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_RESPONDER_PH2_W4_PUBLIC_KEY_COMMAND; 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 connection->sm_engine_state = SM_PH2_W4_CONFIRMATION; 1707 } 1708 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1709 sm_timeout_reset(connection); 1710 break; 1711 } 1712 case SM_PH2_SEND_PAIRING_RANDOM_SC: { 1713 uint8_t buffer[17]; 1714 buffer[0] = SM_CODE_PAIRING_RANDOM; 1715 reverse_128(setup->sm_local_nonce, &buffer[1]); 1716 1717 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT && setup->sm_passkey_bit < 20){ 1718 if (connection->sm_role){ 1719 // responder 1720 connection->sm_engine_state = SM_PH2_W4_CONFIRMATION; 1721 } else { 1722 // initiator 1723 connection->sm_engine_state = SM_PH2_W4_PAIRING_RANDOM; 1724 } 1725 } else { 1726 if (connection->sm_role){ 1727 // responder 1728 connection->sm_engine_state = SM_PH2_W4_DHKEY_CHECK_COMMAND; 1729 if (setup->sm_stk_generation_method == NK_BOTH_INPUT){ 1730 // calc Vb if numeric comparison 1731 // TODO: use AES Engine to calculate g2 1732 uint8_t value[32]; 1733 mbedtls_mpi_write_binary(&le_keypair.Q.X, value, sizeof(value)); 1734 uint32_t vb = g2(setup->sm_peer_qx, value, setup->sm_peer_nonce, setup->sm_local_nonce) % 1000000; 1735 big_endian_store_32(setup->sm_tk, 12, vb); 1736 sm_trigger_user_response(connection); 1737 } 1738 } else { 1739 // initiator 1740 connection->sm_engine_state = SM_PH2_W4_PAIRING_RANDOM; 1741 } 1742 } 1743 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1744 sm_timeout_reset(connection); 1745 break; 1746 } 1747 case SM_PH2_SEND_DHKEY_CHECK_COMMAND: { 1748 1749 uint8_t buffer[17]; 1750 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 1751 #ifdef USE_MBEDTLS_FOR_ECDH 1752 // calculate DHKEY 1753 mbedtls_ecp_group grp; 1754 mbedtls_ecp_group_init( &grp ); 1755 mbedtls_ecp_group_load(&grp, MBEDTLS_ECP_DP_SECP256R1); 1756 mbedtls_ecp_point Q; 1757 mbedtls_ecp_point_init( &Q ); 1758 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 1759 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 1760 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 1761 1762 // da * Pb 1763 mbedtls_ecp_point DH; 1764 mbedtls_ecp_point_init( &DH ); 1765 mbedtls_ecp_mul(&grp, &DH, &le_keypair.d, &Q, NULL, NULL); 1766 sm_key256_t dhkey; 1767 mbedtls_mpi_write_binary(&DH.X, dhkey, 32); 1768 log_info("dhkey"); 1769 log_info_hexdump(dhkey, 32); 1770 1771 // calculate LTK + MacKey 1772 sm_key256_t ltk_mackey; 1773 sm_key56_t bd_addr_master, bd_addr_slave; 1774 bd_addr_master[0] = setup->sm_m_addr_type; 1775 bd_addr_slave[0] = setup->sm_s_addr_type; 1776 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1777 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1778 if (connection->sm_role){ 1779 // responder 1780 f5(ltk_mackey, dhkey, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1781 } else { 1782 // initiator 1783 f5(ltk_mackey, dhkey, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1784 } 1785 // store LTK 1786 memcpy(setup->sm_ltk, <k_mackey[16], 16); 1787 1788 // calc DHKCheck 1789 sm_key_t mackey; 1790 memcpy(mackey, <k_mackey[0], 16); 1791 1792 // TODO: checks 1793 1794 uint8_t iocap_a[3]; 1795 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1796 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1797 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1798 uint8_t iocap_b[3]; 1799 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1800 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1801 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1802 if (connection->sm_role){ 1803 // responder 1804 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); 1805 } else { 1806 // initiator 1807 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); 1808 } 1809 #endif 1810 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 1811 if (connection->sm_role){ 1812 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST_SC; 1813 } else { 1814 connection->sm_engine_state = SM_PH2_W4_DHKEY_CHECK_COMMAND; 1815 } 1816 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1817 sm_timeout_reset(connection); 1818 break; 1819 } 1820 1821 #endif 1822 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 1823 // echo initiator for now 1824 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 1825 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1826 1827 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 1828 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1829 if (setup->sm_use_secure_connections){ 1830 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PUBLIC_KEY_COMMAND; 1831 // skip LTK/EDIV for SC 1832 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 1833 } 1834 #endif 1835 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); 1836 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); 1837 1838 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 1839 sm_timeout_reset(connection); 1840 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 1841 if (setup->sm_stk_generation_method == JUST_WORKS){ 1842 sm_trigger_user_response(connection); 1843 } 1844 return; 1845 1846 case SM_PH2_SEND_PAIRING_RANDOM: { 1847 uint8_t buffer[17]; 1848 buffer[0] = SM_CODE_PAIRING_RANDOM; 1849 reverse_128(setup->sm_local_random, &buffer[1]); 1850 if (connection->sm_role){ 1851 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 1852 } else { 1853 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 1854 } 1855 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1856 sm_timeout_reset(connection); 1857 break; 1858 } 1859 1860 case SM_PH2_GET_RANDOM_TK: 1861 case SM_PH2_C1_GET_RANDOM_A: 1862 case SM_PH2_C1_GET_RANDOM_B: 1863 case SM_PH3_GET_RANDOM: 1864 case SM_PH3_GET_DIV: 1865 sm_next_responding_state(connection); 1866 sm_random_start(connection); 1867 return; 1868 1869 case SM_PH2_C1_GET_ENC_B: 1870 case SM_PH2_C1_GET_ENC_D: 1871 // already busy? 1872 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1873 sm_next_responding_state(connection); 1874 sm_aes128_start(setup->sm_tk, setup->sm_c1_t3_value, connection); 1875 return; 1876 1877 case SM_PH3_LTK_GET_ENC: 1878 case SM_RESPONDER_PH4_LTK_GET_ENC: 1879 // already busy? 1880 if (sm_aes128_state == SM_AES128_IDLE) { 1881 sm_key_t d_prime; 1882 sm_d1_d_prime(setup->sm_local_div, 0, d_prime); 1883 sm_next_responding_state(connection); 1884 sm_aes128_start(sm_persistent_er, d_prime, connection); 1885 return; 1886 } 1887 break; 1888 1889 case SM_PH3_CSRK_GET_ENC: 1890 // already busy? 1891 if (sm_aes128_state == SM_AES128_IDLE) { 1892 sm_key_t d_prime; 1893 sm_d1_d_prime(setup->sm_local_div, 1, d_prime); 1894 sm_next_responding_state(connection); 1895 sm_aes128_start(sm_persistent_er, d_prime, connection); 1896 return; 1897 } 1898 break; 1899 1900 case SM_PH2_C1_GET_ENC_C: 1901 // already busy? 1902 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1903 // calculate m_confirm using aes128 engine - step 1 1904 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); 1905 sm_next_responding_state(connection); 1906 sm_aes128_start(setup->sm_tk, plaintext, connection); 1907 break; 1908 case SM_PH2_C1_GET_ENC_A: 1909 // already busy? 1910 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1911 // calculate confirm using aes128 engine - step 1 1912 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); 1913 sm_next_responding_state(connection); 1914 sm_aes128_start(setup->sm_tk, plaintext, connection); 1915 break; 1916 case SM_PH2_CALC_STK: 1917 // already busy? 1918 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1919 // calculate STK 1920 if (connection->sm_role){ 1921 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, plaintext); 1922 } else { 1923 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, plaintext); 1924 } 1925 sm_next_responding_state(connection); 1926 sm_aes128_start(setup->sm_tk, plaintext, connection); 1927 break; 1928 case SM_PH3_Y_GET_ENC: 1929 // already busy? 1930 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1931 // PH3B2 - calculate Y from - enc 1932 // Y = dm(DHK, Rand) 1933 sm_dm_r_prime(setup->sm_local_rand, plaintext); 1934 sm_next_responding_state(connection); 1935 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 1936 return; 1937 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 1938 uint8_t buffer[17]; 1939 buffer[0] = SM_CODE_PAIRING_CONFIRM; 1940 reverse_128(setup->sm_local_confirm, &buffer[1]); 1941 if (connection->sm_role){ 1942 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 1943 } else { 1944 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 1945 } 1946 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1947 sm_timeout_reset(connection); 1948 return; 1949 } 1950 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 1951 sm_key_t stk_flipped; 1952 reverse_128(setup->sm_ltk, stk_flipped); 1953 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 1954 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 1955 return; 1956 } 1957 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 1958 sm_key_t stk_flipped; 1959 reverse_128(setup->sm_ltk, stk_flipped); 1960 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 1961 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 1962 return; 1963 } 1964 case SM_RESPONDER_PH4_SEND_LTK: { 1965 sm_key_t ltk_flipped; 1966 reverse_128(setup->sm_ltk, ltk_flipped); 1967 connection->sm_engine_state = SM_RESPONDER_IDLE; 1968 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 1969 return; 1970 } 1971 case SM_RESPONDER_PH4_Y_GET_ENC: 1972 // already busy? 1973 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1974 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 1975 // Y = dm(DHK, Rand) 1976 sm_dm_r_prime(setup->sm_local_rand, plaintext); 1977 sm_next_responding_state(connection); 1978 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 1979 return; 1980 1981 case SM_PH3_DISTRIBUTE_KEYS: 1982 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 1983 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 1984 uint8_t buffer[17]; 1985 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 1986 reverse_128(setup->sm_ltk, &buffer[1]); 1987 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1988 sm_timeout_reset(connection); 1989 return; 1990 } 1991 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 1992 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 1993 uint8_t buffer[11]; 1994 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 1995 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 1996 reverse_64(setup->sm_local_rand, &buffer[3]); 1997 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1998 sm_timeout_reset(connection); 1999 return; 2000 } 2001 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2002 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2003 uint8_t buffer[17]; 2004 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2005 reverse_128(sm_persistent_irk, &buffer[1]); 2006 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2007 sm_timeout_reset(connection); 2008 return; 2009 } 2010 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2011 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2012 bd_addr_t local_address; 2013 uint8_t buffer[8]; 2014 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2015 gap_advertisements_get_address(&buffer[1], local_address); 2016 reverse_bd_addr(local_address, &buffer[2]); 2017 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2018 sm_timeout_reset(connection); 2019 return; 2020 } 2021 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2022 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2023 2024 // hack to reproduce test runs 2025 if (test_use_fixed_local_csrk){ 2026 memset(setup->sm_local_csrk, 0xcc, 16); 2027 } 2028 2029 uint8_t buffer[17]; 2030 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2031 reverse_128(setup->sm_local_csrk, &buffer[1]); 2032 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2033 sm_timeout_reset(connection); 2034 return; 2035 } 2036 2037 // keys are sent 2038 if (connection->sm_role){ 2039 // slave -> receive master keys if any 2040 if (sm_key_distribution_all_received(connection)){ 2041 sm_key_distribution_handle_all_received(connection); 2042 connection->sm_engine_state = SM_RESPONDER_IDLE; 2043 sm_done_for_handle(connection->sm_handle); 2044 } else { 2045 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2046 } 2047 } else { 2048 // master -> all done 2049 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2050 sm_done_for_handle(connection->sm_handle); 2051 } 2052 break; 2053 2054 default: 2055 break; 2056 } 2057 2058 // check again if active connection was released 2059 if (sm_active_connection) break; 2060 } 2061 } 2062 2063 // note: aes engine is ready as we just got the aes result 2064 static void sm_handle_encryption_result(uint8_t * data){ 2065 2066 sm_aes128_state = SM_AES128_IDLE; 2067 2068 if (sm_address_resolution_ah_calculation_active){ 2069 sm_address_resolution_ah_calculation_active = 0; 2070 // compare calulated address against connecting device 2071 uint8_t hash[3]; 2072 reverse_24(data, hash); 2073 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2074 log_info("LE Device Lookup: matched resolvable private address"); 2075 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2076 return; 2077 } 2078 // no match, try next 2079 sm_address_resolution_test++; 2080 return; 2081 } 2082 2083 switch (dkg_state){ 2084 case DKG_W4_IRK: 2085 reverse_128(data, sm_persistent_irk); 2086 log_info_key("irk", sm_persistent_irk); 2087 dkg_next_state(); 2088 return; 2089 case DKG_W4_DHK: 2090 reverse_128(data, sm_persistent_dhk); 2091 log_info_key("dhk", sm_persistent_dhk); 2092 dkg_next_state(); 2093 // SM Init Finished 2094 return; 2095 default: 2096 break; 2097 } 2098 2099 switch (rau_state){ 2100 case RAU_W4_ENC: 2101 reverse_24(data, &sm_random_address[3]); 2102 rau_next_state(); 2103 return; 2104 default: 2105 break; 2106 } 2107 2108 switch (sm_cmac_state){ 2109 case CMAC_W4_SUBKEYS: 2110 case CMAC_W4_MI: 2111 case CMAC_W4_MLAST: 2112 { 2113 sm_key_t t; 2114 reverse_128(data, t); 2115 sm_cmac_handle_encryption_result(t); 2116 } 2117 return; 2118 default: 2119 break; 2120 } 2121 2122 // retrieve sm_connection provided to sm_aes128_start_encryption 2123 sm_connection_t * connection = (sm_connection_t*) sm_aes128_context; 2124 if (!connection) return; 2125 switch (connection->sm_engine_state){ 2126 case SM_PH2_C1_W4_ENC_A: 2127 case SM_PH2_C1_W4_ENC_C: 2128 { 2129 sm_key_t t2; 2130 reverse_128(data, t2); 2131 sm_c1_t3(t2, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2132 } 2133 sm_next_responding_state(connection); 2134 return; 2135 case SM_PH2_C1_W4_ENC_B: 2136 reverse_128(data, setup->sm_local_confirm); 2137 log_info_key("c1!", setup->sm_local_confirm); 2138 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2139 return; 2140 case SM_PH2_C1_W4_ENC_D: 2141 { 2142 sm_key_t peer_confirm_test; 2143 reverse_128(data, peer_confirm_test); 2144 log_info_key("c1!", peer_confirm_test); 2145 if (memcmp(setup->sm_peer_confirm, peer_confirm_test, 16) != 0){ 2146 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2147 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2148 return; 2149 } 2150 if (connection->sm_role){ 2151 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2152 } else { 2153 connection->sm_engine_state = SM_PH2_CALC_STK; 2154 } 2155 } 2156 return; 2157 case SM_PH2_W4_STK: 2158 reverse_128(data, setup->sm_ltk); 2159 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2160 log_info_key("stk", setup->sm_ltk); 2161 if (connection->sm_role){ 2162 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2163 } else { 2164 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2165 } 2166 return; 2167 case SM_PH3_Y_W4_ENC:{ 2168 sm_key_t y128; 2169 reverse_128(data, y128); 2170 setup->sm_local_y = big_endian_read_16(y128, 14); 2171 log_info_hex16("y", setup->sm_local_y); 2172 // PH3B3 - calculate EDIV 2173 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2174 log_info_hex16("ediv", setup->sm_local_ediv); 2175 // PH3B4 - calculate LTK - enc 2176 // LTK = d1(ER, DIV, 0)) 2177 connection->sm_engine_state = SM_PH3_LTK_GET_ENC; 2178 return; 2179 } 2180 case SM_RESPONDER_PH4_Y_W4_ENC:{ 2181 sm_key_t y128; 2182 reverse_128(data, y128); 2183 setup->sm_local_y = big_endian_read_16(y128, 14); 2184 log_info_hex16("y", setup->sm_local_y); 2185 2186 // PH3B3 - calculate DIV 2187 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2188 log_info_hex16("ediv", setup->sm_local_ediv); 2189 // PH3B4 - calculate LTK - enc 2190 // LTK = d1(ER, DIV, 0)) 2191 connection->sm_engine_state = SM_RESPONDER_PH4_LTK_GET_ENC; 2192 return; 2193 } 2194 case SM_PH3_LTK_W4_ENC: 2195 reverse_128(data, setup->sm_ltk); 2196 log_info_key("ltk", setup->sm_ltk); 2197 // calc CSRK next 2198 connection->sm_engine_state = SM_PH3_CSRK_GET_ENC; 2199 return; 2200 case SM_PH3_CSRK_W4_ENC: 2201 reverse_128(data, setup->sm_local_csrk); 2202 log_info_key("csrk", setup->sm_local_csrk); 2203 if (setup->sm_key_distribution_send_set){ 2204 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2205 } else { 2206 // no keys to send, just continue 2207 if (connection->sm_role){ 2208 // slave -> receive master keys 2209 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2210 } else { 2211 // master -> all done 2212 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2213 sm_done_for_handle(connection->sm_handle); 2214 } 2215 } 2216 return; 2217 case SM_RESPONDER_PH4_LTK_W4_ENC: 2218 reverse_128(data, setup->sm_ltk); 2219 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2220 log_info_key("ltk", setup->sm_ltk); 2221 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK; 2222 return; 2223 default: 2224 break; 2225 } 2226 } 2227 2228 // note: random generator is ready. this doesn NOT imply that aes engine is unused! 2229 static void sm_handle_random_result(uint8_t * data){ 2230 2231 switch (rau_state){ 2232 case RAU_W4_RANDOM: 2233 // non-resolvable vs. resolvable 2234 switch (gap_random_adress_type){ 2235 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2236 // resolvable: use random as prand and calc address hash 2237 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2238 memcpy(sm_random_address, data, 3); 2239 sm_random_address[0] &= 0x3f; 2240 sm_random_address[0] |= 0x40; 2241 rau_state = RAU_GET_ENC; 2242 break; 2243 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2244 default: 2245 // "The two most significant bits of the address shall be equal to ‘0’"" 2246 memcpy(sm_random_address, data, 6); 2247 sm_random_address[0] &= 0x3f; 2248 rau_state = RAU_SET_ADDRESS; 2249 break; 2250 } 2251 return; 2252 default: 2253 break; 2254 } 2255 2256 // retrieve sm_connection provided to sm_random_start 2257 sm_connection_t * connection = (sm_connection_t *) sm_random_context; 2258 if (!connection) return; 2259 switch (connection->sm_engine_state){ 2260 case SM_PH2_W4_RANDOM_TK: 2261 { 2262 // map random to 0-999999 without speding much cycles on a modulus operation 2263 uint32_t tk = little_endian_read_32(data,0); 2264 tk = tk & 0xfffff; // 1048575 2265 if (tk >= 999999){ 2266 tk = tk - 999999; 2267 } 2268 sm_reset_tk(); 2269 big_endian_store_32(setup->sm_tk, 12, tk); 2270 if (connection->sm_role){ 2271 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2272 } else { 2273 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2274 sm_trigger_user_response(connection); 2275 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2276 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2277 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 2278 } 2279 } 2280 return; 2281 } 2282 case SM_PH2_C1_W4_RANDOM_A: 2283 memcpy(&setup->sm_local_random[0], data, 8); // random endinaness 2284 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_B; 2285 return; 2286 case SM_PH2_C1_W4_RANDOM_B: 2287 memcpy(&setup->sm_local_random[8], data, 8); // random endinaness 2288 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2289 return; 2290 case SM_PH3_W4_RANDOM: 2291 reverse_64(data, setup->sm_local_rand); 2292 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2293 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2294 // no db for authenticated flag hack: store flag in bit 4 of LSB 2295 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2296 connection->sm_engine_state = SM_PH3_GET_DIV; 2297 return; 2298 case SM_PH3_W4_DIV: 2299 // use 16 bit from random value as div 2300 setup->sm_local_div = big_endian_read_16(data, 0); 2301 log_info_hex16("div", setup->sm_local_div); 2302 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2303 return; 2304 default: 2305 break; 2306 } 2307 } 2308 2309 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2310 2311 sm_connection_t * sm_conn; 2312 hci_con_handle_t con_handle; 2313 2314 switch (packet_type) { 2315 2316 case HCI_EVENT_PACKET: 2317 switch (hci_event_packet_get_type(packet)) { 2318 2319 case BTSTACK_EVENT_STATE: 2320 // bt stack activated, get started 2321 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2322 log_info("HCI Working!"); 2323 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 2324 rau_state = RAU_IDLE; 2325 sm_run(); 2326 } 2327 break; 2328 2329 case HCI_EVENT_LE_META: 2330 switch (packet[2]) { 2331 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2332 2333 log_info("sm: connected"); 2334 2335 if (packet[3]) return; // connection failed 2336 2337 con_handle = little_endian_read_16(packet, 4); 2338 sm_conn = sm_get_connection_for_handle(con_handle); 2339 if (!sm_conn) break; 2340 2341 sm_conn->sm_handle = con_handle; 2342 sm_conn->sm_role = packet[6]; 2343 sm_conn->sm_peer_addr_type = packet[7]; 2344 reverse_bd_addr(&packet[8], 2345 sm_conn->sm_peer_address); 2346 2347 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2348 2349 // reset security properties 2350 sm_conn->sm_connection_encrypted = 0; 2351 sm_conn->sm_connection_authenticated = 0; 2352 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2353 sm_conn->sm_le_db_index = -1; 2354 2355 // prepare CSRK lookup (does not involve setup) 2356 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2357 2358 // just connected -> everything else happens in sm_run() 2359 if (sm_conn->sm_role){ 2360 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2361 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2362 if (sm_slave_request_security) { 2363 // request security if requested by app 2364 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2365 } else { 2366 // otherwise, wait for pairing request 2367 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2368 } 2369 } 2370 break; 2371 } else { 2372 // master 2373 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2374 } 2375 break; 2376 2377 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2378 con_handle = little_endian_read_16(packet, 3); 2379 sm_conn = sm_get_connection_for_handle(con_handle); 2380 if (!sm_conn) break; 2381 2382 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2383 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2384 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2385 break; 2386 } 2387 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST_SC){ 2388 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2389 break; 2390 } 2391 2392 // assume that we don't have a LTK for ediv == 0 and random == null 2393 if (little_endian_read_16(packet, 13) == 0 && sm_is_null_random(&packet[5])){ 2394 log_info("LTK Request: ediv & random are empty"); 2395 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 2396 break; 2397 } 2398 2399 // store rand and ediv 2400 reverse_64(&packet[5], sm_conn->sm_local_rand); 2401 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2402 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK; 2403 break; 2404 2405 default: 2406 break; 2407 } 2408 break; 2409 2410 case HCI_EVENT_ENCRYPTION_CHANGE: 2411 con_handle = little_endian_read_16(packet, 3); 2412 sm_conn = sm_get_connection_for_handle(con_handle); 2413 if (!sm_conn) break; 2414 2415 sm_conn->sm_connection_encrypted = packet[5]; 2416 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 2417 sm_conn->sm_actual_encryption_key_size); 2418 log_info("event handler, state %u", sm_conn->sm_engine_state); 2419 if (!sm_conn->sm_connection_encrypted) break; 2420 // continue if part of initial pairing 2421 switch (sm_conn->sm_engine_state){ 2422 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2423 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2424 sm_done_for_handle(sm_conn->sm_handle); 2425 break; 2426 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2427 if (sm_conn->sm_role){ 2428 // slave 2429 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2430 } else { 2431 // master 2432 if (sm_key_distribution_all_received(sm_conn)){ 2433 // skip receiving keys as there are none 2434 sm_key_distribution_handle_all_received(sm_conn); 2435 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2436 } else { 2437 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2438 } 2439 } 2440 break; 2441 default: 2442 break; 2443 } 2444 break; 2445 2446 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 2447 con_handle = little_endian_read_16(packet, 3); 2448 sm_conn = sm_get_connection_for_handle(con_handle); 2449 if (!sm_conn) break; 2450 2451 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 2452 log_info("event handler, state %u", sm_conn->sm_engine_state); 2453 // continue if part of initial pairing 2454 switch (sm_conn->sm_engine_state){ 2455 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2456 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2457 sm_done_for_handle(sm_conn->sm_handle); 2458 break; 2459 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2460 if (sm_conn->sm_role){ 2461 // slave 2462 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2463 } else { 2464 // master 2465 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2466 } 2467 break; 2468 default: 2469 break; 2470 } 2471 break; 2472 2473 2474 case HCI_EVENT_DISCONNECTION_COMPLETE: 2475 con_handle = little_endian_read_16(packet, 3); 2476 sm_done_for_handle(con_handle); 2477 sm_conn = sm_get_connection_for_handle(con_handle); 2478 if (!sm_conn) break; 2479 2480 // delete stored bonding on disconnect with authentication failure in ph0 2481 if (sm_conn->sm_role == 0 2482 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 2483 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 2484 le_device_db_remove(sm_conn->sm_le_db_index); 2485 } 2486 2487 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 2488 sm_conn->sm_handle = 0; 2489 break; 2490 2491 case HCI_EVENT_COMMAND_COMPLETE: 2492 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 2493 sm_handle_encryption_result(&packet[6]); 2494 break; 2495 } 2496 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 2497 sm_handle_random_result(&packet[6]); 2498 break; 2499 } 2500 break; 2501 default: 2502 break; 2503 } 2504 break; 2505 default: 2506 break; 2507 } 2508 2509 sm_run(); 2510 } 2511 2512 static inline int sm_calc_actual_encryption_key_size(int other){ 2513 if (other < sm_min_encryption_key_size) return 0; 2514 if (other < sm_max_encryption_key_size) return other; 2515 return sm_max_encryption_key_size; 2516 } 2517 2518 /** 2519 * @return ok 2520 */ 2521 static int sm_validate_stk_generation_method(void){ 2522 // check if STK generation method is acceptable by client 2523 switch (setup->sm_stk_generation_method){ 2524 case JUST_WORKS: 2525 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 2526 case PK_RESP_INPUT: 2527 case PK_INIT_INPUT: 2528 case OK_BOTH_INPUT: 2529 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 2530 case OOB: 2531 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 2532 case NK_BOTH_INPUT: 2533 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 2534 return 1; 2535 default: 2536 return 0; 2537 } 2538 } 2539 2540 // helper for sm_pdu_handler, calls sm_run on exit 2541 static void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 2542 setup->sm_pairing_failed_reason = SM_REASON_UNSPECIFIED_REASON; 2543 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2544 sm_done_for_handle(sm_conn->sm_handle); 2545 } 2546 2547 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 2548 2549 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 2550 sm_run(); 2551 } 2552 2553 if (packet_type != SM_DATA_PACKET) return; 2554 2555 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 2556 if (!sm_conn) return; 2557 2558 if (packet[0] == SM_CODE_PAIRING_FAILED){ 2559 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2560 return; 2561 } 2562 2563 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, packet[0]); 2564 2565 int err; 2566 2567 switch (sm_conn->sm_engine_state){ 2568 2569 // a sm timeout requries a new physical connection 2570 case SM_GENERAL_TIMEOUT: 2571 return; 2572 2573 // Initiator 2574 case SM_INITIATOR_CONNECTED: 2575 if ((packet[0] != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 2576 sm_pdu_received_in_wrong_state(sm_conn); 2577 break; 2578 } 2579 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 2580 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 2581 break; 2582 } 2583 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 2584 uint16_t ediv; 2585 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 2586 if (ediv){ 2587 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 2588 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 2589 } else { 2590 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 2591 } 2592 break; 2593 } 2594 // otherwise, store security request 2595 sm_conn->sm_security_request_received = 1; 2596 break; 2597 2598 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 2599 if (packet[0] != SM_CODE_PAIRING_RESPONSE){ 2600 sm_pdu_received_in_wrong_state(sm_conn); 2601 break; 2602 } 2603 // store pairing request 2604 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 2605 err = sm_stk_generation_init(sm_conn); 2606 if (err){ 2607 setup->sm_pairing_failed_reason = err; 2608 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2609 break; 2610 } 2611 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2612 if (setup->sm_use_secure_connections){ 2613 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2614 if (setup->sm_stk_generation_method == JUST_WORKS){ 2615 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2616 sm_trigger_user_response(sm_conn); 2617 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2618 sm_conn->sm_engine_state = SM_PH2_SEND_PUBLIC_KEY_COMMAND; 2619 } 2620 } else { 2621 sm_conn->sm_engine_state = SM_PH2_SEND_PUBLIC_KEY_COMMAND; 2622 } 2623 break; 2624 } 2625 #endif 2626 // generate random number first, if we need to show passkey 2627 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 2628 sm_conn->sm_engine_state = SM_PH2_GET_RANDOM_TK; 2629 break; 2630 } 2631 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2632 sm_trigger_user_response(sm_conn); 2633 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2634 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2635 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 2636 } 2637 break; 2638 2639 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 2640 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 2641 sm_pdu_received_in_wrong_state(sm_conn); 2642 break; 2643 } 2644 2645 // store s_confirm 2646 reverse_128(&packet[1], setup->sm_peer_confirm); 2647 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2648 break; 2649 2650 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 2651 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 2652 sm_pdu_received_in_wrong_state(sm_conn); 2653 break;; 2654 } 2655 2656 // received random value 2657 reverse_128(&packet[1], setup->sm_peer_random); 2658 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 2659 break; 2660 2661 // Responder 2662 case SM_RESPONDER_IDLE: 2663 case SM_RESPONDER_SEND_SECURITY_REQUEST: 2664 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 2665 if (packet[0] != SM_CODE_PAIRING_REQUEST){ 2666 sm_pdu_received_in_wrong_state(sm_conn); 2667 break;; 2668 } 2669 2670 // store pairing request 2671 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 2672 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 2673 break; 2674 2675 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2676 case SM_RESPONDER_PH2_W4_PUBLIC_KEY_COMMAND: 2677 if (packet[0] != SM_CODE_PAIRING_PUBLIC_KEY){ 2678 sm_pdu_received_in_wrong_state(sm_conn); 2679 break; 2680 } 2681 2682 // store public key for DH Key calculation 2683 reverse_256(&packet[01], setup->sm_peer_qx); 2684 reverse_256(&packet[33], setup->sm_peer_qy); 2685 2686 #ifdef USE_MBEDTLS_FOR_ECDH 2687 // validate public key 2688 mbedtls_ecp_group grp; 2689 mbedtls_ecp_group_init( &grp ); 2690 mbedtls_ecp_group_load(&grp, MBEDTLS_ECP_DP_SECP256R1); 2691 2692 mbedtls_ecp_point Q; 2693 mbedtls_ecp_point_init( &Q ); 2694 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 2695 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 2696 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 2697 err = mbedtls_ecp_check_pubkey(&grp, &Q); 2698 if (err){ 2699 log_error("sm: peer public key invalid %x", err); 2700 // uses "unspecified reason", there is no "public key invalid" error code 2701 sm_pdu_received_in_wrong_state(sm_conn); 2702 break; 2703 } 2704 #endif 2705 if (sm_conn->sm_role){ 2706 // responder 2707 sm_conn->sm_engine_state = SM_PH2_SEND_PUBLIC_KEY_COMMAND; 2708 } else { 2709 // initiator 2710 // stk generation method 2711 // passkey entry: notify app to show passkey or to request passkey 2712 switch (setup->sm_stk_generation_method){ 2713 case JUST_WORKS: 2714 case NK_BOTH_INPUT: 2715 sm_conn->sm_engine_state = SM_PH2_W4_CONFIRMATION; 2716 break; 2717 case PK_INIT_INPUT: 2718 case PK_RESP_INPUT: 2719 case OK_BOTH_INPUT: 2720 sm_conn->sm_engine_state = SM_PH2_SEND_CONFIRMATION; 2721 break; 2722 case OOB: 2723 // TODO: implement SC OOB 2724 break; 2725 } 2726 } 2727 break; 2728 2729 case SM_PH2_W4_CONFIRMATION: 2730 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 2731 sm_pdu_received_in_wrong_state(sm_conn); 2732 break; 2733 } 2734 // received confirm value 2735 reverse_128(&packet[1], setup->sm_peer_confirm); 2736 2737 if (sm_conn->sm_role){ 2738 // responder 2739 sm_conn->sm_engine_state = SM_PH2_SEND_CONFIRMATION; 2740 } else { 2741 // initiator 2742 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM_SC; 2743 } 2744 break; 2745 2746 case SM_PH2_W4_PAIRING_RANDOM: 2747 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 2748 sm_pdu_received_in_wrong_state(sm_conn); 2749 break; 2750 } 2751 2752 // received random value 2753 reverse_128(&packet[1], setup->sm_peer_nonce); 2754 2755 if (sm_conn->sm_role){ 2756 // Responder 2757 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM_SC; 2758 } else { 2759 // Initiator role 2760 2761 // TODO: validate confirmation values 2762 2763 switch (setup->sm_stk_generation_method){ 2764 case JUST_WORKS: 2765 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2766 break; 2767 2768 case NK_BOTH_INPUT: { 2769 // TODO: check if Cb = f4(Pkb, Pka, Nb, 0) 2770 2771 // calc Va if numeric comparison 2772 // TODO: use AES Engine to calculate g2 2773 uint8_t value[32]; 2774 mbedtls_mpi_write_binary(&le_keypair.Q.X, value, sizeof(value)); 2775 uint32_t va = g2(value, setup->sm_peer_qx, setup->sm_local_nonce, setup->sm_peer_nonce) % 1000000; 2776 big_endian_store_32(setup->sm_tk, 12, va); 2777 sm_trigger_user_response(sm_conn); 2778 break; 2779 } 2780 case PK_INIT_INPUT: 2781 case PK_RESP_INPUT: 2782 case OK_BOTH_INPUT: 2783 if (setup->sm_passkey_bit < 20) { 2784 sm_conn->sm_engine_state = SM_PH2_SEND_CONFIRMATION; 2785 } else { 2786 sm_conn->sm_engine_state = SM_PH2_SEND_DHKEY_CHECK_COMMAND; 2787 } 2788 break; 2789 case OOB: 2790 // TODO: implement SC OOB 2791 break; 2792 } 2793 } 2794 break; 2795 2796 case SM_PH2_W4_DHKEY_CHECK_COMMAND: 2797 if (packet[0] != SM_CODE_PAIRING_DHKEY_CHECK){ 2798 sm_pdu_received_in_wrong_state(sm_conn); 2799 break; 2800 } 2801 // store DHKey Check 2802 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 2803 2804 // TODO: validate DHKey Check value 2805 2806 if (sm_conn->sm_role){ 2807 // responder 2808 // for numeric comparison, we need to wait for user confirm 2809 if (setup->sm_stk_generation_method == NK_BOTH_INPUT && setup->sm_user_response != SM_USER_RESPONSE_CONFIRM){ 2810 sm_conn->sm_engine_state = SM_PH2_W4_USER_RESPONSE; 2811 } else { 2812 sm_conn->sm_engine_state = SM_PH2_SEND_DHKEY_CHECK_COMMAND; 2813 } 2814 } else { 2815 // initiator 2816 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2817 } 2818 break; 2819 #endif 2820 2821 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 2822 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 2823 sm_pdu_received_in_wrong_state(sm_conn); 2824 break; 2825 } 2826 2827 // received confirm value 2828 reverse_128(&packet[1], setup->sm_peer_confirm); 2829 2830 // notify client to hide shown passkey 2831 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 2832 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 2833 } 2834 2835 // handle user cancel pairing? 2836 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 2837 setup->sm_pairing_failed_reason = SM_REASON_PASSKEYT_ENTRY_FAILED; 2838 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2839 break; 2840 } 2841 2842 // wait for user action? 2843 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 2844 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2845 break; 2846 } 2847 2848 // calculate and send local_confirm 2849 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 2850 break; 2851 2852 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 2853 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 2854 sm_pdu_received_in_wrong_state(sm_conn); 2855 break;; 2856 } 2857 2858 // received random value 2859 reverse_128(&packet[1], setup->sm_peer_random); 2860 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 2861 break; 2862 2863 case SM_PH3_RECEIVE_KEYS: 2864 switch(packet[0]){ 2865 case SM_CODE_ENCRYPTION_INFORMATION: 2866 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2867 reverse_128(&packet[1], setup->sm_peer_ltk); 2868 break; 2869 2870 case SM_CODE_MASTER_IDENTIFICATION: 2871 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2872 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 2873 reverse_64(&packet[3], setup->sm_peer_rand); 2874 break; 2875 2876 case SM_CODE_IDENTITY_INFORMATION: 2877 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2878 reverse_128(&packet[1], setup->sm_peer_irk); 2879 break; 2880 2881 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 2882 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2883 setup->sm_peer_addr_type = packet[1]; 2884 reverse_bd_addr(&packet[2], setup->sm_peer_address); 2885 break; 2886 2887 case SM_CODE_SIGNING_INFORMATION: 2888 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2889 reverse_128(&packet[1], setup->sm_peer_csrk); 2890 break; 2891 default: 2892 // Unexpected PDU 2893 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 2894 break; 2895 } 2896 // done with key distribution? 2897 if (sm_key_distribution_all_received(sm_conn)){ 2898 2899 sm_key_distribution_handle_all_received(sm_conn); 2900 2901 if (sm_conn->sm_role){ 2902 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2903 sm_done_for_handle(sm_conn->sm_handle); 2904 } else { 2905 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2906 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2907 if (setup->sm_use_secure_connections){ 2908 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2909 } 2910 #endif 2911 } 2912 } 2913 break; 2914 default: 2915 // Unexpected PDU 2916 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 2917 break; 2918 } 2919 2920 // try to send preparared packet 2921 sm_run(); 2922 } 2923 2924 // Security Manager Client API 2925 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data)){ 2926 sm_get_oob_data = get_oob_data_callback; 2927 } 2928 2929 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 2930 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 2931 } 2932 2933 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 2934 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 2935 } 2936 2937 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 2938 sm_min_encryption_key_size = min_size; 2939 sm_max_encryption_key_size = max_size; 2940 } 2941 2942 void sm_set_authentication_requirements(uint8_t auth_req){ 2943 sm_auth_req = auth_req; 2944 } 2945 2946 void sm_set_io_capabilities(io_capability_t io_capability){ 2947 sm_io_capabilities = io_capability; 2948 } 2949 2950 void sm_set_request_security(int enable){ 2951 sm_slave_request_security = enable; 2952 } 2953 2954 void sm_set_er(sm_key_t er){ 2955 memcpy(sm_persistent_er, er, 16); 2956 } 2957 2958 void sm_set_ir(sm_key_t ir){ 2959 memcpy(sm_persistent_ir, ir, 16); 2960 } 2961 2962 // Testing support only 2963 void sm_test_set_irk(sm_key_t irk){ 2964 memcpy(sm_persistent_irk, irk, 16); 2965 sm_persistent_irk_ready = 1; 2966 } 2967 2968 void sm_test_use_fixed_local_csrk(void){ 2969 test_use_fixed_local_csrk = 1; 2970 } 2971 2972 void sm_init(void){ 2973 // set some (BTstack default) ER and IR 2974 int i; 2975 sm_key_t er; 2976 sm_key_t ir; 2977 for (i=0;i<16;i++){ 2978 er[i] = 0x30 + i; 2979 ir[i] = 0x90 + i; 2980 } 2981 sm_set_er(er); 2982 sm_set_ir(ir); 2983 // defaults 2984 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 2985 | SM_STK_GENERATION_METHOD_OOB 2986 | SM_STK_GENERATION_METHOD_PASSKEY 2987 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 2988 2989 sm_max_encryption_key_size = 16; 2990 sm_min_encryption_key_size = 7; 2991 2992 sm_cmac_state = CMAC_IDLE; 2993 dkg_state = DKG_W4_WORKING; 2994 rau_state = RAU_W4_WORKING; 2995 sm_aes128_state = SM_AES128_IDLE; 2996 sm_address_resolution_test = -1; // no private address to resolve yet 2997 sm_address_resolution_ah_calculation_active = 0; 2998 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 2999 sm_address_resolution_general_queue = NULL; 3000 3001 gap_random_adress_update_period = 15 * 60 * 1000L; 3002 3003 sm_active_connection = 0; 3004 3005 test_use_fixed_local_csrk = 0; 3006 3007 // register for HCI Events from HCI 3008 hci_event_callback_registration.callback = &sm_event_packet_handler; 3009 hci_add_event_handler(&hci_event_callback_registration); 3010 3011 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3012 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3013 3014 #ifdef USE_MBEDTLS_FOR_ECDH 3015 // TODO: calculate keypair using LE Random Number Generator 3016 // use test keypair from spec initially 3017 mbedtls_ecp_keypair_init(&le_keypair); 3018 mbedtls_ecp_group_load(&le_keypair.grp, MBEDTLS_ECP_DP_SECP256R1); 3019 mbedtls_mpi_read_string( &le_keypair.d, 16, "3f49f6d4a3c55f3874c9b3e3d2103f504aff607beb40b7995899b8a6cd3c1abd"); 3020 mbedtls_mpi_read_string( &le_keypair.Q.X, 16, "20b003d2f297be2c5e2c83a7e9f9a5b9eff49111acf4fddbcc0301480e359de6"); 3021 mbedtls_mpi_read_string( &le_keypair.Q.Y, 16, "dc809c49652aeb6d63329abf5a52155c766345c28fed3024741c8ed01589d28b"); 3022 mbedtls_mpi_read_string( &le_keypair.Q.Z, 16, "1"); 3023 // print keypair 3024 char buffer[100]; 3025 size_t len; 3026 mbedtls_mpi_write_string( &le_keypair.d, 16, buffer, sizeof(buffer), &len); 3027 log_info("d: %s", buffer); 3028 mbedtls_mpi_write_string( &le_keypair.Q.X, 16, buffer, sizeof(buffer), &len); 3029 log_info("X: %s", buffer); 3030 mbedtls_mpi_write_string( &le_keypair.Q.Y, 16, buffer, sizeof(buffer), &len); 3031 log_info("Y: %s", buffer); 3032 #endif 3033 } 3034 3035 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3036 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3037 if (!hci_con) return NULL; 3038 return &hci_con->sm_connection; 3039 } 3040 3041 // @returns 0 if not encrypted, 7-16 otherwise 3042 int sm_encryption_key_size(hci_con_handle_t con_handle){ 3043 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3044 if (!sm_conn) return 0; // wrong connection 3045 if (!sm_conn->sm_connection_encrypted) return 0; 3046 return sm_conn->sm_actual_encryption_key_size; 3047 } 3048 3049 int sm_authenticated(hci_con_handle_t con_handle){ 3050 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3051 if (!sm_conn) return 0; // wrong connection 3052 if (!sm_conn->sm_connection_encrypted) return 0; // unencrypted connection cannot be authenticated 3053 return sm_conn->sm_connection_authenticated; 3054 } 3055 3056 authorization_state_t sm_authorization_state(hci_con_handle_t con_handle){ 3057 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3058 if (!sm_conn) return AUTHORIZATION_UNKNOWN; // wrong connection 3059 if (!sm_conn->sm_connection_encrypted) return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized 3060 if (!sm_conn->sm_connection_authenticated) return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized 3061 return sm_conn->sm_connection_authorization_state; 3062 } 3063 3064 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3065 switch (sm_conn->sm_engine_state){ 3066 case SM_GENERAL_IDLE: 3067 case SM_RESPONDER_IDLE: 3068 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3069 sm_run(); 3070 break; 3071 default: 3072 break; 3073 } 3074 } 3075 3076 /** 3077 * @brief Trigger Security Request 3078 */ 3079 void sm_send_security_request(hci_con_handle_t con_handle){ 3080 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3081 if (!sm_conn) return; 3082 sm_send_security_request_for_connection(sm_conn); 3083 } 3084 3085 // request pairing 3086 void sm_request_pairing(hci_con_handle_t con_handle){ 3087 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3088 if (!sm_conn) return; // wrong connection 3089 3090 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3091 if (sm_conn->sm_role){ 3092 sm_send_security_request_for_connection(sm_conn); 3093 } else { 3094 // used as a trigger to start central/master/initiator security procedures 3095 uint16_t ediv; 3096 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3097 switch (sm_conn->sm_irk_lookup_state){ 3098 case IRK_LOOKUP_FAILED: 3099 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3100 break; 3101 case IRK_LOOKUP_SUCCEEDED: 3102 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 3103 if (ediv){ 3104 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3105 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3106 } else { 3107 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3108 } 3109 break; 3110 default: 3111 sm_conn->sm_bonding_requested = 1; 3112 break; 3113 } 3114 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3115 sm_conn->sm_bonding_requested = 1; 3116 } 3117 } 3118 sm_run(); 3119 } 3120 3121 // called by client app on authorization request 3122 void sm_authorization_decline(hci_con_handle_t con_handle){ 3123 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3124 if (!sm_conn) return; // wrong connection 3125 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3126 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3127 } 3128 3129 void sm_authorization_grant(hci_con_handle_t con_handle){ 3130 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3131 if (!sm_conn) return; // wrong connection 3132 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3133 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3134 } 3135 3136 // GAP Bonding API 3137 3138 void sm_bonding_decline(hci_con_handle_t con_handle){ 3139 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3140 if (!sm_conn) return; // wrong connection 3141 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3142 3143 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3144 sm_done_for_handle(sm_conn->sm_handle); 3145 setup->sm_pairing_failed_reason = SM_REASON_PASSKEYT_ENTRY_FAILED; 3146 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3147 } 3148 sm_run(); 3149 } 3150 3151 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3152 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3153 if (!sm_conn) return; // wrong connection 3154 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3155 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3156 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3157 3158 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3159 if (setup->sm_use_secure_connections){ 3160 sm_conn->sm_engine_state = SM_PH2_SEND_PUBLIC_KEY_COMMAND; 3161 } 3162 #endif 3163 } 3164 if (sm_conn->sm_engine_state == SM_PH2_W4_USER_RESPONSE){ 3165 if (sm_conn->sm_role){ 3166 // responder 3167 sm_conn->sm_engine_state = SM_PH2_SEND_DHKEY_CHECK_COMMAND; 3168 } else { 3169 // initiator 3170 // TODO handle intiator role 3171 } 3172 } 3173 sm_run(); 3174 } 3175 3176 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3177 // for now, it's the same 3178 sm_just_works_confirm(con_handle); 3179 } 3180 3181 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3182 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3183 if (!sm_conn) return; // wrong connection 3184 sm_reset_tk(); 3185 big_endian_store_32(setup->sm_tk, 12, passkey); 3186 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3187 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3188 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3189 } 3190 sm_run(); 3191 } 3192 3193 /** 3194 * @brief Identify device in LE Device DB 3195 * @param handle 3196 * @returns index from le_device_db or -1 if not found/identified 3197 */ 3198 int sm_le_device_index(hci_con_handle_t con_handle ){ 3199 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3200 if (!sm_conn) return -1; 3201 return sm_conn->sm_le_db_index; 3202 } 3203 3204 // GAP LE API 3205 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 3206 gap_random_address_update_stop(); 3207 gap_random_adress_type = random_address_type; 3208 if (random_address_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3209 gap_random_address_update_start(); 3210 gap_random_address_trigger(); 3211 } 3212 3213 gap_random_address_type_t gap_random_address_get_mode(void){ 3214 return gap_random_adress_type; 3215 } 3216 3217 void gap_random_address_set_update_period(int period_ms){ 3218 gap_random_adress_update_period = period_ms; 3219 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3220 gap_random_address_update_stop(); 3221 gap_random_address_update_start(); 3222 } 3223 3224 void gap_random_address_set(bd_addr_t addr){ 3225 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_OFF); 3226 memcpy(sm_random_address, addr, 6); 3227 rau_state = RAU_SET_ADDRESS; 3228 sm_run(); 3229 } 3230 3231 /* 3232 * @brief Set Advertisement Paramters 3233 * @param adv_int_min 3234 * @param adv_int_max 3235 * @param adv_type 3236 * @param direct_address_type 3237 * @param direct_address 3238 * @param channel_map 3239 * @param filter_policy 3240 * 3241 * @note own_address_type is used from gap_random_address_set_mode 3242 */ 3243 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 3244 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 3245 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, gap_random_adress_type, 3246 direct_address_typ, direct_address, channel_map, filter_policy); 3247 } 3248 3249