_mackey[0], 16); 1792 1793 // TODO: checks 1794 1795 uint8_t iocap_a[3]; 1796 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1797 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1798 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1799 uint8_t iocap_b[3]; 1800 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1801 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1802 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1803 if (connection->sm_role){ 1804 // responder 1805 f6(setup->sm_local_dhkey_check, mackey, setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1806 } else { 1807 // initiator 1808 f6(setup->sm_local_dhkey_check, mackey, setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1809 } 1810 #endif 1811 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 1812 if (connection->sm_role){ 1813 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST_SC; 1814 } else { 1815 connection->sm_engine_state = SM_PH2_W4_DHKEY_CHECK_COMMAND; 1816 } 1817 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1818 sm_timeout_reset(connection); 1819 break; 1820 } 1821 1822 #endif 1823 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 1824 // echo initiator for now 1825 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 1826 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1827 1828 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 1829 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1830 if (setup->sm_use_secure_connections){ 1831 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PUBLIC_KEY_COMMAND; 1832 // skip LTK/EDIV for SC 1833 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 1834 } 1835 #endif 1836 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); 1837 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); 1838 1839 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 1840 sm_timeout_reset(connection); 1841 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 1842 if (setup->sm_stk_generation_method == JUST_WORKS){ 1843 sm_trigger_user_response(connection); 1844 } 1845 return; 1846 1847 case SM_PH2_SEND_PAIRING_RANDOM: { 1848 uint8_t buffer[17]; 1849 buffer[0] = SM_CODE_PAIRING_RANDOM; 1850 reverse_128(setup->sm_local_random, &buffer[1]); 1851 if (connection->sm_role){ 1852 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 1853 } else { 1854 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 1855 } 1856 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1857 sm_timeout_reset(connection); 1858 break; 1859 } 1860 1861 case SM_PH2_GET_RANDOM_TK: 1862 case SM_PH2_C1_GET_RANDOM_A: 1863 case SM_PH2_C1_GET_RANDOM_B: 1864 case SM_PH3_GET_RANDOM: 1865 case SM_PH3_GET_DIV: 1866 sm_next_responding_state(connection); 1867 sm_random_start(connection); 1868 return; 1869 1870 case SM_PH2_C1_GET_ENC_B: 1871 case SM_PH2_C1_GET_ENC_D: 1872 // already busy? 1873 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1874 sm_next_responding_state(connection); 1875 sm_aes128_start(setup->sm_tk, setup->sm_c1_t3_value, connection); 1876 return; 1877 1878 case SM_PH3_LTK_GET_ENC: 1879 case SM_RESPONDER_PH4_LTK_GET_ENC: 1880 // already busy? 1881 if (sm_aes128_state == SM_AES128_IDLE) { 1882 sm_key_t d_prime; 1883 sm_d1_d_prime(setup->sm_local_div, 0, d_prime); 1884 sm_next_responding_state(connection); 1885 sm_aes128_start(sm_persistent_er, d_prime, connection); 1886 return; 1887 } 1888 break; 1889 1890 case SM_PH3_CSRK_GET_ENC: 1891 // already busy? 1892 if (sm_aes128_state == SM_AES128_IDLE) { 1893 sm_key_t d_prime; 1894 sm_d1_d_prime(setup->sm_local_div, 1, d_prime); 1895 sm_next_responding_state(connection); 1896 sm_aes128_start(sm_persistent_er, d_prime, connection); 1897 return; 1898 } 1899 break; 1900 1901 case SM_PH2_C1_GET_ENC_C: 1902 // already busy? 1903 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1904 // calculate m_confirm using aes128 engine - step 1 1905 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); 1906 sm_next_responding_state(connection); 1907 sm_aes128_start(setup->sm_tk, plaintext, connection); 1908 break; 1909 case SM_PH2_C1_GET_ENC_A: 1910 // already busy? 1911 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1912 // calculate confirm using aes128 engine - step 1 1913 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); 1914 sm_next_responding_state(connection); 1915 sm_aes128_start(setup->sm_tk, plaintext, connection); 1916 break; 1917 case SM_PH2_CALC_STK: 1918 // already busy? 1919 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1920 // calculate STK 1921 if (connection->sm_role){ 1922 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, plaintext); 1923 } else { 1924 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, plaintext); 1925 } 1926 sm_next_responding_state(connection); 1927 sm_aes128_start(setup->sm_tk, plaintext, connection); 1928 break; 1929 case SM_PH3_Y_GET_ENC: 1930 // already busy? 1931 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1932 // PH3B2 - calculate Y from - enc 1933 // Y = dm(DHK, Rand) 1934 sm_dm_r_prime(setup->sm_local_rand, plaintext); 1935 sm_next_responding_state(connection); 1936 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 1937 return; 1938 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 1939 uint8_t buffer[17]; 1940 buffer[0] = SM_CODE_PAIRING_CONFIRM; 1941 reverse_128(setup->sm_local_confirm, &buffer[1]); 1942 if (connection->sm_role){ 1943 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 1944 } else { 1945 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 1946 } 1947 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1948 sm_timeout_reset(connection); 1949 return; 1950 } 1951 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 1952 sm_key_t stk_flipped; 1953 reverse_128(setup->sm_ltk, stk_flipped); 1954 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 1955 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 1956 return; 1957 } 1958 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 1959 sm_key_t stk_flipped; 1960 reverse_128(setup->sm_ltk, stk_flipped); 1961 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 1962 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 1963 return; 1964 } 1965 case SM_RESPONDER_PH4_SEND_LTK: { 1966 sm_key_t ltk_flipped; 1967 reverse_128(setup->sm_ltk, ltk_flipped); 1968 connection->sm_engine_state = SM_RESPONDER_IDLE; 1969 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 1970 return; 1971 } 1972 case SM_RESPONDER_PH4_Y_GET_ENC: 1973 // already busy? 1974 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1975 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 1976 // Y = dm(DHK, Rand) 1977 sm_dm_r_prime(setup->sm_local_rand, plaintext); 1978 sm_next_responding_state(connection); 1979 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 1980 return; 1981 1982 case SM_PH3_DISTRIBUTE_KEYS: 1983 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 1984 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 1985 uint8_t buffer[17]; 1986 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 1987 reverse_128(setup->sm_ltk, &buffer[1]); 1988 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1989 sm_timeout_reset(connection); 1990 return; 1991 } 1992 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 1993 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 1994 uint8_t buffer[11]; 1995 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 1996 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 1997 reverse_64(setup->sm_local_rand, &buffer[3]); 1998 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1999 sm_timeout_reset(connection); 2000 return; 2001 } 2002 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2003 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2004 uint8_t buffer[17]; 2005 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2006 reverse_128(sm_persistent_irk, &buffer[1]); 2007 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2008 sm_timeout_reset(connection); 2009 return; 2010 } 2011 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2012 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2013 bd_addr_t local_address; 2014 uint8_t buffer[8]; 2015 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2016 gap_advertisements_get_address(&buffer[1], local_address); 2017 reverse_bd_addr(local_address, &buffer[2]); 2018 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2019 sm_timeout_reset(connection); 2020 return; 2021 } 2022 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2023 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2024 2025 // hack to reproduce test runs 2026 if (test_use_fixed_local_csrk){ 2027 memset(setup->sm_local_csrk, 0xcc, 16); 2028 } 2029 2030 uint8_t buffer[17]; 2031 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2032 reverse_128(setup->sm_local_csrk, &buffer[1]); 2033 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2034 sm_timeout_reset(connection); 2035 return; 2036 } 2037 2038 // keys are sent 2039 if (connection->sm_role){ 2040 // slave -> receive master keys if any 2041 if (sm_key_distribution_all_received(connection)){ 2042 sm_key_distribution_handle_all_received(connection); 2043 connection->sm_engine_state = SM_RESPONDER_IDLE; 2044 sm_done_for_handle(connection->sm_handle); 2045 } else { 2046 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2047 } 2048 } else { 2049 // master -> all done 2050 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2051 sm_done_for_handle(connection->sm_handle); 2052 } 2053 break; 2054 2055 default: 2056 break; 2057 } 2058 2059 // check again if active connection was released 2060 if (sm_active_connection) break; 2061 } 2062 } 2063 2064 // note: aes engine is ready as we just got the aes result 2065 static void sm_handle_encryption_result(uint8_t * data){ 2066 2067 sm_aes128_state = SM_AES128_IDLE; 2068 2069 if (sm_address_resolution_ah_calculation_active){ 2070 sm_address_resolution_ah_calculation_active = 0; 2071 // compare calulated address against connecting device 2072 uint8_t hash[3]; 2073 reverse_24(data, hash); 2074 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2075 log_info("LE Device Lookup: matched resolvable private address"); 2076 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2077 return; 2078 } 2079 // no match, try next 2080 sm_address_resolution_test++; 2081 return; 2082 } 2083 2084 switch (dkg_state){ 2085 case DKG_W4_IRK: 2086 reverse_128(data, sm_persistent_irk); 2087 log_info_key("irk", sm_persistent_irk); 2088 dkg_next_state(); 2089 return; 2090 case DKG_W4_DHK: 2091 reverse_128(data, sm_persistent_dhk); 2092 log_info_key("dhk", sm_persistent_dhk); 2093 dkg_next_state(); 2094 // SM Init Finished 2095 return; 2096 default: 2097 break; 2098 } 2099 2100 switch (rau_state){ 2101 case RAU_W4_ENC: 2102 reverse_24(data, &sm_random_address[3]); 2103 rau_next_state(); 2104 return; 2105 default: 2106 break; 2107 } 2108 2109 switch (sm_cmac_state){ 2110 case CMAC_W4_SUBKEYS: 2111 case CMAC_W4_MI: 2112 case CMAC_W4_MLAST: 2113 { 2114 sm_key_t t; 2115 reverse_128(data, t); 2116 sm_cmac_handle_encryption_result(t); 2117 } 2118 return; 2119 default: 2120 break; 2121 } 2122 2123 // retrieve sm_connection provided to sm_aes128_start_encryption 2124 sm_connection_t * connection = (sm_connection_t*) sm_aes128_context; 2125 if (!connection) return; 2126 switch (connection->sm_engine_state){ 2127 case SM_PH2_C1_W4_ENC_A: 2128 case SM_PH2_C1_W4_ENC_C: 2129 { 2130 sm_key_t t2; 2131 reverse_128(data, t2); 2132 sm_c1_t3(t2, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2133 } 2134 sm_next_responding_state(connection); 2135 return; 2136 case SM_PH2_C1_W4_ENC_B: 2137 reverse_128(data, setup->sm_local_confirm); 2138 log_info_key("c1!", setup->sm_local_confirm); 2139 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2140 return; 2141 case SM_PH2_C1_W4_ENC_D: 2142 { 2143 sm_key_t peer_confirm_test; 2144 reverse_128(data, peer_confirm_test); 2145 log_info_key("c1!", peer_confirm_test); 2146 if (memcmp(setup->sm_peer_confirm, peer_confirm_test, 16) != 0){ 2147 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2148 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2149 return; 2150 } 2151 if (connection->sm_role){ 2152 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2153 } else { 2154 connection->sm_engine_state = SM_PH2_CALC_STK; 2155 } 2156 } 2157 return; 2158 case SM_PH2_W4_STK: 2159 reverse_128(data, setup->sm_ltk); 2160 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2161 log_info_key("stk", setup->sm_ltk); 2162 if (connection->sm_role){ 2163 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2164 } else { 2165 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2166 } 2167 return; 2168 case SM_PH3_Y_W4_ENC:{ 2169 sm_key_t y128; 2170 reverse_128(data, y128); 2171 setup->sm_local_y = big_endian_read_16(y128, 14); 2172 log_info_hex16("y", setup->sm_local_y); 2173 // PH3B3 - calculate EDIV 2174 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2175 log_info_hex16("ediv", setup->sm_local_ediv); 2176 // PH3B4 - calculate LTK - enc 2177 // LTK = d1(ER, DIV, 0)) 2178 connection->sm_engine_state = SM_PH3_LTK_GET_ENC; 2179 return; 2180 } 2181 case SM_RESPONDER_PH4_Y_W4_ENC:{ 2182 sm_key_t y128; 2183 reverse_128(data, y128); 2184 setup->sm_local_y = big_endian_read_16(y128, 14); 2185 log_info_hex16("y", setup->sm_local_y); 2186 2187 // PH3B3 - calculate DIV 2188 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2189 log_info_hex16("ediv", setup->sm_local_ediv); 2190 // PH3B4 - calculate LTK - enc 2191 // LTK = d1(ER, DIV, 0)) 2192 connection->sm_engine_state = SM_RESPONDER_PH4_LTK_GET_ENC; 2193 return; 2194 } 2195 case SM_PH3_LTK_W4_ENC: 2196 reverse_128(data, setup->sm_ltk); 2197 log_info_key("ltk", setup->sm_ltk); 2198 // calc CSRK next 2199 connection->sm_engine_state = SM_PH3_CSRK_GET_ENC; 2200 return; 2201 case SM_PH3_CSRK_W4_ENC: 2202 reverse_128(data, setup->sm_local_csrk); 2203 log_info_key("csrk", setup->sm_local_csrk); 2204 if (setup->sm_key_distribution_send_set){ 2205 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2206 } else { 2207 // no keys to send, just continue 2208 if (connection->sm_role){ 2209 // slave -> receive master keys 2210 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2211 } else { 2212 // master -> all done 2213 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2214 sm_done_for_handle(connection->sm_handle); 2215 } 2216 } 2217 return; 2218 case SM_RESPONDER_PH4_LTK_W4_ENC: 2219 reverse_128(data, setup->sm_ltk); 2220 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2221 log_info_key("ltk", setup->sm_ltk); 2222 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK; 2223 return; 2224 default: 2225 break; 2226 } 2227 } 2228 2229 // note: random generator is ready. this doesn NOT imply that aes engine is unused! 2230 static void sm_handle_random_result(uint8_t * data){ 2231 2232 switch (rau_state){ 2233 case RAU_W4_RANDOM: 2234 // non-resolvable vs. resolvable 2235 switch (gap_random_adress_type){ 2236 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2237 // resolvable: use random as prand and calc address hash 2238 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2239 memcpy(sm_random_address, data, 3); 2240 sm_random_address[0] &= 0x3f; 2241 sm_random_address[0] |= 0x40; 2242 rau_state = RAU_GET_ENC; 2243 break; 2244 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2245 default: 2246 // "The two most significant bits of the address shall be equal to ‘0’"" 2247 memcpy(sm_random_address, data, 6); 2248 sm_random_address[0] &= 0x3f; 2249 rau_state = RAU_SET_ADDRESS; 2250 break; 2251 } 2252 return; 2253 default: 2254 break; 2255 } 2256 2257 // retrieve sm_connection provided to sm_random_start 2258 sm_connection_t * connection = (sm_connection_t *) sm_random_context; 2259 if (!connection) return; 2260 switch (connection->sm_engine_state){ 2261 case SM_PH2_W4_RANDOM_TK: 2262 { 2263 // map random to 0-999999 without speding much cycles on a modulus operation 2264 uint32_t tk = little_endian_read_32(data,0); 2265 tk = tk & 0xfffff; // 1048575 2266 if (tk >= 999999){ 2267 tk = tk - 999999; 2268 } 2269 sm_reset_tk(); 2270 big_endian_store_32(setup->sm_tk, 12, tk); 2271 if (connection->sm_role){ 2272 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2273 } else { 2274 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2275 sm_trigger_user_response(connection); 2276 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2277 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2278 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 2279 } 2280 } 2281 return; 2282 } 2283 case SM_PH2_C1_W4_RANDOM_A: 2284 memcpy(&setup->sm_local_random[0], data, 8); // random endinaness 2285 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_B; 2286 return; 2287 case SM_PH2_C1_W4_RANDOM_B: 2288 memcpy(&setup->sm_local_random[8], data, 8); // random endinaness 2289 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2290 return; 2291 case SM_PH3_W4_RANDOM: 2292 reverse_64(data, setup->sm_local_rand); 2293 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2294 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2295 // no db for authenticated flag hack: store flag in bit 4 of LSB 2296 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2297 connection->sm_engine_state = SM_PH3_GET_DIV; 2298 return; 2299 case SM_PH3_W4_DIV: 2300 // use 16 bit from random value as div 2301 setup->sm_local_div = big_endian_read_16(data, 0); 2302 log_info_hex16("div", setup->sm_local_div); 2303 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2304 return; 2305 default: 2306 break; 2307 } 2308 } 2309 2310 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2311 2312 sm_connection_t * sm_conn; 2313 hci_con_handle_t con_handle; 2314 2315 switch (packet_type) { 2316 2317 case HCI_EVENT_PACKET: 2318 switch (hci_event_packet_get_type(packet)) { 2319 2320 case BTSTACK_EVENT_STATE: 2321 // bt stack activated, get started 2322 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2323 log_info("HCI Working!"); 2324 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 2325 rau_state = RAU_IDLE; 2326 sm_run(); 2327 } 2328 break; 2329 2330 case HCI_EVENT_LE_META: 2331 switch (packet[2]) { 2332 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2333 2334 log_info("sm: connected"); 2335 2336 if (packet[3]) return; // connection failed 2337 2338 con_handle = little_endian_read_16(packet, 4); 2339 sm_conn = sm_get_connection_for_handle(con_handle); 2340 if (!sm_conn) break; 2341 2342 sm_conn->sm_handle = con_handle; 2343 sm_conn->sm_role = packet[6]; 2344 sm_conn->sm_peer_addr_type = packet[7]; 2345 reverse_bd_addr(&packet[8], 2346 sm_conn->sm_peer_address); 2347 2348 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2349 2350 // reset security properties 2351 sm_conn->sm_connection_encrypted = 0; 2352 sm_conn->sm_connection_authenticated = 0; 2353 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2354 sm_conn->sm_le_db_index = -1; 2355 2356 // prepare CSRK lookup (does not involve setup) 2357 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2358 2359 // just connected -> everything else happens in sm_run() 2360 if (sm_conn->sm_role){ 2361 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2362 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2363 if (sm_slave_request_security) { 2364 // request security if requested by app 2365 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2366 } else { 2367 // otherwise, wait for pairing request 2368 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2369 } 2370 } 2371 break; 2372 } else { 2373 // master 2374 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2375 } 2376 break; 2377 2378 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2379 con_handle = little_endian_read_16(packet, 3); 2380 sm_conn = sm_get_connection_for_handle(con_handle); 2381 if (!sm_conn) break; 2382 2383 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2384 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2385 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2386 break; 2387 } 2388 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST_SC){ 2389 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2390 break; 2391 } 2392 2393 // assume that we don't have a LTK for ediv == 0 and random == null 2394 if (little_endian_read_16(packet, 13) == 0 && sm_is_null_random(&packet[5])){ 2395 log_info("LTK Request: ediv & random are empty"); 2396 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 2397 break; 2398 } 2399 2400 // store rand and ediv 2401 reverse_64(&packet[5], sm_conn->sm_local_rand); 2402 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2403 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK; 2404 break; 2405 2406 default: 2407 break; 2408 } 2409 break; 2410 2411 case HCI_EVENT_ENCRYPTION_CHANGE: 2412 con_handle = little_endian_read_16(packet, 3); 2413 sm_conn = sm_get_connection_for_handle(con_handle); 2414 if (!sm_conn) break; 2415 2416 sm_conn->sm_connection_encrypted = packet[5]; 2417 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 2418 sm_conn->sm_actual_encryption_key_size); 2419 log_info("event handler, state %u", sm_conn->sm_engine_state); 2420 if (!sm_conn->sm_connection_encrypted) break; 2421 // continue if part of initial pairing 2422 switch (sm_conn->sm_engine_state){ 2423 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2424 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2425 sm_done_for_handle(sm_conn->sm_handle); 2426 break; 2427 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2428 if (sm_conn->sm_role){ 2429 // slave 2430 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2431 } else { 2432 // master 2433 if (sm_key_distribution_all_received(sm_conn)){ 2434 // skip receiving keys as there are none 2435 sm_key_distribution_handle_all_received(sm_conn); 2436 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2437 } else { 2438 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2439 } 2440 } 2441 break; 2442 default: 2443 break; 2444 } 2445 break; 2446 2447 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 2448 con_handle = little_endian_read_16(packet, 3); 2449 sm_conn = sm_get_connection_for_handle(con_handle); 2450 if (!sm_conn) break; 2451 2452 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 2453 log_info("event handler, state %u", sm_conn->sm_engine_state); 2454 // continue if part of initial pairing 2455 switch (sm_conn->sm_engine_state){ 2456 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2457 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2458 sm_done_for_handle(sm_conn->sm_handle); 2459 break; 2460 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2461 if (sm_conn->sm_role){ 2462 // slave 2463 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2464 } else { 2465 // master 2466 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2467 } 2468 break; 2469 default: 2470 break; 2471 } 2472 break; 2473 2474 2475 case HCI_EVENT_DISCONNECTION_COMPLETE: 2476 con_handle = little_endian_read_16(packet, 3); 2477 sm_done_for_handle(con_handle); 2478 sm_conn = sm_get_connection_for_handle(con_handle); 2479 if (!sm_conn) break; 2480 2481 // delete stored bonding on disconnect with authentication failure in ph0 2482 if (sm_conn->sm_role == 0 2483 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 2484 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 2485 le_device_db_remove(sm_conn->sm_le_db_index); 2486 } 2487 2488 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 2489 sm_conn->sm_handle = 0; 2490 break; 2491 2492 case HCI_EVENT_COMMAND_COMPLETE: 2493 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 2494 sm_handle_encryption_result(&packet[6]); 2495 break; 2496 } 2497 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 2498 sm_handle_random_result(&packet[6]); 2499 break; 2500 } 2501 break; 2502 default: 2503 break; 2504 } 2505 break; 2506 default: 2507 break; 2508 } 2509 2510 sm_run(); 2511 } 2512 2513 static inline int sm_calc_actual_encryption_key_size(int other){ 2514 if (other < sm_min_encryption_key_size) return 0; 2515 if (other < sm_max_encryption_key_size) return other; 2516 return sm_max_encryption_key_size; 2517 } 2518 2519 /** 2520 * @return ok 2521 */ 2522 static int sm_validate_stk_generation_method(void){ 2523 // check if STK generation method is acceptable by client 2524 switch (setup->sm_stk_generation_method){ 2525 case JUST_WORKS: 2526 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 2527 case PK_RESP_INPUT: 2528 case PK_INIT_INPUT: 2529 case OK_BOTH_INPUT: 2530 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 2531 case OOB: 2532 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 2533 case NK_BOTH_INPUT: 2534 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 2535 return 1; 2536 default: 2537 return 0; 2538 } 2539 } 2540 2541 // helper for sm_pdu_handler, calls sm_run on exit 2542 static void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 2543 setup->sm_pairing_failed_reason = SM_REASON_UNSPECIFIED_REASON; 2544 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2545 sm_done_for_handle(sm_conn->sm_handle); 2546 } 2547 2548 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 2549 2550 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 2551 sm_run(); 2552 } 2553 2554 if (packet_type != SM_DATA_PACKET) return; 2555 2556 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 2557 if (!sm_conn) return; 2558 2559 if (packet[0] == SM_CODE_PAIRING_FAILED){ 2560 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2561 return; 2562 } 2563 2564 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, packet[0]); 2565 2566 int err; 2567 2568 switch (sm_conn->sm_engine_state){ 2569 2570 // a sm timeout requries a new physical connection 2571 case SM_GENERAL_TIMEOUT: 2572 return; 2573 2574 // Initiator 2575 case SM_INITIATOR_CONNECTED: 2576 if ((packet[0] != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 2577 sm_pdu_received_in_wrong_state(sm_conn); 2578 break; 2579 } 2580 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 2581 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 2582 break; 2583 } 2584 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 2585 uint16_t ediv; 2586 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 2587 if (ediv){ 2588 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 2589 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 2590 } else { 2591 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 2592 } 2593 break; 2594 } 2595 // otherwise, store security request 2596 sm_conn->sm_security_request_received = 1; 2597 break; 2598 2599 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 2600 if (packet[0] != SM_CODE_PAIRING_RESPONSE){ 2601 sm_pdu_received_in_wrong_state(sm_conn); 2602 break; 2603 } 2604 // store pairing request 2605 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 2606 err = sm_stk_generation_init(sm_conn); 2607 if (err){ 2608 setup->sm_pairing_failed_reason = err; 2609 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2610 break; 2611 } 2612 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2613 if (setup->sm_use_secure_connections){ 2614 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2615 if (setup->sm_stk_generation_method == JUST_WORKS){ 2616 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2617 sm_trigger_user_response(sm_conn); 2618 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2619 sm_conn->sm_engine_state = SM_PH2_SEND_PUBLIC_KEY_COMMAND; 2620 } 2621 } else { 2622 sm_conn->sm_engine_state = SM_PH2_SEND_PUBLIC_KEY_COMMAND; 2623 } 2624 break; 2625 } 2626 #endif 2627 // generate random number first, if we need to show passkey 2628 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 2629 sm_conn->sm_engine_state = SM_PH2_GET_RANDOM_TK; 2630 break; 2631 } 2632 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2633 sm_trigger_user_response(sm_conn); 2634 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2635 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2636 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 2637 } 2638 break; 2639 2640 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 2641 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 2642 sm_pdu_received_in_wrong_state(sm_conn); 2643 break; 2644 } 2645 2646 // store s_confirm 2647 reverse_128(&packet[1], setup->sm_peer_confirm); 2648 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2649 break; 2650 2651 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 2652 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 2653 sm_pdu_received_in_wrong_state(sm_conn); 2654 break;; 2655 } 2656 2657 // received random value 2658 reverse_128(&packet[1], setup->sm_peer_random); 2659 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 2660 break; 2661 2662 // Responder 2663 case SM_RESPONDER_IDLE: 2664 case SM_RESPONDER_SEND_SECURITY_REQUEST: 2665 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 2666 if (packet[0] != SM_CODE_PAIRING_REQUEST){ 2667 sm_pdu_received_in_wrong_state(sm_conn); 2668 break;; 2669 } 2670 2671 // store pairing request 2672 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 2673 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 2674 break; 2675 2676 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2677 case SM_RESPONDER_PH2_W4_PUBLIC_KEY_COMMAND: 2678 if (packet[0] != SM_CODE_PAIRING_PUBLIC_KEY){ 2679 sm_pdu_received_in_wrong_state(sm_conn); 2680 break; 2681 } 2682 2683 // store public key for DH Key calculation 2684 reverse_256(&packet[01], setup->sm_peer_qx); 2685 reverse_256(&packet[33], setup->sm_peer_qy); 2686 2687 #ifdef USE_MBEDTLS_FOR_ECDH 2688 // validate public key 2689 mbedtls_ecp_group grp; 2690 mbedtls_ecp_group_init( &grp ); 2691 mbedtls_ecp_group_load(&grp, MBEDTLS_ECP_DP_SECP256R1); 2692 2693 mbedtls_ecp_point Q; 2694 mbedtls_ecp_point_init( &Q ); 2695 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 2696 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 2697 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 2698 err = mbedtls_ecp_check_pubkey(&grp, &Q); 2699 if (err){ 2700 log_error("sm: peer public key invalid %x", err); 2701 // uses "unspecified reason", there is no "public key invalid" error code 2702 sm_pdu_received_in_wrong_state(sm_conn); 2703 break; 2704 } 2705 #endif 2706 if (sm_conn->sm_role){ 2707 // responder 2708 sm_conn->sm_engine_state = SM_PH2_SEND_PUBLIC_KEY_COMMAND; 2709 } else { 2710 // initiator 2711 sm_conn->sm_engine_state = SM_PH2_W4_CONFIRMATION; 2712 } 2713 break; 2714 2715 case SM_PH2_W4_CONFIRMATION: 2716 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 2717 sm_pdu_received_in_wrong_state(sm_conn); 2718 break; 2719 } 2720 // received confirm value 2721 reverse_128(&packet[1], setup->sm_peer_confirm); 2722 2723 if (sm_conn->sm_role){ 2724 // responder 2725 sm_conn->sm_engine_state = SM_PH2_SEND_CONFIRMATION; 2726 } else { 2727 // initiator 2728 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM_SC; 2729 } 2730 break; 2731 2732 case SM_PH2_W4_PAIRING_RANDOM: 2733 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 2734 sm_pdu_received_in_wrong_state(sm_conn); 2735 break; 2736 } 2737 2738 // received random value 2739 reverse_128(&packet[1], setup->sm_peer_nonce); 2740 2741 if (sm_conn->sm_role){ 2742 // Responder 2743 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM_SC; 2744 } else { 2745 // Initiator role 2746 sm_conn->sm_engine_state = SM_PH2_SEND_DHKEY_CHECK_COMMAND; 2747 if (setup->sm_stk_generation_method == NK_BOTH_INPUT){ 2748 2749 // TODO: check if Cb = f4(Pkb, Pka, Nb, 0) 2750 2751 // calc Va if numeric comparison 2752 // TODO: use AES Engine to calculate g2 2753 uint8_t value[32]; 2754 mbedtls_mpi_write_binary(&le_keypair.Q.X, value, sizeof(value)); 2755 uint32_t va = g2(value, setup->sm_peer_qx, setup->sm_local_nonce, setup->sm_peer_nonce) % 1000000; 2756 big_endian_store_32(setup->sm_tk, 12, va); 2757 sm_trigger_user_response(sm_conn); 2758 } 2759 } 2760 break; 2761 2762 case SM_PH2_W4_DHKEY_CHECK_COMMAND: 2763 if (packet[0] != SM_CODE_PAIRING_DHKEY_CHECK){ 2764 sm_pdu_received_in_wrong_state(sm_conn); 2765 break; 2766 } 2767 // store DHKey Check 2768 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 2769 2770 // TODO: validate DHKey Check value 2771 2772 if (sm_conn->sm_role){ 2773 // for numeric comparison, we need to wait for user confirm 2774 if (setup->sm_stk_generation_method == NK_BOTH_INPUT && setup->sm_user_response != SM_USER_RESPONSE_CONFIRM){ 2775 sm_conn->sm_engine_state = SM_PH2_W4_USER_RESPONSE; 2776 } else { 2777 sm_conn->sm_engine_state = SM_PH2_SEND_DHKEY_CHECK_COMMAND; 2778 } 2779 } else { 2780 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2781 } 2782 break; 2783 #endif 2784 2785 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 2786 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 2787 sm_pdu_received_in_wrong_state(sm_conn); 2788 break; 2789 } 2790 2791 // received confirm value 2792 reverse_128(&packet[1], setup->sm_peer_confirm); 2793 2794 // notify client to hide shown passkey 2795 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 2796 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 2797 } 2798 2799 // handle user cancel pairing? 2800 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 2801 setup->sm_pairing_failed_reason = SM_REASON_PASSKEYT_ENTRY_FAILED; 2802 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2803 break; 2804 } 2805 2806 // wait for user action? 2807 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 2808 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2809 break; 2810 } 2811 2812 // calculate and send local_confirm 2813 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 2814 break; 2815 2816 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 2817 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 2818 sm_pdu_received_in_wrong_state(sm_conn); 2819 break;; 2820 } 2821 2822 // received random value 2823 reverse_128(&packet[1], setup->sm_peer_random); 2824 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 2825 break; 2826 2827 case SM_PH3_RECEIVE_KEYS: 2828 switch(packet[0]){ 2829 case SM_CODE_ENCRYPTION_INFORMATION: 2830 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2831 reverse_128(&packet[1], setup->sm_peer_ltk); 2832 break; 2833 2834 case SM_CODE_MASTER_IDENTIFICATION: 2835 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2836 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 2837 reverse_64(&packet[3], setup->sm_peer_rand); 2838 break; 2839 2840 case SM_CODE_IDENTITY_INFORMATION: 2841 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2842 reverse_128(&packet[1], setup->sm_peer_irk); 2843 break; 2844 2845 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 2846 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2847 setup->sm_peer_addr_type = packet[1]; 2848 reverse_bd_addr(&packet[2], setup->sm_peer_address); 2849 break; 2850 2851 case SM_CODE_SIGNING_INFORMATION: 2852 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2853 reverse_128(&packet[1], setup->sm_peer_csrk); 2854 break; 2855 default: 2856 // Unexpected PDU 2857 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 2858 break; 2859 } 2860 // done with key distribution? 2861 if (sm_key_distribution_all_received(sm_conn)){ 2862 2863 sm_key_distribution_handle_all_received(sm_conn); 2864 2865 if (sm_conn->sm_role){ 2866 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2867 sm_done_for_handle(sm_conn->sm_handle); 2868 } else { 2869 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2870 } 2871 } 2872 break; 2873 default: 2874 // Unexpected PDU 2875 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 2876 break; 2877 } 2878 2879 // try to send preparared packet 2880 sm_run(); 2881 } 2882 2883 // Security Manager Client API 2884 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data)){ 2885 sm_get_oob_data = get_oob_data_callback; 2886 } 2887 2888 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 2889 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 2890 } 2891 2892 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 2893 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 2894 } 2895 2896 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 2897 sm_min_encryption_key_size = min_size; 2898 sm_max_encryption_key_size = max_size; 2899 } 2900 2901 void sm_set_authentication_requirements(uint8_t auth_req){ 2902 sm_auth_req = auth_req; 2903 } 2904 2905 void sm_set_io_capabilities(io_capability_t io_capability){ 2906 sm_io_capabilities = io_capability; 2907 } 2908 2909 void sm_set_request_security(int enable){ 2910 sm_slave_request_security = enable; 2911 } 2912 2913 void sm_set_er(sm_key_t er){ 2914 memcpy(sm_persistent_er, er, 16); 2915 } 2916 2917 void sm_set_ir(sm_key_t ir){ 2918 memcpy(sm_persistent_ir, ir, 16); 2919 } 2920 2921 // Testing support only 2922 void sm_test_set_irk(sm_key_t irk){ 2923 memcpy(sm_persistent_irk, irk, 16); 2924 sm_persistent_irk_ready = 1; 2925 } 2926 2927 void sm_test_use_fixed_local_csrk(void){ 2928 test_use_fixed_local_csrk = 1; 2929 } 2930 2931 void sm_init(void){ 2932 // set some (BTstack default) ER and IR 2933 int i; 2934 sm_key_t er; 2935 sm_key_t ir; 2936 for (i=0;i<16;i++){ 2937 er[i] = 0x30 + i; 2938 ir[i] = 0x90 + i; 2939 } 2940 sm_set_er(er); 2941 sm_set_ir(ir); 2942 // defaults 2943 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 2944 | SM_STK_GENERATION_METHOD_OOB 2945 | SM_STK_GENERATION_METHOD_PASSKEY 2946 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 2947 2948 sm_max_encryption_key_size = 16; 2949 sm_min_encryption_key_size = 7; 2950 2951 sm_cmac_state = CMAC_IDLE; 2952 dkg_state = DKG_W4_WORKING; 2953 rau_state = RAU_W4_WORKING; 2954 sm_aes128_state = SM_AES128_IDLE; 2955 sm_address_resolution_test = -1; // no private address to resolve yet 2956 sm_address_resolution_ah_calculation_active = 0; 2957 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 2958 sm_address_resolution_general_queue = NULL; 2959 2960 gap_random_adress_update_period = 15 * 60 * 1000L; 2961 2962 sm_active_connection = 0; 2963 2964 test_use_fixed_local_csrk = 0; 2965 2966 // register for HCI Events from HCI 2967 hci_event_callback_registration.callback = &sm_event_packet_handler; 2968 hci_add_event_handler(&hci_event_callback_registration); 2969 2970 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 2971 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2972 2973 #ifdef USE_MBEDTLS_FOR_ECDH 2974 // TODO: calculate keypair using LE Random Number Generator 2975 // use test keypair from spec initially 2976 mbedtls_ecp_keypair_init(&le_keypair); 2977 mbedtls_ecp_group_load(&le_keypair.grp, MBEDTLS_ECP_DP_SECP256R1); 2978 mbedtls_mpi_read_string( &le_keypair.d, 16, "3f49f6d4a3c55f3874c9b3e3d2103f504aff607beb40b7995899b8a6cd3c1abd"); 2979 mbedtls_mpi_read_string( &le_keypair.Q.X, 16, "20b003d2f297be2c5e2c83a7e9f9a5b9eff49111acf4fddbcc0301480e359de6"); 2980 mbedtls_mpi_read_string( &le_keypair.Q.Y, 16, "dc809c49652aeb6d63329abf5a52155c766345c28fed3024741c8ed01589d28b"); 2981 mbedtls_mpi_read_string( &le_keypair.Q.Z, 16, "1"); 2982 // print keypair 2983 char buffer[100]; 2984 size_t len; 2985 mbedtls_mpi_write_string( &le_keypair.d, 16, buffer, sizeof(buffer), &len); 2986 log_info("d: %s", buffer); 2987 mbedtls_mpi_write_string( &le_keypair.Q.X, 16, buffer, sizeof(buffer), &len); 2988 log_info("X: %s", buffer); 2989 mbedtls_mpi_write_string( &le_keypair.Q.Y, 16, buffer, sizeof(buffer), &len); 2990 log_info("Y: %s", buffer); 2991 #endif 2992 } 2993 2994 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 2995 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 2996 if (!hci_con) return NULL; 2997 return &hci_con->sm_connection; 2998 } 2999 3000 // @returns 0 if not encrypted, 7-16 otherwise 3001 int sm_encryption_key_size(hci_con_handle_t con_handle){ 3002 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3003 if (!sm_conn) return 0; // wrong connection 3004 if (!sm_conn->sm_connection_encrypted) return 0; 3005 return sm_conn->sm_actual_encryption_key_size; 3006 } 3007 3008 int sm_authenticated(hci_con_handle_t con_handle){ 3009 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3010 if (!sm_conn) return 0; // wrong connection 3011 if (!sm_conn->sm_connection_encrypted) return 0; // unencrypted connection cannot be authenticated 3012 return sm_conn->sm_connection_authenticated; 3013 } 3014 3015 authorization_state_t sm_authorization_state(hci_con_handle_t con_handle){ 3016 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3017 if (!sm_conn) return AUTHORIZATION_UNKNOWN; // wrong connection 3018 if (!sm_conn->sm_connection_encrypted) return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized 3019 if (!sm_conn->sm_connection_authenticated) return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized 3020 return sm_conn->sm_connection_authorization_state; 3021 } 3022 3023 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3024 switch (sm_conn->sm_engine_state){ 3025 case SM_GENERAL_IDLE: 3026 case SM_RESPONDER_IDLE: 3027 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3028 sm_run(); 3029 break; 3030 default: 3031 break; 3032 } 3033 } 3034 3035 /** 3036 * @brief Trigger Security Request 3037 */ 3038 void sm_send_security_request(hci_con_handle_t con_handle){ 3039 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3040 if (!sm_conn) return; 3041 sm_send_security_request_for_connection(sm_conn); 3042 } 3043 3044 // request pairing 3045 void sm_request_pairing(hci_con_handle_t con_handle){ 3046 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3047 if (!sm_conn) return; // wrong connection 3048 3049 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3050 if (sm_conn->sm_role){ 3051 sm_send_security_request_for_connection(sm_conn); 3052 } else { 3053 // used as a trigger to start central/master/initiator security procedures 3054 uint16_t ediv; 3055 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3056 switch (sm_conn->sm_irk_lookup_state){ 3057 case IRK_LOOKUP_FAILED: 3058 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3059 break; 3060 case IRK_LOOKUP_SUCCEEDED: 3061 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 3062 if (ediv){ 3063 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3064 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3065 } else { 3066 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3067 } 3068 break; 3069 default: 3070 sm_conn->sm_bonding_requested = 1; 3071 break; 3072 } 3073 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3074 sm_conn->sm_bonding_requested = 1; 3075 } 3076 } 3077 sm_run(); 3078 } 3079 3080 // called by client app on authorization request 3081 void sm_authorization_decline(hci_con_handle_t con_handle){ 3082 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3083 if (!sm_conn) return; // wrong connection 3084 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3085 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3086 } 3087 3088 void sm_authorization_grant(hci_con_handle_t con_handle){ 3089 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3090 if (!sm_conn) return; // wrong connection 3091 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3092 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3093 } 3094 3095 // GAP Bonding API 3096 3097 void sm_bonding_decline(hci_con_handle_t con_handle){ 3098 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3099 if (!sm_conn) return; // wrong connection 3100 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3101 3102 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3103 sm_done_for_handle(sm_conn->sm_handle); 3104 setup->sm_pairing_failed_reason = SM_REASON_PASSKEYT_ENTRY_FAILED; 3105 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3106 } 3107 sm_run(); 3108 } 3109 3110 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3111 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3112 if (!sm_conn) return; // wrong connection 3113 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3114 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3115 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3116 3117 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3118 if (setup->sm_use_secure_connections){ 3119 sm_conn->sm_engine_state = SM_PH2_SEND_PUBLIC_KEY_COMMAND; 3120 } 3121 #endif 3122 } 3123 if (sm_conn->sm_engine_state == SM_PH2_W4_USER_RESPONSE){ 3124 if (sm_conn->sm_role){ 3125 // responder 3126 sm_conn->sm_engine_state = SM_PH2_SEND_DHKEY_CHECK_COMMAND; 3127 } else { 3128 // initiator 3129 // TODO handle intiator role 3130 } 3131 } 3132 sm_run(); 3133 } 3134 3135 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3136 // for now, it's the same 3137 sm_just_works_confirm(con_handle); 3138 } 3139 3140 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3141 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3142 if (!sm_conn) return; // wrong connection 3143 sm_reset_tk(); 3144 big_endian_store_32(setup->sm_tk, 12, passkey); 3145 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3146 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3147 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3148 } 3149 sm_run(); 3150 } 3151 3152 /** 3153 * @brief Identify device in LE Device DB 3154 * @param handle 3155 * @returns index from le_device_db or -1 if not found/identified 3156 */ 3157 int sm_le_device_index(hci_con_handle_t con_handle ){ 3158 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3159 if (!sm_conn) return -1; 3160 return sm_conn->sm_le_db_index; 3161 } 3162 3163 // GAP LE API 3164 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 3165 gap_random_address_update_stop(); 3166 gap_random_adress_type = random_address_type; 3167 if (random_address_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3168 gap_random_address_update_start(); 3169 gap_random_address_trigger(); 3170 } 3171 3172 gap_random_address_type_t gap_random_address_get_mode(void){ 3173 return gap_random_adress_type; 3174 } 3175 3176 void gap_random_address_set_update_period(int period_ms){ 3177 gap_random_adress_update_period = period_ms; 3178 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3179 gap_random_address_update_stop(); 3180 gap_random_address_update_start(); 3181 } 3182 3183 void gap_random_address_set(bd_addr_t addr){ 3184 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_OFF); 3185 memcpy(sm_random_address, addr, 6); 3186 rau_state = RAU_SET_ADDRESS; 3187 sm_run(); 3188 } 3189 3190 /* 3191 * @brief Set Advertisement Paramters 3192 * @param adv_int_min 3193 * @param adv_int_max 3194 * @param adv_type 3195 * @param direct_address_type 3196 * @param direct_address 3197 * @param channel_map 3198 * @param filter_policy 3199 * 3200 * @note own_address_type is used from gap_random_address_set_mode 3201 */ 3202 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 3203 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 3204 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, gap_random_adress_type, 3205 direct_address_typ, direct_address, channel_map, filter_policy); 3206 } 3207 3208