1 /* 2 * Copyright (C) 2017 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 * 17 * THIS SOFTWARE IS PROVIDED BY MATTHIAS RINGWALD AND CONTRIBUTORS 18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 20 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 21 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 23 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 24 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 25 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 26 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 27 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 */ 31 32 #define BTSTACK_FILE__ "btstack_crypto.c" 33 34 /* 35 * btstack_crypto.h 36 * 37 * Central place for all crypto-related functions with completion callbacks to allow 38 * using of MCU crypto peripherals or the Bluetooth controller 39 */ 40 41 #include "btstack_crypto.h" 42 43 #include "btstack_debug.h" 44 #include "btstack_event.h" 45 #include "btstack_linked_list.h" 46 #include "btstack_util.h" 47 #include "hci.h" 48 49 // 50 // AES128 Configuration 51 // 52 53 // By default, AES128 is computed by Bluetooth Controller using HCI Command/Event asynchronously 54 // as fallback/alternative, a software implementation can be used 55 // configure ECC implementations 56 #if defined(HAVE_AES128) && defined(ENABLE_SOFTWARE_AES128) 57 #error "If you have custom AES128 implementation (HAVE_AES128), please disable software AES128 (ENABLE_SOFTWARE_AES128) in bstack_config.h" 58 #endif 59 60 #ifdef ENABLE_SOFTWARE_AES128 61 #define HAVE_AES128 62 #include "rijndael.h" 63 #endif 64 65 #ifdef HAVE_AES128 66 #define USE_BTSTACK_AES128 67 #endif 68 69 // 70 // ECC Configuration 71 // 72 73 // backwards-compatitility ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS -> ENABLE_MICRO_ECC_P256 74 #if defined(ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS) && !defined(ENABLE_MICRO_ECC_P256) 75 #define ENABLE_MICRO_ECC_P256 76 #endif 77 78 // configure ECC implementations 79 #if defined(ENABLE_MICRO_ECC_P256) && defined(HAVE_MBEDTLS_ECC_P256) 80 #error "If you have mbedTLS (HAVE_MBEDTLS_ECC_P256), please disable uECC (ENABLE_MICRO_ECC_P256) in bstack_config.h" 81 #endif 82 83 // Software ECC-P256 implementation provided by micro-ecc 84 #ifdef ENABLE_MICRO_ECC_P256 85 #define ENABLE_ECC_P256 86 #define USE_MICRO_ECC_P256 87 #define USE_SOFTWARE_ECC_P256_IMPLEMENTATION 88 #include "uECC.h" 89 #endif 90 91 // Software ECC-P256 implementation provided by mbedTLS 92 #ifdef HAVE_MBEDTLS_ECC_P256 93 #define ENABLE_ECC_P256 94 #define USE_MBEDTLS_ECC_P256 95 #define USE_SOFTWARE_ECC_P256_IMPLEMENTATION 96 #include "mbedtls/config.h" 97 #include "mbedtls/platform.h" 98 #include "mbedtls/ecp.h" 99 #endif 100 101 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(ENABLE_ECC_P256) 102 #define ENABLE_ECC_P256 103 #endif 104 105 // debugging 106 // #define DEBUG_CCM 107 108 typedef enum { 109 CMAC_IDLE, 110 CMAC_CALC_SUBKEYS, 111 CMAC_W4_SUBKEYS, 112 CMAC_CALC_MI, 113 CMAC_W4_MI, 114 CMAC_CALC_MLAST, 115 CMAC_W4_MLAST 116 } btstack_crypto_cmac_state_t; 117 118 typedef enum { 119 ECC_P256_KEY_GENERATION_IDLE, 120 ECC_P256_KEY_GENERATION_GENERATING_RANDOM, 121 ECC_P256_KEY_GENERATION_ACTIVE, 122 ECC_P256_KEY_GENERATION_W4_KEY, 123 ECC_P256_KEY_GENERATION_DONE, 124 } btstack_crypto_ecc_p256_key_generation_state_t; 125 126 static void btstack_crypto_run(void); 127 128 static const uint8_t zero[16] = { 0 }; 129 130 static uint8_t btstack_crypto_initialized; 131 static btstack_linked_list_t btstack_crypto_operations; 132 static btstack_packet_callback_registration_t hci_event_callback_registration; 133 static uint8_t btstack_crypto_wait_for_hci_result; 134 135 // state for AES-CMAC 136 #ifndef USE_BTSTACK_AES128 137 static btstack_crypto_cmac_state_t btstack_crypto_cmac_state; 138 static sm_key_t btstack_crypto_cmac_k; 139 static sm_key_t btstack_crypto_cmac_x; 140 static sm_key_t btstack_crypto_cmac_subkey; 141 static uint8_t btstack_crypto_cmac_block_current; 142 static uint8_t btstack_crypto_cmac_block_count; 143 #endif 144 145 // state for AES-CCM 146 static uint8_t btstack_crypto_ccm_s[16]; 147 148 #ifdef ENABLE_ECC_P256 149 150 static uint8_t btstack_crypto_ecc_p256_public_key[64]; 151 static uint8_t btstack_crypto_ecc_p256_random[64]; 152 static uint8_t btstack_crypto_ecc_p256_random_len; 153 static uint8_t btstack_crypto_ecc_p256_random_offset; 154 static btstack_crypto_ecc_p256_key_generation_state_t btstack_crypto_ecc_p256_key_generation_state; 155 156 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 157 static uint8_t btstack_crypto_ecc_p256_d[32]; 158 #endif 159 160 // Software ECDH implementation provided by mbedtls 161 #ifdef USE_MBEDTLS_ECC_P256 162 static mbedtls_ecp_group mbedtls_ec_group; 163 #endif 164 165 #endif /* ENABLE_ECC_P256 */ 166 167 #ifdef ENABLE_SOFTWARE_AES128 168 // AES128 using public domain rijndael implementation 169 void btstack_aes128_calc(const uint8_t * key, const uint8_t * plaintext, uint8_t * ciphertext){ 170 uint32_t rk[RKLENGTH(KEYBITS)]; 171 int nrounds = rijndaelSetupEncrypt(rk, &key[0], KEYBITS); 172 rijndaelEncrypt(rk, nrounds, plaintext, ciphertext); 173 } 174 #endif 175 176 static void btstack_crypto_done(btstack_crypto_t * btstack_crypto){ 177 btstack_linked_list_pop(&btstack_crypto_operations); 178 (*btstack_crypto->context_callback.callback)(btstack_crypto->context_callback.context); 179 } 180 181 static void btstack_crypto_cmac_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 182 int i; 183 int carry = 0; 184 for (i=len-1; i >= 0 ; i--){ 185 int new_carry = data[i] >> 7; 186 data[i] = (data[i] << 1) | carry; 187 carry = new_carry; 188 } 189 } 190 191 static uint8_t btstack_crypto_cmac_get_byte(btstack_crypto_aes128_cmac_t * btstack_crypto_cmac, uint16_t pos){ 192 if (btstack_crypto_cmac->btstack_crypto.operation == BTSTACK_CRYPTO_CMAC_GENERATOR){ 193 return (*btstack_crypto_cmac->data.get_byte_callback)(pos); 194 } else { 195 return btstack_crypto_cmac->data.message[pos]; 196 } 197 } 198 199 #ifdef USE_BTSTACK_AES128 200 201 static void btstack_crypto_cmac_calc_subkeys(sm_key_t k0, sm_key_t k1, sm_key_t k2){ 202 memcpy(k1, k0, 16); 203 btstack_crypto_cmac_shift_left_by_one_bit_inplace(16, k1); 204 if (k0[0] & 0x80){ 205 k1[15] ^= 0x87; 206 } 207 memcpy(k2, k1, 16); 208 btstack_crypto_cmac_shift_left_by_one_bit_inplace(16, k2); 209 if (k1[0] & 0x80){ 210 k2[15] ^= 0x87; 211 } 212 } 213 214 static void btstack_crypto_cmac_calc(btstack_crypto_aes128_cmac_t * btstack_crypto_cmac) { 215 sm_key_t k0, k1, k2; 216 uint16_t i; 217 218 btstack_aes128_calc(btstack_crypto_cmac->key, zero, k0); 219 btstack_crypto_cmac_calc_subkeys(k0, k1, k2); 220 221 uint16_t cmac_block_count = (btstack_crypto_cmac->size + 15) / 16; 222 223 // step 3: .. 224 if (cmac_block_count==0){ 225 cmac_block_count = 1; 226 } 227 228 // Step 5 229 sm_key_t cmac_x; 230 memset(cmac_x, 0, 16); 231 232 // Step 6 233 sm_key_t cmac_y; 234 int block; 235 for (block = 0 ; block < cmac_block_count-1 ; block++){ 236 for (i=0;i<16;i++){ 237 cmac_y[i] = cmac_x[i] ^ btstack_crypto_cmac_get_byte(btstack_crypto_cmac, (block*16) + i); 238 } 239 btstack_aes128_calc(btstack_crypto_cmac->key, cmac_y, cmac_x); 240 } 241 242 // step 4: set m_last 243 sm_key_t cmac_m_last; 244 bool last_block_complete = btstack_crypto_cmac->size != 0 && (btstack_crypto_cmac->size & 0x0f) == 0; 245 if (last_block_complete){ 246 for (i=0;i<16;i++){ 247 cmac_m_last[i] = btstack_crypto_cmac_get_byte(btstack_crypto_cmac, btstack_crypto_cmac->size - 16 + i) ^ k1[i]; 248 } 249 } else { 250 uint16_t valid_octets_in_last_block = btstack_crypto_cmac->size & 0x0f; 251 for (i=0;i<16;i++){ 252 if (i < valid_octets_in_last_block){ 253 cmac_m_last[i] = btstack_crypto_cmac_get_byte(btstack_crypto_cmac, (btstack_crypto_cmac->size & 0xfff0) + i) ^ k2[i]; 254 continue; 255 } 256 if (i == valid_octets_in_last_block){ 257 cmac_m_last[i] = 0x80 ^ k2[i]; 258 continue; 259 } 260 cmac_m_last[i] = k2[i]; 261 } 262 } 263 264 for (i=0;i<16;i++){ 265 cmac_y[i] = cmac_x[i] ^ cmac_m_last[i]; 266 } 267 268 // Step 7 269 btstack_aes128_calc(btstack_crypto_cmac->key, cmac_y, btstack_crypto_cmac->hash); 270 } 271 #else 272 273 static void btstack_crypto_aes128_start(const sm_key_t key, const sm_key_t plaintext){ 274 uint8_t key_flipped[16]; 275 uint8_t plaintext_flipped[16]; 276 reverse_128(key, key_flipped); 277 reverse_128(plaintext, plaintext_flipped); 278 btstack_crypto_wait_for_hci_result = 1; 279 hci_send_cmd(&hci_le_encrypt, key_flipped, plaintext_flipped); 280 } 281 282 static inline void btstack_crypto_cmac_next_state(void){ 283 btstack_crypto_cmac_state = (btstack_crypto_cmac_state_t) (((int)btstack_crypto_cmac_state) + 1); 284 } 285 286 static int btstack_crypto_cmac_last_block_complete(btstack_crypto_aes128_cmac_t * btstack_crypto_cmac){ 287 uint16_t len = btstack_crypto_cmac->size; 288 if (len == 0) return 0; 289 return (len & 0x0f) == 0; 290 } 291 292 static void btstack_crypto_cmac_handle_aes_engine_ready(btstack_crypto_aes128_cmac_t * btstack_crypto_cmac){ 293 switch (btstack_crypto_cmac_state){ 294 case CMAC_CALC_SUBKEYS: { 295 btstack_crypto_cmac_next_state(); 296 btstack_crypto_aes128_start(btstack_crypto_cmac_k, zero); 297 break; 298 } 299 case CMAC_CALC_MI: { 300 int j; 301 sm_key_t y; 302 for (j=0;j<16;j++){ 303 y[j] = btstack_crypto_cmac_x[j] ^ btstack_crypto_cmac_get_byte(btstack_crypto_cmac, (btstack_crypto_cmac_block_current*16) + j); 304 } 305 btstack_crypto_cmac_block_current++; 306 btstack_crypto_cmac_next_state(); 307 btstack_crypto_aes128_start(btstack_crypto_cmac_k, y); 308 break; 309 } 310 case CMAC_CALC_MLAST: { 311 sm_key_t k1; 312 (void)memcpy(k1, btstack_crypto_cmac_subkey, 16); 313 btstack_crypto_cmac_shift_left_by_one_bit_inplace(16, k1); 314 if (btstack_crypto_cmac_subkey[0] & 0x80){ 315 k1[15] ^= 0x87; 316 } 317 sm_key_t k2; 318 (void)memcpy(k2, k1, 16); 319 btstack_crypto_cmac_shift_left_by_one_bit_inplace(16, k2); 320 if (k1[0] & 0x80){ 321 k2[15] ^= 0x87; 322 } 323 324 log_info_key("k", btstack_crypto_cmac_k); 325 log_info_key("k1", k1); 326 log_info_key("k2", k2); 327 328 // step 4: set m_last 329 int i; 330 sm_key_t btstack_crypto_cmac_m_last; 331 if (btstack_crypto_cmac_last_block_complete(btstack_crypto_cmac)){ 332 for (i=0;i<16;i++){ 333 btstack_crypto_cmac_m_last[i] = btstack_crypto_cmac_get_byte(btstack_crypto_cmac, btstack_crypto_cmac->size - 16 + i) ^ k1[i]; 334 } 335 } else { 336 int valid_octets_in_last_block = btstack_crypto_cmac->size & 0x0f; 337 for (i=0;i<16;i++){ 338 if (i < valid_octets_in_last_block){ 339 btstack_crypto_cmac_m_last[i] = btstack_crypto_cmac_get_byte(btstack_crypto_cmac, (btstack_crypto_cmac->size & 0xfff0) + i) ^ k2[i]; 340 continue; 341 } 342 if (i == valid_octets_in_last_block){ 343 btstack_crypto_cmac_m_last[i] = 0x80 ^ k2[i]; 344 continue; 345 } 346 btstack_crypto_cmac_m_last[i] = k2[i]; 347 } 348 } 349 sm_key_t y; 350 for (i=0;i<16;i++){ 351 y[i] = btstack_crypto_cmac_x[i] ^ btstack_crypto_cmac_m_last[i]; 352 } 353 btstack_crypto_cmac_block_current++; 354 btstack_crypto_cmac_next_state(); 355 btstack_crypto_aes128_start(btstack_crypto_cmac_k, y); 356 break; 357 } 358 default: 359 log_info("btstack_crypto_cmac_handle_aes_engine_ready called in state %u", btstack_crypto_cmac_state); 360 break; 361 } 362 } 363 364 static void btstack_crypto_cmac_handle_encryption_result(btstack_crypto_aes128_cmac_t * btstack_crypto_cmac, sm_key_t data){ 365 switch (btstack_crypto_cmac_state){ 366 case CMAC_W4_SUBKEYS: 367 (void)memcpy(btstack_crypto_cmac_subkey, data, 16); 368 // next 369 btstack_crypto_cmac_state = (btstack_crypto_cmac_block_current < (btstack_crypto_cmac_block_count - 1)) ? CMAC_CALC_MI : CMAC_CALC_MLAST; 370 break; 371 case CMAC_W4_MI: 372 (void)memcpy(btstack_crypto_cmac_x, data, 16); 373 btstack_crypto_cmac_state = (btstack_crypto_cmac_block_current < (btstack_crypto_cmac_block_count - 1)) ? CMAC_CALC_MI : CMAC_CALC_MLAST; 374 break; 375 case CMAC_W4_MLAST: 376 // done 377 log_info("Setting CMAC Engine to IDLE"); 378 btstack_crypto_cmac_state = CMAC_IDLE; 379 log_info_key("CMAC", data); 380 (void)memcpy(btstack_crypto_cmac->hash, data, 16); 381 btstack_linked_list_pop(&btstack_crypto_operations); 382 (*btstack_crypto_cmac->btstack_crypto.context_callback.callback)(btstack_crypto_cmac->btstack_crypto.context_callback.context); 383 break; 384 default: 385 log_info("btstack_crypto_cmac_handle_encryption_result called in state %u", btstack_crypto_cmac_state); 386 break; 387 } 388 } 389 390 static void btstack_crypto_cmac_start(btstack_crypto_aes128_cmac_t * btstack_crypto_cmac){ 391 392 (void)memcpy(btstack_crypto_cmac_k, btstack_crypto_cmac->key, 16); 393 memset(btstack_crypto_cmac_x, 0, 16); 394 btstack_crypto_cmac_block_current = 0; 395 396 // step 2: n := ceil(len/const_Bsize); 397 btstack_crypto_cmac_block_count = (btstack_crypto_cmac->size + 15) / 16; 398 399 // step 3: .. 400 if (btstack_crypto_cmac_block_count==0){ 401 btstack_crypto_cmac_block_count = 1; 402 } 403 log_info("btstack_crypto_cmac_start: len %u, block count %u", btstack_crypto_cmac->size, btstack_crypto_cmac_block_count); 404 405 // first, we need to compute l for k1, k2, and m_last 406 btstack_crypto_cmac_state = CMAC_CALC_SUBKEYS; 407 408 // let's go 409 btstack_crypto_cmac_handle_aes_engine_ready(btstack_crypto_cmac); 410 } 411 #endif 412 413 /* 414 To encrypt the message data we use Counter (CTR) mode. We first 415 define the key stream blocks by: 416 417 S_i := E( K, A_i ) for i=0, 1, 2, ... 418 419 The values A_i are formatted as follows, where the Counter field i is 420 encoded in most-significant-byte first order: 421 422 Octet Number Contents 423 ------------ --------- 424 0 Flags 425 1 ... 15-L Nonce N 426 16-L ... 15 Counter i 427 428 Bit Number Contents 429 ---------- ---------------------- 430 7 Reserved (always zero) 431 6 Reserved (always zero) 432 5 ... 3 Zero 433 2 ... 0 L' 434 */ 435 436 static void btstack_crypto_ccm_setup_a_i(btstack_crypto_ccm_t * btstack_crypto_ccm, uint16_t counter){ 437 btstack_crypto_ccm_s[0] = 1; // L' = L - 1 438 (void)memcpy(&btstack_crypto_ccm_s[1], btstack_crypto_ccm->nonce, 13); 439 big_endian_store_16(btstack_crypto_ccm_s, 14, counter); 440 #ifdef DEBUG_CCM 441 printf("btstack_crypto_ccm_setup_a_%u\n", counter); 442 printf("%16s: ", "ai"); 443 printf_hexdump(btstack_crypto_ccm_s, 16); 444 #endif 445 } 446 447 /* 448 The first step is to compute the authentication field T. This is 449 done using CBC-MAC [MAC]. We first define a sequence of blocks B_0, 450 B_1, ..., B_n and then apply CBC-MAC to these blocks. 451 452 The first block B_0 is formatted as follows, where l(m) is encoded in 453 most-significant-byte first order: 454 455 Octet Number Contents 456 ------------ --------- 457 0 Flags 458 1 ... 15-L Nonce N 459 16-L ... 15 l(m) 460 461 Within the first block B_0, the Flags field is formatted as follows: 462 463 Bit Number Contents 464 ---------- ---------------------- 465 7 Reserved (always zero) 466 6 Adata 467 5 ... 3 M' 468 2 ... 0 L' 469 */ 470 471 static void btstack_crypto_ccm_setup_b_0(btstack_crypto_ccm_t * btstack_crypto_ccm, uint8_t * b0){ 472 uint8_t m_prime = (btstack_crypto_ccm->auth_len - 2) / 2; 473 uint8_t Adata = btstack_crypto_ccm->aad_len ? 1 : 0; 474 b0[0] = (Adata << 6) | (m_prime << 3) | 1 ; // Adata, M', L' = L - 1 475 (void)memcpy(&b0[1], btstack_crypto_ccm->nonce, 13); 476 big_endian_store_16(b0, 14, btstack_crypto_ccm->message_len); 477 #ifdef DEBUG_CCM 478 printf("%16s: ", "B0"); 479 printf_hexdump(b0, 16); 480 #endif 481 } 482 483 #ifdef ENABLE_ECC_P256 484 485 static void btstack_crypto_log_ec_publickey(const uint8_t * ec_q){ 486 log_info("Elliptic curve: X"); 487 log_info_hexdump(&ec_q[0],32); 488 log_info("Elliptic curve: Y"); 489 log_info_hexdump(&ec_q[32],32); 490 } 491 492 #if (defined(USE_MICRO_ECC_P256) && !defined(WICED_VERSION)) || defined(USE_MBEDTLS_ECC_P256) 493 // @return OK 494 static int sm_generate_f_rng(unsigned char * buffer, unsigned size){ 495 if (btstack_crypto_ecc_p256_key_generation_state != ECC_P256_KEY_GENERATION_ACTIVE) return 0; 496 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, btstack_crypto_ecc_p256_random_offset); 497 while (size) { 498 *buffer++ = btstack_crypto_ecc_p256_random[btstack_crypto_ecc_p256_random_offset++]; 499 size--; 500 } 501 return 1; 502 } 503 #endif 504 #ifdef USE_MBEDTLS_ECC_P256 505 // @return error - just wrap sm_generate_f_rng 506 static int sm_generate_f_rng_mbedtls(void * context, unsigned char * buffer, size_t size){ 507 UNUSED(context); 508 return sm_generate_f_rng(buffer, size) == 0; 509 } 510 #endif /* USE_MBEDTLS_ECC_P256 */ 511 512 static void btstack_crypto_ecc_p256_generate_key_software(void){ 513 514 btstack_crypto_ecc_p256_random_offset = 0; 515 516 // generate EC key 517 #ifdef USE_MICRO_ECC_P256 518 519 #ifndef WICED_VERSION 520 log_info("set uECC RNG for initial key generation with 64 random bytes"); 521 // micro-ecc from WICED SDK uses its wiced_crypto_get_random by default - no need to set it 522 uECC_set_rng(&sm_generate_f_rng); 523 #endif /* WICED_VERSION */ 524 525 #if uECC_SUPPORTS_secp256r1 526 // standard version 527 uECC_make_key(btstack_crypto_ecc_p256_public_key, btstack_crypto_ecc_p256_d, uECC_secp256r1()); 528 529 // disable RNG again, as returning no randmon data lets shared key generation fail 530 log_info("disable uECC RNG in standard version after key generation"); 531 uECC_set_rng(NULL); 532 #else 533 // static version 534 uECC_make_key(btstack_crypto_ecc_p256_public_key, btstack_crypto_ecc_p256_d); 535 #endif 536 #endif /* USE_MICRO_ECC_P256 */ 537 538 #ifdef USE_MBEDTLS_ECC_P256 539 mbedtls_mpi d; 540 mbedtls_ecp_point P; 541 mbedtls_mpi_init(&d); 542 mbedtls_ecp_point_init(&P); 543 int res = mbedtls_ecp_gen_keypair(&mbedtls_ec_group, &d, &P, &sm_generate_f_rng_mbedtls, NULL); 544 log_info("gen keypair %x", res); 545 mbedtls_mpi_write_binary(&P.X, &btstack_crypto_ecc_p256_public_key[0], 32); 546 mbedtls_mpi_write_binary(&P.Y, &btstack_crypto_ecc_p256_public_key[32], 32); 547 mbedtls_mpi_write_binary(&d, btstack_crypto_ecc_p256_d, 32); 548 mbedtls_ecp_point_free(&P); 549 mbedtls_mpi_free(&d); 550 #endif /* USE_MBEDTLS_ECC_P256 */ 551 } 552 553 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 554 static void btstack_crypto_ecc_p256_calculate_dhkey_software(btstack_crypto_ecc_p256_t * btstack_crypto_ec_p192){ 555 memset(btstack_crypto_ec_p192->dhkey, 0, 32); 556 557 #ifdef USE_MICRO_ECC_P256 558 #if uECC_SUPPORTS_secp256r1 559 // standard version 560 uECC_shared_secret(btstack_crypto_ec_p192->public_key, btstack_crypto_ecc_p256_d, btstack_crypto_ec_p192->dhkey, uECC_secp256r1()); 561 #else 562 // static version 563 uECC_shared_secret(btstack_crypto_ec_p192->public_key, btstack_crypto_ecc_p256_d, btstack_crypto_ec_p192->dhkey); 564 #endif 565 #endif 566 567 #ifdef USE_MBEDTLS_ECC_P256 568 // da * Pb 569 mbedtls_mpi d; 570 mbedtls_ecp_point Q; 571 mbedtls_ecp_point DH; 572 mbedtls_mpi_init(&d); 573 mbedtls_ecp_point_init(&Q); 574 mbedtls_ecp_point_init(&DH); 575 mbedtls_mpi_read_binary(&d, btstack_crypto_ecc_p256_d, 32); 576 mbedtls_mpi_read_binary(&Q.X, &btstack_crypto_ec_p192->public_key[0] , 32); 577 mbedtls_mpi_read_binary(&Q.Y, &btstack_crypto_ec_p192->public_key[32], 32); 578 mbedtls_mpi_lset(&Q.Z, 1); 579 mbedtls_ecp_mul(&mbedtls_ec_group, &DH, &d, &Q, NULL, NULL); 580 mbedtls_mpi_write_binary(&DH.X, btstack_crypto_ec_p192->dhkey, 32); 581 mbedtls_ecp_point_free(&DH); 582 mbedtls_mpi_free(&d); 583 mbedtls_ecp_point_free(&Q); 584 #endif 585 586 log_info("dhkey"); 587 log_info_hexdump(btstack_crypto_ec_p192->dhkey, 32); 588 } 589 #endif 590 591 #endif 592 593 static void btstack_crypto_ccm_next_block(btstack_crypto_ccm_t * btstack_crypto_ccm, btstack_crypto_ccm_state_t state_when_done){ 594 uint16_t bytes_to_process = btstack_min(btstack_crypto_ccm->block_len, 16); 595 // next block 596 btstack_crypto_ccm->counter++; 597 btstack_crypto_ccm->input += bytes_to_process; 598 btstack_crypto_ccm->output += bytes_to_process; 599 btstack_crypto_ccm->block_len -= bytes_to_process; 600 btstack_crypto_ccm->message_len -= bytes_to_process; 601 #ifdef DEBUG_CCM 602 printf("btstack_crypto_ccm_next_block (message len %u, block_len %u)\n", btstack_crypto_ccm->message_len, btstack_crypto_ccm->block_len); 603 #endif 604 if (btstack_crypto_ccm->message_len == 0){ 605 btstack_crypto_ccm->state = CCM_CALCULATE_S0; 606 } else { 607 btstack_crypto_ccm->state = state_when_done; 608 if (btstack_crypto_ccm->block_len == 0){ 609 btstack_crypto_done(&btstack_crypto_ccm->btstack_crypto); 610 } 611 } 612 } 613 614 // If Controller is used for AES128, data is little endian 615 static void btstack_crypto_ccm_handle_s0(btstack_crypto_ccm_t * btstack_crypto_ccm, const uint8_t * data){ 616 int i; 617 for (i=0;i<16;i++){ 618 #ifdef USE_BTSTACK_AES128 619 btstack_crypto_ccm->x_i[i] = btstack_crypto_ccm->x_i[i] ^ data[i]; 620 #else 621 btstack_crypto_ccm->x_i[i] = btstack_crypto_ccm->x_i[i] ^ data[15-i]; 622 #endif 623 } 624 btstack_crypto_done(&btstack_crypto_ccm->btstack_crypto); 625 } 626 627 // If Controller is used for AES128, data is little endian 628 static void btstack_crypto_ccm_handle_sn(btstack_crypto_ccm_t * btstack_crypto_ccm, const uint8_t * data){ 629 int i; 630 uint16_t bytes_to_process = btstack_min(btstack_crypto_ccm->block_len, 16); 631 for (i=0;i<bytes_to_process;i++){ 632 #ifdef USE_BTSTACK_AES128 633 btstack_crypto_ccm->output[i] = btstack_crypto_ccm->input[i] ^ data[i]; 634 #else 635 btstack_crypto_ccm->output[i] = btstack_crypto_ccm->input[i] ^ data[15-i]; 636 #endif 637 } 638 switch (btstack_crypto_ccm->btstack_crypto.operation){ 639 case BTSTACK_CRYPTO_CCM_DECRYPT_BLOCK: 640 btstack_crypto_ccm->state = CCM_CALCULATE_XN; 641 break; 642 case BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK: 643 btstack_crypto_ccm_next_block(btstack_crypto_ccm, CCM_CALCULATE_XN); 644 break; 645 default: 646 btstack_assert(false); 647 break; 648 } 649 } 650 651 static void btstack_crypto_ccm_handle_aad_xn(btstack_crypto_ccm_t * btstack_crypto_ccm) { 652 #ifdef DEBUG_CCM 653 printf("%16s: ", "Xn+1 AAD"); 654 printf_hexdump(btstack_crypto_ccm->x_i, 16); 655 #endif 656 // more aad? 657 if (btstack_crypto_ccm->aad_offset < (btstack_crypto_ccm->aad_len + 2)){ 658 btstack_crypto_ccm->state = CCM_CALCULATE_AAD_XN; 659 } else { 660 // done 661 btstack_crypto_done((btstack_crypto_t *) btstack_crypto_ccm); 662 } 663 } 664 665 static void btstack_crypto_ccm_handle_x1(btstack_crypto_ccm_t * btstack_crypto_ccm) { 666 #ifdef DEBUG_CCM 667 printf("%16s: ", "Xi"); 668 printf_hexdump(btstack_crypto_ccm->x_i, 16); 669 #endif 670 switch (btstack_crypto_ccm->btstack_crypto.operation){ 671 case BTSTACK_CRYPTO_CCM_DIGEST_BLOCK: 672 btstack_crypto_ccm->aad_remainder_len = 0; 673 btstack_crypto_ccm->state = CCM_CALCULATE_AAD_XN; 674 break; 675 case BTSTACK_CRYPTO_CCM_DECRYPT_BLOCK: 676 btstack_crypto_ccm->state = CCM_CALCULATE_SN; 677 break; 678 case BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK: 679 btstack_crypto_ccm->state = CCM_CALCULATE_XN; 680 break; 681 default: 682 btstack_assert(false); 683 break; 684 } 685 } 686 687 688 static void btstack_crypto_ccm_calc_s0(btstack_crypto_ccm_t * btstack_crypto_ccm){ 689 #ifdef DEBUG_CCM 690 printf("btstack_crypto_ccm_calc_s0\n"); 691 #endif 692 btstack_crypto_ccm->state = CCM_W4_S0; 693 btstack_crypto_ccm_setup_a_i(btstack_crypto_ccm, 0); 694 #ifdef USE_BTSTACK_AES128 695 uint8_t data[16]; 696 btstack_aes128_calc(btstack_crypto_ccm->key, btstack_crypto_ccm_s, data); 697 #ifdef DEBUG_CCM 698 printf("%16s: ", "S0"); 699 printf_hexdump(data, 16); 700 #endif 701 btstack_crypto_ccm_handle_s0(btstack_crypto_ccm, data); 702 #else 703 btstack_crypto_aes128_start(btstack_crypto_ccm->key, btstack_crypto_ccm_s); 704 #endif 705 } 706 707 static void btstack_crypto_ccm_calc_sn(btstack_crypto_ccm_t * btstack_crypto_ccm){ 708 #ifdef DEBUG_CCM 709 printf("btstack_crypto_ccm_calc_s%u\n", btstack_crypto_ccm->counter); 710 #endif 711 btstack_crypto_ccm->state = CCM_W4_SN; 712 btstack_crypto_ccm_setup_a_i(btstack_crypto_ccm, btstack_crypto_ccm->counter); 713 #ifdef USE_BTSTACK_AES128 714 uint8_t data[16]; 715 btstack_aes128_calc(btstack_crypto_ccm->key, btstack_crypto_ccm_s, data); 716 #ifdef DEBUG_CCM 717 printf("%16s: ", "Sn"); 718 printf_hexdump(data, 16); 719 #endif 720 switch (btstack_crypto_ccm->btstack_crypto.operation){ 721 case BTSTACK_CRYPTO_CCM_DECRYPT_BLOCK: 722 btstack_crypto_ccm->state = CCM_CALCULATE_XN; 723 break; 724 case BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK: 725 btstack_crypto_ccm_next_block(btstack_crypto_ccm, CCM_CALCULATE_XN); 726 break; 727 default: 728 btstack_assert(false); 729 break; 730 } 731 #else 732 btstack_crypto_aes128_start(btstack_crypto_ccm->key, btstack_crypto_ccm_s); 733 #endif 734 } 735 736 static void btstack_crypto_ccm_calc_x1(btstack_crypto_ccm_t * btstack_crypto_ccm){ 737 uint8_t btstack_crypto_ccm_buffer[16]; 738 btstack_crypto_ccm->state = CCM_W4_X1; 739 btstack_crypto_ccm_setup_b_0(btstack_crypto_ccm, btstack_crypto_ccm_buffer); 740 #ifdef USE_BTSTACK_AES128 741 btstack_aes128_calc(btstack_crypto_ccm->key, btstack_crypto_ccm_buffer, btstack_crypto_ccm->x_i); 742 btstack_crypto_ccm_handle_x1(btstack_crypto_ccm); 743 #else 744 btstack_crypto_aes128_start(btstack_crypto_ccm->key, btstack_crypto_ccm_buffer); 745 #endif 746 } 747 748 static void btstack_crypto_ccm_handle_xn(btstack_crypto_ccm_t * btstack_crypto_ccm) { 749 #ifdef DEBUG_CCM 750 printf("%16s: ", "Xn+1"); 751 printf_hexdump(btstack_crypto_ccm->x_i, 16); 752 #endif 753 switch (btstack_crypto_ccm->btstack_crypto.operation){ 754 case BTSTACK_CRYPTO_CCM_DECRYPT_BLOCK: 755 btstack_crypto_ccm_next_block(btstack_crypto_ccm, CCM_CALCULATE_SN); 756 break; 757 case BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK: 758 btstack_crypto_ccm->state = CCM_CALCULATE_SN; 759 break; 760 default: 761 btstack_assert(false); 762 break; 763 } 764 } 765 766 static void btstack_crypto_ccm_calc_xn(btstack_crypto_ccm_t * btstack_crypto_ccm, const uint8_t * plaintext){ 767 uint8_t btstack_crypto_ccm_buffer[16]; 768 btstack_crypto_ccm->state = CCM_W4_XN; 769 770 #ifdef DEBUG_CCM 771 printf("%16s: ", "bn"); 772 printf_hexdump(plaintext, 16); 773 #endif 774 uint8_t i; 775 uint8_t bytes_to_decrypt = btstack_crypto_ccm->block_len; 776 // use explicit min implementation as c-stat worried about out-of-bounds-reads 777 if (bytes_to_decrypt > 16) { 778 bytes_to_decrypt = 16; 779 } 780 for (i = 0; i < bytes_to_decrypt ; i++){ 781 btstack_crypto_ccm_buffer[i] = btstack_crypto_ccm->x_i[i] ^ plaintext[i]; 782 } 783 (void)memcpy(&btstack_crypto_ccm_buffer[i], &btstack_crypto_ccm->x_i[i], 784 16 - bytes_to_decrypt); 785 #ifdef DEBUG_CCM 786 printf("%16s: ", "Xn XOR bn"); 787 printf_hexdump(btstack_crypto_ccm_buffer, 16); 788 #endif 789 790 #ifdef USE_BTSTACK_AES128 791 btstack_aes128_calc(btstack_crypto_ccm->key, btstack_crypto_ccm_buffer, btstack_crypto_ccm->x_i); 792 btstack_crypto_ccm_handle_xn(btstack_crypto_ccm); 793 #else 794 btstack_crypto_aes128_start(btstack_crypto_ccm->key, btstack_crypto_ccm_buffer); 795 #endif 796 } 797 798 static void btstack_crypto_ccm_calc_aad_xn(btstack_crypto_ccm_t * btstack_crypto_ccm){ 799 // store length 800 if (btstack_crypto_ccm->aad_offset == 0){ 801 uint8_t len_buffer[2]; 802 big_endian_store_16(len_buffer, 0, btstack_crypto_ccm->aad_len); 803 btstack_crypto_ccm->x_i[0] ^= len_buffer[0]; 804 btstack_crypto_ccm->x_i[1] ^= len_buffer[1]; 805 btstack_crypto_ccm->aad_remainder_len += 2; 806 btstack_crypto_ccm->aad_offset += 2; 807 } 808 809 // fill from input 810 uint16_t bytes_free = 16 - btstack_crypto_ccm->aad_remainder_len; 811 uint16_t bytes_to_copy = btstack_min(bytes_free, btstack_crypto_ccm->block_len); 812 while (bytes_to_copy){ 813 btstack_crypto_ccm->x_i[btstack_crypto_ccm->aad_remainder_len++] ^= *btstack_crypto_ccm->input++; 814 btstack_crypto_ccm->aad_offset++; 815 btstack_crypto_ccm->block_len--; 816 bytes_to_copy--; 817 bytes_free--; 818 } 819 820 // if last block, fill with zeros 821 if (btstack_crypto_ccm->aad_offset == (btstack_crypto_ccm->aad_len + 2)){ 822 btstack_crypto_ccm->aad_remainder_len = 16; 823 } 824 // if not full, notify done 825 if (btstack_crypto_ccm->aad_remainder_len < 16){ 826 btstack_crypto_done(&btstack_crypto_ccm->btstack_crypto); 827 return; 828 } 829 830 // encrypt block 831 #ifdef DEBUG_CCM 832 printf("%16s: ", "Xn XOR Bn (aad)"); 833 printf_hexdump(btstack_crypto_ccm->x_i, 16); 834 #endif 835 836 btstack_crypto_ccm->aad_remainder_len = 0; 837 btstack_crypto_ccm->state = CCM_W4_AAD_XN; 838 #ifdef USE_BTSTACK_AES128 839 btstack_aes128_calc(btstack_crypto_ccm->key, btstack_crypto_ccm->x_i, btstack_crypto_ccm->x_i); 840 btstack_crypto_ccm_handle_aad_xn(btstack_crypto_ccm); 841 #else 842 btstack_crypto_aes128_start(btstack_crypto_ccm->key, btstack_crypto_ccm->x_i); 843 #endif 844 } 845 846 static void btstack_crypto_run(void){ 847 848 btstack_crypto_aes128_t * btstack_crypto_aes128; 849 btstack_crypto_ccm_t * btstack_crypto_ccm; 850 btstack_crypto_aes128_cmac_t * btstack_crypto_cmac; 851 #ifdef ENABLE_ECC_P256 852 btstack_crypto_ecc_p256_t * btstack_crypto_ec_p192; 853 #endif 854 855 // stack up and running? 856 if (hci_get_state() != HCI_STATE_WORKING) return; 857 858 // try to do as much as possible 859 while (true){ 860 861 // anything to do? 862 if (btstack_linked_list_empty(&btstack_crypto_operations)) return; 863 864 // already active? 865 if (btstack_crypto_wait_for_hci_result) return; 866 867 // can send a command? 868 if (!hci_can_send_command_packet_now()) return; 869 870 // ok, find next task 871 btstack_crypto_t * btstack_crypto = (btstack_crypto_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 872 switch (btstack_crypto->operation){ 873 case BTSTACK_CRYPTO_RANDOM: 874 btstack_crypto_wait_for_hci_result = 1; 875 hci_send_cmd(&hci_le_rand); 876 break; 877 case BTSTACK_CRYPTO_AES128: 878 btstack_crypto_aes128 = (btstack_crypto_aes128_t *) btstack_crypto; 879 #ifdef USE_BTSTACK_AES128 880 btstack_aes128_calc(btstack_crypto_aes128->key, btstack_crypto_aes128->plaintext, btstack_crypto_aes128->ciphertext); 881 btstack_crypto_done(btstack_crypto); 882 #else 883 btstack_crypto_aes128_start(btstack_crypto_aes128->key, btstack_crypto_aes128->plaintext); 884 #endif 885 break; 886 887 case BTSTACK_CRYPTO_CMAC_MESSAGE: 888 case BTSTACK_CRYPTO_CMAC_GENERATOR: 889 btstack_crypto_cmac = (btstack_crypto_aes128_cmac_t *) btstack_crypto; 890 #ifdef USE_BTSTACK_AES128 891 btstack_crypto_cmac_calc( btstack_crypto_cmac ); 892 btstack_crypto_done(btstack_crypto); 893 #else 894 btstack_crypto_wait_for_hci_result = 1; 895 if (btstack_crypto_cmac_state == CMAC_IDLE){ 896 btstack_crypto_cmac_start(btstack_crypto_cmac); 897 } else { 898 btstack_crypto_cmac_handle_aes_engine_ready(btstack_crypto_cmac); 899 } 900 #endif 901 break; 902 903 case BTSTACK_CRYPTO_CCM_DIGEST_BLOCK: 904 case BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK: 905 case BTSTACK_CRYPTO_CCM_DECRYPT_BLOCK: 906 btstack_crypto_ccm = (btstack_crypto_ccm_t *) btstack_crypto; 907 switch (btstack_crypto_ccm->state){ 908 case CCM_CALCULATE_AAD_XN: 909 #ifdef DEBUG_CCM 910 printf("CCM_CALCULATE_AAD_XN\n"); 911 #endif 912 btstack_crypto_ccm_calc_aad_xn(btstack_crypto_ccm); 913 break; 914 case CCM_CALCULATE_X1: 915 #ifdef DEBUG_CCM 916 printf("CCM_CALCULATE_X1\n"); 917 #endif 918 btstack_crypto_ccm_calc_x1(btstack_crypto_ccm); 919 break; 920 case CCM_CALCULATE_S0: 921 #ifdef DEBUG_CCM 922 printf("CCM_CALCULATE_S0\n"); 923 #endif 924 btstack_crypto_ccm_calc_s0(btstack_crypto_ccm); 925 break; 926 case CCM_CALCULATE_SN: 927 #ifdef DEBUG_CCM 928 printf("CCM_CALCULATE_SN\n"); 929 #endif 930 btstack_crypto_ccm_calc_sn(btstack_crypto_ccm); 931 break; 932 case CCM_CALCULATE_XN: 933 #ifdef DEBUG_CCM 934 printf("CCM_CALCULATE_XN\n"); 935 #endif 936 btstack_crypto_ccm_calc_xn(btstack_crypto_ccm, (btstack_crypto->operation == BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK) ? btstack_crypto_ccm->input : btstack_crypto_ccm->output); 937 break; 938 default: 939 break; 940 } 941 break; 942 943 #ifdef ENABLE_ECC_P256 944 case BTSTACK_CRYPTO_ECC_P256_GENERATE_KEY: 945 btstack_crypto_ec_p192 = (btstack_crypto_ecc_p256_t *) btstack_crypto; 946 switch (btstack_crypto_ecc_p256_key_generation_state){ 947 case ECC_P256_KEY_GENERATION_DONE: 948 // done 949 btstack_crypto_log_ec_publickey(btstack_crypto_ecc_p256_public_key); 950 (void)memcpy(btstack_crypto_ec_p192->public_key, 951 btstack_crypto_ecc_p256_public_key, 64); 952 btstack_linked_list_pop(&btstack_crypto_operations); 953 (*btstack_crypto_ec_p192->btstack_crypto.context_callback.callback)(btstack_crypto_ec_p192->btstack_crypto.context_callback.context); 954 break; 955 case ECC_P256_KEY_GENERATION_IDLE: 956 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 957 log_info("start ecc random"); 958 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_GENERATING_RANDOM; 959 btstack_crypto_ecc_p256_random_offset = 0; 960 btstack_crypto_wait_for_hci_result = 1; 961 hci_send_cmd(&hci_le_rand); 962 #else 963 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_W4_KEY; 964 btstack_crypto_wait_for_hci_result = 1; 965 hci_send_cmd(&hci_le_read_local_p256_public_key); 966 #endif 967 break; 968 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 969 case ECC_P256_KEY_GENERATION_GENERATING_RANDOM: 970 log_info("more ecc random"); 971 btstack_crypto_wait_for_hci_result = 1; 972 hci_send_cmd(&hci_le_rand); 973 break; 974 #endif 975 default: 976 break; 977 } 978 break; 979 case BTSTACK_CRYPTO_ECC_P256_CALCULATE_DHKEY: 980 btstack_crypto_ec_p192 = (btstack_crypto_ecc_p256_t *) btstack_crypto; 981 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 982 btstack_crypto_ecc_p256_calculate_dhkey_software(btstack_crypto_ec_p192); 983 // done 984 btstack_linked_list_pop(&btstack_crypto_operations); 985 (*btstack_crypto_ec_p192->btstack_crypto.context_callback.callback)(btstack_crypto_ec_p192->btstack_crypto.context_callback.context); 986 #else 987 btstack_crypto_wait_for_hci_result = 1; 988 hci_send_cmd(&hci_le_generate_dhkey, &btstack_crypto_ec_p192->public_key[0], &btstack_crypto_ec_p192->public_key[32]); 989 #endif 990 break; 991 992 #endif /* ENABLE_ECC_P256 */ 993 994 default: 995 break; 996 } 997 } 998 } 999 1000 static void btstack_crypto_handle_random_data(const uint8_t * data, uint16_t len){ 1001 btstack_crypto_random_t * btstack_crypto_random; 1002 btstack_crypto_t * btstack_crypto = (btstack_crypto_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 1003 uint16_t bytes_to_copy; 1004 if (!btstack_crypto) return; 1005 switch (btstack_crypto->operation){ 1006 case BTSTACK_CRYPTO_RANDOM: 1007 btstack_crypto_random = (btstack_crypto_random_t*) btstack_crypto; 1008 bytes_to_copy = btstack_min(btstack_crypto_random->size, len); 1009 (void)memcpy(btstack_crypto_random->buffer, data, bytes_to_copy); 1010 btstack_crypto_random->buffer += bytes_to_copy; 1011 btstack_crypto_random->size -= bytes_to_copy; 1012 // data processed, more? 1013 if (!btstack_crypto_random->size) { 1014 // done 1015 btstack_linked_list_pop(&btstack_crypto_operations); 1016 (*btstack_crypto_random->btstack_crypto.context_callback.callback)(btstack_crypto_random->btstack_crypto.context_callback.context); 1017 } 1018 break; 1019 #ifdef ENABLE_ECC_P256 1020 case BTSTACK_CRYPTO_ECC_P256_GENERATE_KEY: 1021 (void)memcpy(&btstack_crypto_ecc_p256_random[btstack_crypto_ecc_p256_random_len], 1022 data, 8); 1023 btstack_crypto_ecc_p256_random_len += 8; 1024 if (btstack_crypto_ecc_p256_random_len >= 64) { 1025 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_ACTIVE; 1026 btstack_crypto_ecc_p256_generate_key_software(); 1027 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_DONE; 1028 } 1029 break; 1030 #endif 1031 default: 1032 break; 1033 } 1034 // more work? 1035 btstack_crypto_run(); 1036 } 1037 1038 #ifndef USE_BTSTACK_AES128 1039 static void btstack_crypto_handle_encryption_result(const uint8_t * data){ 1040 btstack_crypto_aes128_t * btstack_crypto_aes128; 1041 btstack_crypto_aes128_cmac_t * btstack_crypto_cmac; 1042 btstack_crypto_ccm_t * btstack_crypto_ccm; 1043 uint8_t result[16]; 1044 1045 btstack_crypto_t * btstack_crypto = (btstack_crypto_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 1046 if (!btstack_crypto) return; 1047 switch (btstack_crypto->operation){ 1048 case BTSTACK_CRYPTO_AES128: 1049 btstack_crypto_aes128 = (btstack_crypto_aes128_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 1050 reverse_128(data, btstack_crypto_aes128->ciphertext); 1051 btstack_crypto_done(btstack_crypto); 1052 break; 1053 case BTSTACK_CRYPTO_CMAC_GENERATOR: 1054 case BTSTACK_CRYPTO_CMAC_MESSAGE: 1055 btstack_crypto_cmac = (btstack_crypto_aes128_cmac_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 1056 reverse_128(data, result); 1057 btstack_crypto_cmac_handle_encryption_result(btstack_crypto_cmac, result); 1058 break; 1059 case BTSTACK_CRYPTO_CCM_DIGEST_BLOCK: 1060 case BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK: 1061 case BTSTACK_CRYPTO_CCM_DECRYPT_BLOCK: 1062 btstack_crypto_ccm = (btstack_crypto_ccm_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 1063 switch (btstack_crypto_ccm->state){ 1064 case CCM_W4_X1: 1065 reverse_128(data, btstack_crypto_ccm->x_i); 1066 btstack_crypto_ccm_handle_x1(btstack_crypto_ccm); 1067 break; 1068 case CCM_W4_XN: 1069 reverse_128(data, btstack_crypto_ccm->x_i); 1070 btstack_crypto_ccm_handle_xn(btstack_crypto_ccm); 1071 break; 1072 case CCM_W4_AAD_XN: 1073 reverse_128(data, btstack_crypto_ccm->x_i); 1074 btstack_crypto_ccm_handle_aad_xn(btstack_crypto_ccm); 1075 break; 1076 case CCM_W4_S0: 1077 btstack_crypto_ccm_handle_s0(btstack_crypto_ccm, data); 1078 break; 1079 case CCM_W4_SN: 1080 btstack_crypto_ccm_handle_sn(btstack_crypto_ccm, data); 1081 break; 1082 default: 1083 break; 1084 } 1085 break; 1086 default: 1087 break; 1088 } 1089 } 1090 #endif 1091 1092 static void btstack_crypto_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1093 UNUSED(cid); // ok: there is no channel 1094 UNUSED(size); // ok: fixed format events read from HCI buffer 1095 1096 #ifdef ENABLE_ECC_P256 1097 #ifndef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 1098 btstack_crypto_ecc_p256_t * btstack_crypto_ec_p192; 1099 #endif 1100 #endif 1101 1102 if (packet_type != HCI_EVENT_PACKET) return; 1103 1104 switch (hci_event_packet_get_type(packet)){ 1105 case BTSTACK_EVENT_STATE: 1106 log_info("BTSTACK_EVENT_STATE"); 1107 if (btstack_event_state_get_state(packet) != HCI_STATE_HALTING) break; 1108 if (!btstack_crypto_wait_for_hci_result) break; 1109 // request stack to defer shutdown a bit 1110 hci_halting_defer(); 1111 break; 1112 1113 case HCI_EVENT_COMMAND_COMPLETE: 1114 #ifndef USE_BTSTACK_AES128 1115 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 1116 if (!btstack_crypto_wait_for_hci_result) return; 1117 btstack_crypto_wait_for_hci_result = 0; 1118 btstack_crypto_handle_encryption_result(&packet[6]); 1119 } 1120 #endif 1121 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 1122 if (!btstack_crypto_wait_for_hci_result) return; 1123 btstack_crypto_wait_for_hci_result = 0; 1124 btstack_crypto_handle_random_data(&packet[6], 8); 1125 } 1126 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_local_supported_commands)){ 1127 int ecdh_operations_supported = (packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+34] & 0x06) == 0x06; 1128 UNUSED(ecdh_operations_supported); 1129 log_info("controller supports ECDH operation: %u", ecdh_operations_supported); 1130 #ifdef ENABLE_ECC_P256 1131 #ifndef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 1132 if (!ecdh_operations_supported){ 1133 // mbedTLS can also be used if already available (and malloc is supported) 1134 log_error("ECC-P256 support enabled, but HCI Controller doesn't support it. Please add ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS to btstack_config.h"); 1135 } 1136 #endif 1137 #endif 1138 } 1139 break; 1140 1141 #ifdef ENABLE_ECC_P256 1142 #ifndef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 1143 case HCI_EVENT_LE_META: 1144 btstack_crypto_ec_p192 = (btstack_crypto_ecc_p256_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 1145 if (!btstack_crypto_ec_p192) break; 1146 switch (hci_event_le_meta_get_subevent_code(packet)){ 1147 case HCI_SUBEVENT_LE_READ_LOCAL_P256_PUBLIC_KEY_COMPLETE: 1148 if (btstack_crypto_ec_p192->btstack_crypto.operation != BTSTACK_CRYPTO_ECC_P256_GENERATE_KEY) break; 1149 if (!btstack_crypto_wait_for_hci_result) return; 1150 btstack_crypto_wait_for_hci_result = 0; 1151 if (hci_subevent_le_read_local_p256_public_key_complete_get_status(packet)){ 1152 log_error("Read Local P256 Public Key failed"); 1153 } 1154 hci_subevent_le_read_local_p256_public_key_complete_get_dhkey_x(packet, &btstack_crypto_ecc_p256_public_key[0]); 1155 hci_subevent_le_read_local_p256_public_key_complete_get_dhkey_y(packet, &btstack_crypto_ecc_p256_public_key[32]); 1156 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_DONE; 1157 break; 1158 case HCI_SUBEVENT_LE_GENERATE_DHKEY_COMPLETE: 1159 if (btstack_crypto_ec_p192->btstack_crypto.operation != BTSTACK_CRYPTO_ECC_P256_CALCULATE_DHKEY) break; 1160 if (!btstack_crypto_wait_for_hci_result) return; 1161 btstack_crypto_wait_for_hci_result = 0; 1162 if (hci_subevent_le_generate_dhkey_complete_get_status(packet)){ 1163 log_error("Generate DHKEY failed -> abort"); 1164 } 1165 hci_subevent_le_generate_dhkey_complete_get_dhkey(packet, btstack_crypto_ec_p192->dhkey); 1166 // done 1167 btstack_linked_list_pop(&btstack_crypto_operations); 1168 (*btstack_crypto_ec_p192->btstack_crypto.context_callback.callback)(btstack_crypto_ec_p192->btstack_crypto.context_callback.context); 1169 break; 1170 default: 1171 break; 1172 } 1173 break; 1174 #endif 1175 #endif 1176 default: 1177 break; 1178 } 1179 1180 // try processing 1181 btstack_crypto_run(); 1182 } 1183 1184 void btstack_crypto_init(void){ 1185 if (btstack_crypto_initialized) return; 1186 btstack_crypto_initialized = 1; 1187 1188 // register with HCI 1189 hci_event_callback_registration.callback = &btstack_crypto_event_handler; 1190 hci_add_event_handler(&hci_event_callback_registration); 1191 1192 #ifdef USE_MBEDTLS_ECC_P256 1193 mbedtls_ecp_group_init(&mbedtls_ec_group); 1194 mbedtls_ecp_group_load(&mbedtls_ec_group, MBEDTLS_ECP_DP_SECP256R1); 1195 #endif 1196 } 1197 1198 void btstack_crypto_random_generate(btstack_crypto_random_t * request, uint8_t * buffer, uint16_t size, void (* callback)(void * arg), void * callback_arg){ 1199 request->btstack_crypto.context_callback.callback = callback; 1200 request->btstack_crypto.context_callback.context = callback_arg; 1201 request->btstack_crypto.operation = BTSTACK_CRYPTO_RANDOM; 1202 request->buffer = buffer; 1203 request->size = size; 1204 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1205 btstack_crypto_run(); 1206 } 1207 1208 void btstack_crypto_aes128_encrypt(btstack_crypto_aes128_t * request, const uint8_t * key, const uint8_t * plaintext, uint8_t * ciphertext, void (* callback)(void * arg), void * callback_arg){ 1209 request->btstack_crypto.context_callback.callback = callback; 1210 request->btstack_crypto.context_callback.context = callback_arg; 1211 request->btstack_crypto.operation = BTSTACK_CRYPTO_AES128; 1212 request->key = key; 1213 request->plaintext = plaintext; 1214 request->ciphertext = ciphertext; 1215 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1216 btstack_crypto_run(); 1217 } 1218 1219 void btstack_crypto_aes128_cmac_generator(btstack_crypto_aes128_cmac_t * request, const uint8_t * key, uint16_t size, uint8_t (*get_byte_callback)(uint16_t pos), uint8_t * hash, void (* callback)(void * arg), void * callback_arg){ 1220 request->btstack_crypto.context_callback.callback = callback; 1221 request->btstack_crypto.context_callback.context = callback_arg; 1222 request->btstack_crypto.operation = BTSTACK_CRYPTO_CMAC_GENERATOR; 1223 request->key = key; 1224 request->size = size; 1225 request->data.get_byte_callback = get_byte_callback; 1226 request->hash = hash; 1227 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1228 btstack_crypto_run(); 1229 } 1230 1231 void btstack_crypto_aes128_cmac_message(btstack_crypto_aes128_cmac_t * request, const uint8_t * key, uint16_t size, const uint8_t * message, uint8_t * hash, void (* callback)(void * arg), void * callback_arg){ 1232 request->btstack_crypto.context_callback.callback = callback; 1233 request->btstack_crypto.context_callback.context = callback_arg; 1234 request->btstack_crypto.operation = BTSTACK_CRYPTO_CMAC_MESSAGE; 1235 request->key = key; 1236 request->size = size; 1237 request->data.message = message; 1238 request->hash = hash; 1239 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1240 btstack_crypto_run(); 1241 } 1242 1243 void btstack_crypto_aes128_cmac_zero(btstack_crypto_aes128_cmac_t * request, uint16_t len, const uint8_t * message, uint8_t * hash, void (* callback)(void * arg), void * callback_arg){ 1244 request->btstack_crypto.context_callback.callback = callback; 1245 request->btstack_crypto.context_callback.context = callback_arg; 1246 request->btstack_crypto.operation = BTSTACK_CRYPTO_CMAC_MESSAGE; 1247 request->key = zero; 1248 request->size = len; 1249 request->data.message = message; 1250 request->hash = hash; 1251 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1252 btstack_crypto_run(); 1253 } 1254 1255 #ifdef ENABLE_ECC_P256 1256 void btstack_crypto_ecc_p256_generate_key(btstack_crypto_ecc_p256_t * request, uint8_t * public_key, void (* callback)(void * arg), void * callback_arg){ 1257 // reset key generation 1258 if (btstack_crypto_ecc_p256_key_generation_state == ECC_P256_KEY_GENERATION_DONE){ 1259 btstack_crypto_ecc_p256_random_len = 0; 1260 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_IDLE; 1261 } 1262 request->btstack_crypto.context_callback.callback = callback; 1263 request->btstack_crypto.context_callback.context = callback_arg; 1264 request->btstack_crypto.operation = BTSTACK_CRYPTO_ECC_P256_GENERATE_KEY; 1265 request->public_key = public_key; 1266 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1267 btstack_crypto_run(); 1268 } 1269 1270 void btstack_crypto_ecc_p256_calculate_dhkey(btstack_crypto_ecc_p256_t * request, const uint8_t * public_key, uint8_t * dhkey, void (* callback)(void * arg), void * callback_arg){ 1271 request->btstack_crypto.context_callback.callback = callback; 1272 request->btstack_crypto.context_callback.context = callback_arg; 1273 request->btstack_crypto.operation = BTSTACK_CRYPTO_ECC_P256_CALCULATE_DHKEY; 1274 request->public_key = (uint8_t *) public_key; 1275 request->dhkey = dhkey; 1276 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1277 btstack_crypto_run(); 1278 } 1279 1280 int btstack_crypto_ecc_p256_validate_public_key(const uint8_t * public_key){ 1281 1282 // validate public key using micro-ecc 1283 int err = 0; 1284 1285 #ifdef USE_MICRO_ECC_P256 1286 #if uECC_SUPPORTS_secp256r1 1287 // standard version 1288 err = uECC_valid_public_key(public_key, uECC_secp256r1()) == 0; 1289 #else 1290 // static version 1291 err = uECC_valid_public_key(public_key) == 0; 1292 #endif 1293 #endif 1294 1295 #ifdef USE_MBEDTLS_ECC_P256 1296 mbedtls_ecp_point Q; 1297 mbedtls_ecp_point_init( &Q ); 1298 mbedtls_mpi_read_binary(&Q.X, &public_key[0], 32); 1299 mbedtls_mpi_read_binary(&Q.Y, &public_key[32], 32); 1300 mbedtls_mpi_lset(&Q.Z, 1); 1301 err = mbedtls_ecp_check_pubkey(&mbedtls_ec_group, &Q); 1302 mbedtls_ecp_point_free( & Q); 1303 #endif 1304 1305 if (err){ 1306 log_error("public key invalid %x", err); 1307 } 1308 return err; 1309 } 1310 #endif 1311 1312 void btstack_crypto_ccm_init(btstack_crypto_ccm_t * request, const uint8_t * key, const uint8_t * nonce, uint16_t message_len, uint16_t additional_authenticated_data_len, uint8_t auth_len){ 1313 request->key = key; 1314 request->nonce = nonce; 1315 request->message_len = message_len; 1316 request->aad_len = additional_authenticated_data_len; 1317 request->aad_offset = 0; 1318 request->auth_len = auth_len; 1319 request->counter = 1; 1320 request->state = CCM_CALCULATE_X1; 1321 } 1322 1323 void btstack_crypto_ccm_digest(btstack_crypto_ccm_t * request, uint8_t * additional_authenticated_data, uint16_t additional_authenticated_data_len, void (* callback)(void * arg), void * callback_arg){ 1324 // not implemented yet 1325 request->btstack_crypto.context_callback.callback = callback; 1326 request->btstack_crypto.context_callback.context = callback_arg; 1327 request->btstack_crypto.operation = BTSTACK_CRYPTO_CCM_DIGEST_BLOCK; 1328 request->block_len = additional_authenticated_data_len; 1329 request->input = additional_authenticated_data; 1330 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1331 btstack_crypto_run(); 1332 } 1333 1334 void btstack_crypto_ccm_get_authentication_value(btstack_crypto_ccm_t * request, uint8_t * authentication_value){ 1335 (void)memcpy(authentication_value, request->x_i, request->auth_len); 1336 } 1337 1338 void btstack_crypto_ccm_encrypt_block(btstack_crypto_ccm_t * request, uint16_t block_len, const uint8_t * plaintext, uint8_t * ciphertext, void (* callback)(void * arg), void * callback_arg){ 1339 #ifdef DEBUG_CCM 1340 printf("\nbtstack_crypto_ccm_encrypt_block, len %u\n", block_len); 1341 #endif 1342 request->btstack_crypto.context_callback.callback = callback; 1343 request->btstack_crypto.context_callback.context = callback_arg; 1344 request->btstack_crypto.operation = BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK; 1345 request->block_len = block_len; 1346 request->input = plaintext; 1347 request->output = ciphertext; 1348 if (request->state != CCM_CALCULATE_X1){ 1349 request->state = CCM_CALCULATE_XN; 1350 } 1351 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1352 btstack_crypto_run(); 1353 } 1354 1355 void btstack_crypto_ccm_decrypt_block(btstack_crypto_ccm_t * request, uint16_t block_len, const uint8_t * ciphertext, uint8_t * plaintext, void (* callback)(void * arg), void * callback_arg){ 1356 request->btstack_crypto.context_callback.callback = callback; 1357 request->btstack_crypto.context_callback.context = callback_arg; 1358 request->btstack_crypto.operation = BTSTACK_CRYPTO_CCM_DECRYPT_BLOCK; 1359 request->block_len = block_len; 1360 request->input = ciphertext; 1361 request->output = plaintext; 1362 if (request->state != CCM_CALCULATE_X1){ 1363 request->state = CCM_CALCULATE_SN; 1364 } 1365 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1366 btstack_crypto_run(); 1367 } 1368 1369 // PTS only 1370 void btstack_crypto_ecc_p256_set_key(const uint8_t * public_key, const uint8_t * private_key){ 1371 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 1372 (void)memcpy(btstack_crypto_ecc_p256_d, private_key, 32); 1373 (void)memcpy(btstack_crypto_ecc_p256_public_key, public_key, 64); 1374 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_DONE; 1375 #else 1376 UNUSED(public_key); 1377 UNUSED(private_key); 1378 #endif 1379 } 1380 // Unit testing 1381 int btstack_crypto_idle(void){ 1382 return btstack_linked_list_empty(&btstack_crypto_operations); 1383 } 1384 void btstack_crypto_reset(void){ 1385 btstack_crypto_operations = NULL; 1386 btstack_crypto_wait_for_hci_result = 0; 1387 } 1388