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 "btstack_bool.h" 48 #include "hci.h" 49 50 // 51 // AES128 Configuration 52 // 53 54 // By default, AES128 is computed by Bluetooth Controller using HCI Command/Event asynchronously 55 // as fallback/alternative, a software implementation can be used 56 // configure ECC implementations 57 #if defined(HAVE_AES128) && defined(ENABLE_SOFTWARE_AES128) 58 #error "If you have custom AES128 implementation (HAVE_AES128), please disable software AES128 (ENABLE_SOFTWARE_AES128) in bstack_config.h" 59 #endif 60 61 #ifdef ENABLE_SOFTWARE_AES128 62 #define HAVE_AES128 63 #include "rijndael.h" 64 #endif 65 66 #ifdef HAVE_AES128 67 #define USE_BTSTACK_AES128 68 #endif 69 70 // 71 // ECC Configuration 72 // 73 74 // backwards-compatitility ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS -> ENABLE_MICRO_ECC_P256 75 #if defined(ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS) && !defined(ENABLE_MICRO_ECC_P256) 76 #define ENABLE_MICRO_ECC_P256 77 #endif 78 79 // configure ECC implementations 80 #if defined(ENABLE_MICRO_ECC_P256) && defined(HAVE_MBEDTLS_ECC_P256) 81 #error "If you have mbedTLS (HAVE_MBEDTLS_ECC_P256), please disable uECC (ENABLE_MICRO_ECC_P256) in bstack_config.h" 82 #endif 83 84 // Software ECC-P256 implementation provided by micro-ecc 85 #ifdef ENABLE_MICRO_ECC_P256 86 #define ENABLE_ECC_P256 87 #define USE_MICRO_ECC_P256 88 #define USE_SOFTWARE_ECC_P256_IMPLEMENTATION 89 #include "uECC.h" 90 #endif 91 92 // Software ECC-P256 implementation provided by mbedTLS 93 #ifdef HAVE_MBEDTLS_ECC_P256 94 #define ENABLE_ECC_P256 95 #define USE_MBEDTLS_ECC_P256 96 #define USE_SOFTWARE_ECC_P256_IMPLEMENTATION 97 #include "mbedtls/config.h" 98 #include "mbedtls/platform.h" 99 #include "mbedtls/ecp.h" 100 #endif 101 102 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(ENABLE_ECC_P256) 103 #define ENABLE_ECC_P256 104 #endif 105 106 // debugging 107 // #define DEBUG_CCM 108 109 typedef enum { 110 CMAC_IDLE, 111 CMAC_CALC_SUBKEYS, 112 CMAC_W4_SUBKEYS, 113 CMAC_CALC_MI, 114 CMAC_W4_MI, 115 CMAC_CALC_MLAST, 116 CMAC_W4_MLAST 117 } btstack_crypto_cmac_state_t; 118 119 typedef enum { 120 ECC_P256_KEY_GENERATION_IDLE, 121 ECC_P256_KEY_GENERATION_GENERATING_RANDOM, 122 ECC_P256_KEY_GENERATION_ACTIVE, 123 ECC_P256_KEY_GENERATION_W4_KEY, 124 ECC_P256_KEY_GENERATION_DONE, 125 } btstack_crypto_ecc_p256_key_generation_state_t; 126 127 static void btstack_crypto_run(void); 128 129 static const uint8_t zero[16] = { 0 }; 130 131 static bool btstack_crypto_initialized; 132 static bool btstack_crypto_wait_for_hci_result; 133 static btstack_linked_list_t btstack_crypto_operations; 134 static btstack_packet_callback_registration_t hci_event_callback_registration; 135 136 // state for AES-CMAC 137 #ifndef USE_BTSTACK_AES128 138 static btstack_crypto_cmac_state_t btstack_crypto_cmac_state; 139 static sm_key_t btstack_crypto_cmac_k; 140 static sm_key_t btstack_crypto_cmac_x; 141 static sm_key_t btstack_crypto_cmac_subkey; 142 static uint8_t btstack_crypto_cmac_block_current; 143 static uint8_t btstack_crypto_cmac_block_count; 144 #endif 145 146 // state for AES-CCM 147 static uint8_t btstack_crypto_ccm_s[16]; 148 149 #ifdef ENABLE_ECC_P256 150 151 static uint8_t btstack_crypto_ecc_p256_public_key[64]; 152 static uint8_t btstack_crypto_ecc_p256_random[64]; 153 static uint8_t btstack_crypto_ecc_p256_random_len; 154 static uint8_t btstack_crypto_ecc_p256_random_offset; 155 static btstack_crypto_ecc_p256_key_generation_state_t btstack_crypto_ecc_p256_key_generation_state; 156 157 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 158 static uint8_t btstack_crypto_ecc_p256_d[32]; 159 #endif 160 161 // Software ECDH implementation provided by mbedtls 162 #ifdef USE_MBEDTLS_ECC_P256 163 static mbedtls_ecp_group mbedtls_ec_group; 164 #endif 165 166 #endif /* ENABLE_ECC_P256 */ 167 168 #ifdef ENABLE_SOFTWARE_AES128 169 // AES128 using public domain rijndael implementation 170 void btstack_aes128_calc(const uint8_t * key, const uint8_t * plaintext, uint8_t * ciphertext){ 171 uint32_t rk[RKLENGTH(KEYBITS)]; 172 int nrounds = rijndaelSetupEncrypt(rk, &key[0], KEYBITS); 173 rijndaelEncrypt(rk, nrounds, plaintext, ciphertext); 174 } 175 #endif 176 177 static void btstack_crypto_done(btstack_crypto_t * btstack_crypto){ 178 btstack_linked_list_pop(&btstack_crypto_operations); 179 (*btstack_crypto->context_callback.callback)(btstack_crypto->context_callback.context); 180 } 181 182 static void btstack_crypto_cmac_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 183 int i; 184 int carry = 0; 185 for (i=len-1; i >= 0 ; i--){ 186 int new_carry = data[i] >> 7; 187 data[i] = (data[i] << 1) | carry; 188 carry = new_carry; 189 } 190 } 191 192 static uint8_t btstack_crypto_cmac_get_byte(btstack_crypto_aes128_cmac_t * btstack_crypto_cmac, uint16_t pos){ 193 if (btstack_crypto_cmac->btstack_crypto.operation == BTSTACK_CRYPTO_CMAC_GENERATOR){ 194 return (*btstack_crypto_cmac->data.get_byte_callback)(pos); 195 } else { 196 return btstack_crypto_cmac->data.message[pos]; 197 } 198 } 199 200 #ifdef USE_BTSTACK_AES128 201 202 static void btstack_crypto_cmac_calc_subkeys(sm_key_t k0, sm_key_t k1, sm_key_t k2){ 203 memcpy(k1, k0, 16); 204 btstack_crypto_cmac_shift_left_by_one_bit_inplace(16, k1); 205 if (k0[0] & 0x80){ 206 k1[15] ^= 0x87; 207 } 208 memcpy(k2, k1, 16); 209 btstack_crypto_cmac_shift_left_by_one_bit_inplace(16, k2); 210 if (k1[0] & 0x80){ 211 k2[15] ^= 0x87; 212 } 213 } 214 215 static void btstack_crypto_cmac_calc(btstack_crypto_aes128_cmac_t * btstack_crypto_cmac) { 216 sm_key_t k0, k1, k2; 217 uint16_t i; 218 219 btstack_aes128_calc(btstack_crypto_cmac->key, zero, k0); 220 btstack_crypto_cmac_calc_subkeys(k0, k1, k2); 221 222 uint16_t cmac_block_count = (btstack_crypto_cmac->size + 15) / 16; 223 224 // step 3: .. 225 if (cmac_block_count==0){ 226 cmac_block_count = 1; 227 } 228 229 // Step 5 230 sm_key_t cmac_x; 231 memset(cmac_x, 0, 16); 232 233 // Step 6 234 sm_key_t cmac_y; 235 int block; 236 for (block = 0 ; block < cmac_block_count-1 ; block++){ 237 for (i=0;i<16;i++){ 238 cmac_y[i] = cmac_x[i] ^ btstack_crypto_cmac_get_byte(btstack_crypto_cmac, (block*16) + i); 239 } 240 btstack_aes128_calc(btstack_crypto_cmac->key, cmac_y, cmac_x); 241 } 242 243 // step 4: set m_last 244 sm_key_t cmac_m_last; 245 bool last_block_complete = btstack_crypto_cmac->size != 0 && (btstack_crypto_cmac->size & 0x0f) == 0; 246 if (last_block_complete){ 247 for (i=0;i<16;i++){ 248 cmac_m_last[i] = btstack_crypto_cmac_get_byte(btstack_crypto_cmac, btstack_crypto_cmac->size - 16 + i) ^ k1[i]; 249 } 250 } else { 251 uint16_t valid_octets_in_last_block = btstack_crypto_cmac->size & 0x0f; 252 for (i=0;i<16;i++){ 253 if (i < valid_octets_in_last_block){ 254 cmac_m_last[i] = btstack_crypto_cmac_get_byte(btstack_crypto_cmac, (btstack_crypto_cmac->size & 0xfff0) + i) ^ k2[i]; 255 continue; 256 } 257 if (i == valid_octets_in_last_block){ 258 cmac_m_last[i] = 0x80 ^ k2[i]; 259 continue; 260 } 261 cmac_m_last[i] = k2[i]; 262 } 263 } 264 265 for (i=0;i<16;i++){ 266 cmac_y[i] = cmac_x[i] ^ cmac_m_last[i]; 267 } 268 269 // Step 7 270 btstack_aes128_calc(btstack_crypto_cmac->key, cmac_y, btstack_crypto_cmac->hash); 271 } 272 #else 273 274 static void btstack_crypto_aes128_start(const sm_key_t key, const sm_key_t plaintext){ 275 uint8_t key_flipped[16]; 276 uint8_t plaintext_flipped[16]; 277 reverse_128(key, key_flipped); 278 reverse_128(plaintext, plaintext_flipped); 279 btstack_crypto_wait_for_hci_result = 1; 280 hci_send_cmd(&hci_le_encrypt, key_flipped, plaintext_flipped); 281 } 282 283 static inline void btstack_crypto_cmac_next_state(void){ 284 btstack_crypto_cmac_state = (btstack_crypto_cmac_state_t) (((int)btstack_crypto_cmac_state) + 1); 285 } 286 287 static int btstack_crypto_cmac_last_block_complete(btstack_crypto_aes128_cmac_t * btstack_crypto_cmac){ 288 uint16_t len = btstack_crypto_cmac->size; 289 if (len == 0u) return 0u; 290 return (len & 0x0fu) == 0u; 291 } 292 293 static void btstack_crypto_cmac_handle_aes_engine_ready(btstack_crypto_aes128_cmac_t * btstack_crypto_cmac){ 294 switch (btstack_crypto_cmac_state){ 295 case CMAC_CALC_SUBKEYS: { 296 btstack_crypto_cmac_next_state(); 297 btstack_crypto_aes128_start(btstack_crypto_cmac_k, zero); 298 break; 299 } 300 case CMAC_CALC_MI: { 301 int j; 302 sm_key_t y; 303 for (j=0;j<16;j++){ 304 y[j] = btstack_crypto_cmac_x[j] ^ btstack_crypto_cmac_get_byte(btstack_crypto_cmac, (btstack_crypto_cmac_block_current*16u) + j); 305 } 306 btstack_crypto_cmac_block_current++; 307 btstack_crypto_cmac_next_state(); 308 btstack_crypto_aes128_start(btstack_crypto_cmac_k, y); 309 break; 310 } 311 case CMAC_CALC_MLAST: { 312 sm_key_t k1; 313 (void)memcpy(k1, btstack_crypto_cmac_subkey, 16); 314 btstack_crypto_cmac_shift_left_by_one_bit_inplace(16, k1); 315 if (btstack_crypto_cmac_subkey[0u] & 0x80u){ 316 k1[15u] ^= 0x87u; 317 } 318 sm_key_t k2; 319 (void)memcpy(k2, k1, 16); 320 btstack_crypto_cmac_shift_left_by_one_bit_inplace(16, k2); 321 if (k1[0u] & 0x80u){ 322 k2[15u] ^= 0x87u; 323 } 324 325 log_info_key("k", btstack_crypto_cmac_k); 326 log_info_key("k1", k1); 327 log_info_key("k2", k2); 328 329 // step 4: set m_last 330 int i; 331 sm_key_t btstack_crypto_cmac_m_last; 332 if (btstack_crypto_cmac_last_block_complete(btstack_crypto_cmac)){ 333 for (i=0;i<16;i++){ 334 btstack_crypto_cmac_m_last[i] = btstack_crypto_cmac_get_byte(btstack_crypto_cmac, btstack_crypto_cmac->size - 16u + i) ^ k1[i]; 335 } 336 } else { 337 int valid_octets_in_last_block = btstack_crypto_cmac->size & 0x0fu; 338 for (i=0;i<16;i++){ 339 if (i < valid_octets_in_last_block){ 340 btstack_crypto_cmac_m_last[i] = btstack_crypto_cmac_get_byte(btstack_crypto_cmac, (btstack_crypto_cmac->size & 0xfff0u) + i) ^ k2[i]; 341 continue; 342 } 343 if (i == valid_octets_in_last_block){ 344 btstack_crypto_cmac_m_last[i] = 0x80u ^ k2[i]; 345 continue; 346 } 347 btstack_crypto_cmac_m_last[i] = k2[i]; 348 } 349 } 350 sm_key_t y; 351 for (i=0;i<16;i++){ 352 y[i] = btstack_crypto_cmac_x[i] ^ btstack_crypto_cmac_m_last[i]; 353 } 354 btstack_crypto_cmac_block_current++; 355 btstack_crypto_cmac_next_state(); 356 btstack_crypto_aes128_start(btstack_crypto_cmac_k, y); 357 break; 358 } 359 default: 360 log_info("btstack_crypto_cmac_handle_aes_engine_ready called in state %u", btstack_crypto_cmac_state); 361 break; 362 } 363 } 364 365 static void btstack_crypto_cmac_handle_encryption_result(btstack_crypto_aes128_cmac_t * btstack_crypto_cmac, sm_key_t data){ 366 switch (btstack_crypto_cmac_state){ 367 case CMAC_W4_SUBKEYS: 368 (void)memcpy(btstack_crypto_cmac_subkey, data, 16); 369 // next 370 btstack_crypto_cmac_state = (btstack_crypto_cmac_block_current < (btstack_crypto_cmac_block_count - 1u)) ? CMAC_CALC_MI : CMAC_CALC_MLAST; 371 break; 372 case CMAC_W4_MI: 373 (void)memcpy(btstack_crypto_cmac_x, data, 16); 374 btstack_crypto_cmac_state = (btstack_crypto_cmac_block_current < (btstack_crypto_cmac_block_count - 1u)) ? CMAC_CALC_MI : CMAC_CALC_MLAST; 375 break; 376 case CMAC_W4_MLAST: 377 // done 378 log_info("Setting CMAC Engine to IDLE"); 379 btstack_crypto_cmac_state = CMAC_IDLE; 380 log_info_key("CMAC", data); 381 (void)memcpy(btstack_crypto_cmac->hash, data, 16); 382 btstack_linked_list_pop(&btstack_crypto_operations); 383 (*btstack_crypto_cmac->btstack_crypto.context_callback.callback)(btstack_crypto_cmac->btstack_crypto.context_callback.context); 384 break; 385 default: 386 log_info("btstack_crypto_cmac_handle_encryption_result called in state %u", btstack_crypto_cmac_state); 387 break; 388 } 389 } 390 391 static void btstack_crypto_cmac_start(btstack_crypto_aes128_cmac_t * btstack_crypto_cmac){ 392 393 (void)memcpy(btstack_crypto_cmac_k, btstack_crypto_cmac->key, 16); 394 memset(btstack_crypto_cmac_x, 0, 16); 395 btstack_crypto_cmac_block_current = 0; 396 397 // step 2: n := ceil(len/const_Bsize); 398 btstack_crypto_cmac_block_count = (btstack_crypto_cmac->size + 15u) / 16u; 399 400 // step 3: .. 401 if (btstack_crypto_cmac_block_count==0u){ 402 btstack_crypto_cmac_block_count = 1; 403 } 404 log_info("btstack_crypto_cmac_start: len %u, block count %u", btstack_crypto_cmac->size, btstack_crypto_cmac_block_count); 405 406 // first, we need to compute l for k1, k2, and m_last 407 btstack_crypto_cmac_state = CMAC_CALC_SUBKEYS; 408 409 // let's go 410 btstack_crypto_cmac_handle_aes_engine_ready(btstack_crypto_cmac); 411 } 412 #endif 413 414 /* 415 To encrypt the message data we use Counter (CTR) mode. We first 416 define the key stream blocks by: 417 418 S_i := E( K, A_i ) for i=0, 1, 2, ... 419 420 The values A_i are formatted as follows, where the Counter field i is 421 encoded in most-significant-byte first order: 422 423 Octet Number Contents 424 ------------ --------- 425 0 Flags 426 1 ... 15-L Nonce N 427 16-L ... 15 Counter i 428 429 Bit Number Contents 430 ---------- ---------------------- 431 7 Reserved (always zero) 432 6 Reserved (always zero) 433 5 ... 3 Zero 434 2 ... 0 L' 435 */ 436 437 static void btstack_crypto_ccm_setup_a_i(btstack_crypto_ccm_t * btstack_crypto_ccm, uint16_t counter){ 438 btstack_crypto_ccm_s[0] = 1; // L' = L - 1 439 (void)memcpy(&btstack_crypto_ccm_s[1], btstack_crypto_ccm->nonce, 13); 440 big_endian_store_16(btstack_crypto_ccm_s, 14, counter); 441 #ifdef DEBUG_CCM 442 printf("btstack_crypto_ccm_setup_a_%u\n", counter); 443 printf("%16s: ", "ai"); 444 printf_hexdump(btstack_crypto_ccm_s, 16); 445 #endif 446 } 447 448 /* 449 The first step is to compute the authentication field T. This is 450 done using CBC-MAC [MAC]. We first define a sequence of blocks B_0, 451 B_1, ..., B_n and then apply CBC-MAC to these blocks. 452 453 The first block B_0 is formatted as follows, where l(m) is encoded in 454 most-significant-byte first order: 455 456 Octet Number Contents 457 ------------ --------- 458 0 Flags 459 1 ... 15-L Nonce N 460 16-L ... 15 l(m) 461 462 Within the first block B_0, the Flags field is formatted as follows: 463 464 Bit Number Contents 465 ---------- ---------------------- 466 7 Reserved (always zero) 467 6 Adata 468 5 ... 3 M' 469 2 ... 0 L' 470 */ 471 472 static void btstack_crypto_ccm_setup_b_0(btstack_crypto_ccm_t * btstack_crypto_ccm, uint8_t * b0){ 473 uint8_t m_prime = (btstack_crypto_ccm->auth_len - 2u) / 2u; 474 uint8_t Adata = btstack_crypto_ccm->aad_len ? 1 : 0; 475 b0[0u] = (Adata << 6u) | (m_prime << 3u) | 1u ; // Adata, M', L' = L - 1 476 (void)memcpy(&b0[1], btstack_crypto_ccm->nonce, 13); 477 big_endian_store_16(b0, 14, btstack_crypto_ccm->message_len); 478 #ifdef DEBUG_CCM 479 printf("%16s: ", "B0"); 480 printf_hexdump(b0, 16); 481 #endif 482 } 483 484 #ifdef ENABLE_ECC_P256 485 486 static void btstack_crypto_log_ec_publickey(const uint8_t * ec_q){ 487 log_info("Elliptic curve: X"); 488 log_info_hexdump(&ec_q[0],32); 489 log_info("Elliptic curve: Y"); 490 log_info_hexdump(&ec_q[32],32); 491 } 492 493 #if (defined(USE_MICRO_ECC_P256) && !defined(WICED_VERSION)) || defined(USE_MBEDTLS_ECC_P256) 494 // @return OK 495 static int sm_generate_f_rng(unsigned char * buffer, unsigned size){ 496 if (btstack_crypto_ecc_p256_key_generation_state != ECC_P256_KEY_GENERATION_ACTIVE) return 0; 497 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, btstack_crypto_ecc_p256_random_offset); 498 while (size) { 499 *buffer++ = btstack_crypto_ecc_p256_random[btstack_crypto_ecc_p256_random_offset++]; 500 size--; 501 } 502 return 1; 503 } 504 #endif 505 #ifdef USE_MBEDTLS_ECC_P256 506 // @return error - just wrap sm_generate_f_rng 507 static int sm_generate_f_rng_mbedtls(void * context, unsigned char * buffer, size_t size){ 508 UNUSED(context); 509 return sm_generate_f_rng(buffer, size) == 0; 510 } 511 #endif /* USE_MBEDTLS_ECC_P256 */ 512 513 static void btstack_crypto_ecc_p256_generate_key_software(void){ 514 515 btstack_crypto_ecc_p256_random_offset = 0; 516 517 // generate EC key 518 #ifdef USE_MICRO_ECC_P256 519 520 #ifndef WICED_VERSION 521 log_info("set uECC RNG for initial key generation with 64 random bytes"); 522 // micro-ecc from WICED SDK uses its wiced_crypto_get_random by default - no need to set it 523 uECC_set_rng(&sm_generate_f_rng); 524 #endif /* WICED_VERSION */ 525 526 #if uECC_SUPPORTS_secp256r1 527 // standard version 528 uECC_make_key(btstack_crypto_ecc_p256_public_key, btstack_crypto_ecc_p256_d, uECC_secp256r1()); 529 530 // disable RNG again, as returning no randmon data lets shared key generation fail 531 log_info("disable uECC RNG in standard version after key generation"); 532 uECC_set_rng(NULL); 533 #else 534 // static version 535 uECC_make_key(btstack_crypto_ecc_p256_public_key, btstack_crypto_ecc_p256_d); 536 #endif 537 #endif /* USE_MICRO_ECC_P256 */ 538 539 #ifdef USE_MBEDTLS_ECC_P256 540 mbedtls_mpi d; 541 mbedtls_ecp_point P; 542 mbedtls_mpi_init(&d); 543 mbedtls_ecp_point_init(&P); 544 int res = mbedtls_ecp_gen_keypair(&mbedtls_ec_group, &d, &P, &sm_generate_f_rng_mbedtls, NULL); 545 log_info("gen keypair %x", res); 546 mbedtls_mpi_write_binary(&P.X, &btstack_crypto_ecc_p256_public_key[0], 32); 547 mbedtls_mpi_write_binary(&P.Y, &btstack_crypto_ecc_p256_public_key[32], 32); 548 mbedtls_mpi_write_binary(&d, btstack_crypto_ecc_p256_d, 32); 549 mbedtls_ecp_point_free(&P); 550 mbedtls_mpi_free(&d); 551 #endif /* USE_MBEDTLS_ECC_P256 */ 552 } 553 554 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 555 static void btstack_crypto_ecc_p256_calculate_dhkey_software(btstack_crypto_ecc_p256_t * btstack_crypto_ec_p192){ 556 memset(btstack_crypto_ec_p192->dhkey, 0, 32); 557 558 #ifdef USE_MICRO_ECC_P256 559 #if uECC_SUPPORTS_secp256r1 560 // standard version 561 uECC_shared_secret(btstack_crypto_ec_p192->public_key, btstack_crypto_ecc_p256_d, btstack_crypto_ec_p192->dhkey, uECC_secp256r1()); 562 #else 563 // static version 564 uECC_shared_secret(btstack_crypto_ec_p192->public_key, btstack_crypto_ecc_p256_d, btstack_crypto_ec_p192->dhkey); 565 #endif 566 #endif 567 568 #ifdef USE_MBEDTLS_ECC_P256 569 // da * Pb 570 mbedtls_mpi d; 571 mbedtls_ecp_point Q; 572 mbedtls_ecp_point DH; 573 mbedtls_mpi_init(&d); 574 mbedtls_ecp_point_init(&Q); 575 mbedtls_ecp_point_init(&DH); 576 mbedtls_mpi_read_binary(&d, btstack_crypto_ecc_p256_d, 32); 577 mbedtls_mpi_read_binary(&Q.X, &btstack_crypto_ec_p192->public_key[0] , 32); 578 mbedtls_mpi_read_binary(&Q.Y, &btstack_crypto_ec_p192->public_key[32], 32); 579 mbedtls_mpi_lset(&Q.Z, 1); 580 mbedtls_ecp_mul(&mbedtls_ec_group, &DH, &d, &Q, NULL, NULL); 581 mbedtls_mpi_write_binary(&DH.X, btstack_crypto_ec_p192->dhkey, 32); 582 mbedtls_ecp_point_free(&DH); 583 mbedtls_mpi_free(&d); 584 mbedtls_ecp_point_free(&Q); 585 #endif 586 587 log_info("dhkey"); 588 log_info_hexdump(btstack_crypto_ec_p192->dhkey, 32); 589 } 590 #endif 591 592 #endif 593 594 static void btstack_crypto_ccm_next_block(btstack_crypto_ccm_t * btstack_crypto_ccm, btstack_crypto_ccm_state_t state_when_done){ 595 uint16_t bytes_to_process = btstack_min(btstack_crypto_ccm->block_len, 16); 596 // next block 597 btstack_crypto_ccm->counter++; 598 btstack_crypto_ccm->input += bytes_to_process; 599 btstack_crypto_ccm->output += bytes_to_process; 600 btstack_crypto_ccm->block_len -= bytes_to_process; 601 btstack_crypto_ccm->message_len -= bytes_to_process; 602 #ifdef DEBUG_CCM 603 printf("btstack_crypto_ccm_next_block (message len %u, block_len %u)\n", btstack_crypto_ccm->message_len, btstack_crypto_ccm->block_len); 604 #endif 605 if (btstack_crypto_ccm->message_len == 0u){ 606 btstack_crypto_ccm->state = CCM_CALCULATE_S0; 607 } else { 608 btstack_crypto_ccm->state = state_when_done; 609 if (btstack_crypto_ccm->block_len == 0u){ 610 btstack_crypto_done(&btstack_crypto_ccm->btstack_crypto); 611 } 612 } 613 } 614 615 // If Controller is used for AES128, data is little endian 616 static void btstack_crypto_ccm_handle_s0(btstack_crypto_ccm_t * btstack_crypto_ccm, const uint8_t * data){ 617 int i; 618 for (i=0;i<16;i++){ 619 #ifdef USE_BTSTACK_AES128 620 btstack_crypto_ccm->x_i[i] = btstack_crypto_ccm->x_i[i] ^ data[i]; 621 #else 622 btstack_crypto_ccm->x_i[i] = btstack_crypto_ccm->x_i[i] ^ data[15-i]; 623 #endif 624 } 625 btstack_crypto_done(&btstack_crypto_ccm->btstack_crypto); 626 } 627 628 // If Controller is used for AES128, data is little endian 629 static void btstack_crypto_ccm_handle_sn(btstack_crypto_ccm_t * btstack_crypto_ccm, const uint8_t * data){ 630 int i; 631 uint16_t bytes_to_process = btstack_min(btstack_crypto_ccm->block_len, 16); 632 for (i=0;i<bytes_to_process;i++){ 633 #ifdef USE_BTSTACK_AES128 634 btstack_crypto_ccm->output[i] = btstack_crypto_ccm->input[i] ^ data[i]; 635 #else 636 btstack_crypto_ccm->output[i] = btstack_crypto_ccm->input[i] ^ data[15-i]; 637 #endif 638 } 639 switch (btstack_crypto_ccm->btstack_crypto.operation){ 640 case BTSTACK_CRYPTO_CCM_DECRYPT_BLOCK: 641 btstack_crypto_ccm->state = CCM_CALCULATE_XN; 642 break; 643 case BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK: 644 btstack_crypto_ccm_next_block(btstack_crypto_ccm, CCM_CALCULATE_XN); 645 break; 646 default: 647 btstack_assert(false); 648 break; 649 } 650 } 651 652 static void btstack_crypto_ccm_handle_aad_xn(btstack_crypto_ccm_t * btstack_crypto_ccm) { 653 #ifdef DEBUG_CCM 654 printf("%16s: ", "Xn+1 AAD"); 655 printf_hexdump(btstack_crypto_ccm->x_i, 16); 656 #endif 657 // more aad? 658 if (btstack_crypto_ccm->aad_offset < (btstack_crypto_ccm->aad_len + 2u)){ 659 btstack_crypto_ccm->state = CCM_CALCULATE_AAD_XN; 660 } else { 661 // done 662 btstack_crypto_done((btstack_crypto_t *) btstack_crypto_ccm); 663 } 664 } 665 666 static void btstack_crypto_ccm_handle_x1(btstack_crypto_ccm_t * btstack_crypto_ccm) { 667 #ifdef DEBUG_CCM 668 printf("%16s: ", "Xi"); 669 printf_hexdump(btstack_crypto_ccm->x_i, 16); 670 #endif 671 switch (btstack_crypto_ccm->btstack_crypto.operation){ 672 case BTSTACK_CRYPTO_CCM_DIGEST_BLOCK: 673 btstack_crypto_ccm->aad_remainder_len = 0; 674 btstack_crypto_ccm->state = CCM_CALCULATE_AAD_XN; 675 break; 676 case BTSTACK_CRYPTO_CCM_DECRYPT_BLOCK: 677 btstack_crypto_ccm->state = CCM_CALCULATE_SN; 678 break; 679 case BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK: 680 btstack_crypto_ccm->state = CCM_CALCULATE_XN; 681 break; 682 default: 683 btstack_assert(false); 684 break; 685 } 686 } 687 688 static void btstack_crypto_ccm_handle_xn(btstack_crypto_ccm_t * btstack_crypto_ccm) { 689 #ifdef DEBUG_CCM 690 printf("%16s: ", "Xn+1"); 691 printf_hexdump(btstack_crypto_ccm->x_i, 16); 692 #endif 693 switch (btstack_crypto_ccm->btstack_crypto.operation){ 694 case BTSTACK_CRYPTO_CCM_DECRYPT_BLOCK: 695 btstack_crypto_ccm_next_block(btstack_crypto_ccm, CCM_CALCULATE_SN); 696 break; 697 case BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK: 698 btstack_crypto_ccm->state = CCM_CALCULATE_SN; 699 break; 700 default: 701 btstack_assert(false); 702 break; 703 } 704 } 705 706 static void btstack_crypto_ccm_calc_s0(btstack_crypto_ccm_t * btstack_crypto_ccm){ 707 #ifdef DEBUG_CCM 708 printf("btstack_crypto_ccm_calc_s0\n"); 709 #endif 710 btstack_crypto_ccm->state = CCM_W4_S0; 711 btstack_crypto_ccm_setup_a_i(btstack_crypto_ccm, 0); 712 #ifdef USE_BTSTACK_AES128 713 uint8_t data[16]; 714 btstack_aes128_calc(btstack_crypto_ccm->key, btstack_crypto_ccm_s, data); 715 btstack_crypto_ccm_handle_s0(btstack_crypto_ccm, data); 716 #else 717 btstack_crypto_aes128_start(btstack_crypto_ccm->key, btstack_crypto_ccm_s); 718 #endif 719 } 720 721 static void btstack_crypto_ccm_calc_sn(btstack_crypto_ccm_t * btstack_crypto_ccm){ 722 #ifdef DEBUG_CCM 723 printf("btstack_crypto_ccm_calc_s%u\n", btstack_crypto_ccm->counter); 724 #endif 725 btstack_crypto_ccm->state = CCM_W4_SN; 726 btstack_crypto_ccm_setup_a_i(btstack_crypto_ccm, btstack_crypto_ccm->counter); 727 #ifdef USE_BTSTACK_AES128 728 uint8_t data[16]; 729 btstack_aes128_calc(btstack_crypto_ccm->key, btstack_crypto_ccm_s, data); 730 btstack_crypto_ccm_handle_sn(btstack_crypto_ccm, data); 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_calc_xn(btstack_crypto_ccm_t * btstack_crypto_ccm, const uint8_t * plaintext){ 749 uint8_t btstack_crypto_ccm_buffer[16]; 750 btstack_crypto_ccm->state = CCM_W4_XN; 751 752 #ifdef DEBUG_CCM 753 printf("%16s: ", "bn"); 754 printf_hexdump(plaintext, 16); 755 #endif 756 uint8_t i; 757 uint8_t bytes_to_decrypt = btstack_crypto_ccm->block_len; 758 // use explicit min implementation as c-stat worried about out-of-bounds-reads 759 if (bytes_to_decrypt > 16u) { 760 bytes_to_decrypt = 16; 761 } 762 for (i = 0; i < bytes_to_decrypt ; i++){ 763 btstack_crypto_ccm_buffer[i] = btstack_crypto_ccm->x_i[i] ^ plaintext[i]; 764 } 765 (void)memcpy(&btstack_crypto_ccm_buffer[i], &btstack_crypto_ccm->x_i[i], 766 16u - bytes_to_decrypt); 767 #ifdef DEBUG_CCM 768 printf("%16s: ", "Xn XOR bn"); 769 printf_hexdump(btstack_crypto_ccm_buffer, 16); 770 #endif 771 772 #ifdef USE_BTSTACK_AES128 773 btstack_aes128_calc(btstack_crypto_ccm->key, btstack_crypto_ccm_buffer, btstack_crypto_ccm->x_i); 774 btstack_crypto_ccm_handle_xn(btstack_crypto_ccm); 775 #else 776 btstack_crypto_aes128_start(btstack_crypto_ccm->key, btstack_crypto_ccm_buffer); 777 #endif 778 } 779 780 static void btstack_crypto_ccm_calc_aad_xn(btstack_crypto_ccm_t * btstack_crypto_ccm){ 781 // store length 782 if (btstack_crypto_ccm->aad_offset == 0u){ 783 uint8_t len_buffer[2]; 784 big_endian_store_16(len_buffer, 0, btstack_crypto_ccm->aad_len); 785 btstack_crypto_ccm->x_i[0] ^= len_buffer[0]; 786 btstack_crypto_ccm->x_i[1] ^= len_buffer[1]; 787 btstack_crypto_ccm->aad_remainder_len += 2u; 788 btstack_crypto_ccm->aad_offset += 2u; 789 } 790 791 // fill from input 792 uint16_t bytes_free = 16u - btstack_crypto_ccm->aad_remainder_len; 793 uint16_t bytes_to_copy = btstack_min(bytes_free, btstack_crypto_ccm->block_len); 794 while (bytes_to_copy){ 795 btstack_crypto_ccm->x_i[btstack_crypto_ccm->aad_remainder_len++] ^= *btstack_crypto_ccm->input++; 796 btstack_crypto_ccm->aad_offset++; 797 btstack_crypto_ccm->block_len--; 798 bytes_to_copy--; 799 bytes_free--; 800 } 801 802 // if last block, fill with zeros 803 if (btstack_crypto_ccm->aad_offset == (btstack_crypto_ccm->aad_len + 2u)){ 804 btstack_crypto_ccm->aad_remainder_len = 16; 805 } 806 // if not full, notify done 807 if (btstack_crypto_ccm->aad_remainder_len < 16u){ 808 btstack_crypto_done(&btstack_crypto_ccm->btstack_crypto); 809 return; 810 } 811 812 // encrypt block 813 #ifdef DEBUG_CCM 814 printf("%16s: ", "Xn XOR Bn (aad)"); 815 printf_hexdump(btstack_crypto_ccm->x_i, 16); 816 #endif 817 818 btstack_crypto_ccm->aad_remainder_len = 0; 819 btstack_crypto_ccm->state = CCM_W4_AAD_XN; 820 #ifdef USE_BTSTACK_AES128 821 btstack_aes128_calc(btstack_crypto_ccm->key, btstack_crypto_ccm->x_i, btstack_crypto_ccm->x_i); 822 btstack_crypto_ccm_handle_aad_xn(btstack_crypto_ccm); 823 #else 824 btstack_crypto_aes128_start(btstack_crypto_ccm->key, btstack_crypto_ccm->x_i); 825 #endif 826 } 827 828 static void btstack_crypto_run(void){ 829 830 btstack_crypto_aes128_t * btstack_crypto_aes128; 831 btstack_crypto_ccm_t * btstack_crypto_ccm; 832 btstack_crypto_aes128_cmac_t * btstack_crypto_cmac; 833 #ifdef ENABLE_ECC_P256 834 btstack_crypto_ecc_p256_t * btstack_crypto_ec_p192; 835 #endif 836 837 // stack up and running? 838 if (hci_get_state() != HCI_STATE_WORKING) return; 839 840 // try to do as much as possible 841 while (true){ 842 843 // anything to do? 844 if (btstack_linked_list_empty(&btstack_crypto_operations)) return; 845 846 // already active? 847 if (btstack_crypto_wait_for_hci_result) return; 848 849 // can send a command? 850 if (!hci_can_send_command_packet_now()) return; 851 852 // ok, find next task 853 btstack_crypto_t * btstack_crypto = (btstack_crypto_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 854 switch (btstack_crypto->operation){ 855 case BTSTACK_CRYPTO_RANDOM: 856 btstack_crypto_wait_for_hci_result = true; 857 hci_send_cmd(&hci_le_rand); 858 break; 859 case BTSTACK_CRYPTO_AES128: 860 btstack_crypto_aes128 = (btstack_crypto_aes128_t *) btstack_crypto; 861 #ifdef USE_BTSTACK_AES128 862 btstack_aes128_calc(btstack_crypto_aes128->key, btstack_crypto_aes128->plaintext, btstack_crypto_aes128->ciphertext); 863 btstack_crypto_done(btstack_crypto); 864 #else 865 btstack_crypto_aes128_start(btstack_crypto_aes128->key, btstack_crypto_aes128->plaintext); 866 #endif 867 break; 868 869 case BTSTACK_CRYPTO_CMAC_MESSAGE: 870 case BTSTACK_CRYPTO_CMAC_GENERATOR: 871 btstack_crypto_cmac = (btstack_crypto_aes128_cmac_t *) btstack_crypto; 872 #ifdef USE_BTSTACK_AES128 873 btstack_crypto_cmac_calc( btstack_crypto_cmac ); 874 btstack_crypto_done(btstack_crypto); 875 #else 876 btstack_crypto_wait_for_hci_result = 1; 877 if (btstack_crypto_cmac_state == CMAC_IDLE){ 878 btstack_crypto_cmac_start(btstack_crypto_cmac); 879 } else { 880 btstack_crypto_cmac_handle_aes_engine_ready(btstack_crypto_cmac); 881 } 882 #endif 883 break; 884 885 case BTSTACK_CRYPTO_CCM_DIGEST_BLOCK: 886 case BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK: 887 case BTSTACK_CRYPTO_CCM_DECRYPT_BLOCK: 888 btstack_crypto_ccm = (btstack_crypto_ccm_t *) btstack_crypto; 889 switch (btstack_crypto_ccm->state){ 890 case CCM_CALCULATE_AAD_XN: 891 #ifdef DEBUG_CCM 892 printf("CCM_CALCULATE_AAD_XN\n"); 893 #endif 894 btstack_crypto_ccm_calc_aad_xn(btstack_crypto_ccm); 895 break; 896 case CCM_CALCULATE_X1: 897 #ifdef DEBUG_CCM 898 printf("CCM_CALCULATE_X1\n"); 899 #endif 900 btstack_crypto_ccm_calc_x1(btstack_crypto_ccm); 901 break; 902 case CCM_CALCULATE_S0: 903 #ifdef DEBUG_CCM 904 printf("CCM_CALCULATE_S0\n"); 905 #endif 906 btstack_crypto_ccm_calc_s0(btstack_crypto_ccm); 907 break; 908 case CCM_CALCULATE_SN: 909 #ifdef DEBUG_CCM 910 printf("CCM_CALCULATE_SN\n"); 911 #endif 912 btstack_crypto_ccm_calc_sn(btstack_crypto_ccm); 913 break; 914 case CCM_CALCULATE_XN: 915 #ifdef DEBUG_CCM 916 printf("CCM_CALCULATE_XN\n"); 917 #endif 918 btstack_crypto_ccm_calc_xn(btstack_crypto_ccm, (btstack_crypto->operation == BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK) ? btstack_crypto_ccm->input : btstack_crypto_ccm->output); 919 break; 920 default: 921 break; 922 } 923 break; 924 925 #ifdef ENABLE_ECC_P256 926 case BTSTACK_CRYPTO_ECC_P256_GENERATE_KEY: 927 btstack_crypto_ec_p192 = (btstack_crypto_ecc_p256_t *) btstack_crypto; 928 switch (btstack_crypto_ecc_p256_key_generation_state){ 929 case ECC_P256_KEY_GENERATION_DONE: 930 // done 931 btstack_crypto_log_ec_publickey(btstack_crypto_ecc_p256_public_key); 932 (void)memcpy(btstack_crypto_ec_p192->public_key, 933 btstack_crypto_ecc_p256_public_key, 64); 934 btstack_linked_list_pop(&btstack_crypto_operations); 935 (*btstack_crypto_ec_p192->btstack_crypto.context_callback.callback)(btstack_crypto_ec_p192->btstack_crypto.context_callback.context); 936 break; 937 case ECC_P256_KEY_GENERATION_IDLE: 938 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 939 log_info("start ecc random"); 940 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_GENERATING_RANDOM; 941 btstack_crypto_ecc_p256_random_offset = 0; 942 btstack_crypto_wait_for_hci_result = true; 943 hci_send_cmd(&hci_le_rand); 944 #else 945 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_W4_KEY; 946 btstack_crypto_wait_for_hci_result = 1; 947 hci_send_cmd(&hci_le_read_local_p256_public_key); 948 #endif 949 break; 950 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 951 case ECC_P256_KEY_GENERATION_GENERATING_RANDOM: 952 log_info("more ecc random"); 953 btstack_crypto_wait_for_hci_result = true; 954 hci_send_cmd(&hci_le_rand); 955 break; 956 #endif 957 default: 958 break; 959 } 960 break; 961 case BTSTACK_CRYPTO_ECC_P256_CALCULATE_DHKEY: 962 btstack_crypto_ec_p192 = (btstack_crypto_ecc_p256_t *) btstack_crypto; 963 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 964 btstack_crypto_ecc_p256_calculate_dhkey_software(btstack_crypto_ec_p192); 965 // done 966 btstack_linked_list_pop(&btstack_crypto_operations); 967 (*btstack_crypto_ec_p192->btstack_crypto.context_callback.callback)(btstack_crypto_ec_p192->btstack_crypto.context_callback.context); 968 #else 969 btstack_crypto_wait_for_hci_result = 1; 970 hci_send_cmd(&hci_le_generate_dhkey, &btstack_crypto_ec_p192->public_key[0], &btstack_crypto_ec_p192->public_key[32]); 971 #endif 972 break; 973 974 #endif /* ENABLE_ECC_P256 */ 975 976 default: 977 break; 978 } 979 } 980 } 981 982 static void btstack_crypto_handle_random_data(const uint8_t * data, uint16_t len){ 983 btstack_crypto_random_t * btstack_crypto_random; 984 btstack_crypto_t * btstack_crypto = (btstack_crypto_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 985 uint16_t bytes_to_copy; 986 if (!btstack_crypto) return; 987 switch (btstack_crypto->operation){ 988 case BTSTACK_CRYPTO_RANDOM: 989 btstack_crypto_random = (btstack_crypto_random_t*) btstack_crypto; 990 bytes_to_copy = btstack_min(btstack_crypto_random->size, len); 991 (void)memcpy(btstack_crypto_random->buffer, data, bytes_to_copy); 992 btstack_crypto_random->buffer += bytes_to_copy; 993 btstack_crypto_random->size -= bytes_to_copy; 994 // data processed, more? 995 if (!btstack_crypto_random->size) { 996 // done 997 btstack_linked_list_pop(&btstack_crypto_operations); 998 (*btstack_crypto_random->btstack_crypto.context_callback.callback)(btstack_crypto_random->btstack_crypto.context_callback.context); 999 } 1000 break; 1001 #ifdef ENABLE_ECC_P256 1002 case BTSTACK_CRYPTO_ECC_P256_GENERATE_KEY: 1003 (void)memcpy(&btstack_crypto_ecc_p256_random[btstack_crypto_ecc_p256_random_len], 1004 data, 8); 1005 btstack_crypto_ecc_p256_random_len += 8u; 1006 if (btstack_crypto_ecc_p256_random_len >= 64u) { 1007 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_ACTIVE; 1008 btstack_crypto_ecc_p256_generate_key_software(); 1009 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_DONE; 1010 } 1011 break; 1012 #endif 1013 default: 1014 break; 1015 } 1016 // more work? 1017 btstack_crypto_run(); 1018 } 1019 1020 #ifndef USE_BTSTACK_AES128 1021 static void btstack_crypto_handle_encryption_result(const uint8_t * data){ 1022 btstack_crypto_aes128_t * btstack_crypto_aes128; 1023 btstack_crypto_aes128_cmac_t * btstack_crypto_cmac; 1024 btstack_crypto_ccm_t * btstack_crypto_ccm; 1025 uint8_t result[16]; 1026 1027 btstack_crypto_t * btstack_crypto = (btstack_crypto_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 1028 if (!btstack_crypto) return; 1029 switch (btstack_crypto->operation){ 1030 case BTSTACK_CRYPTO_AES128: 1031 btstack_crypto_aes128 = (btstack_crypto_aes128_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 1032 reverse_128(data, btstack_crypto_aes128->ciphertext); 1033 btstack_crypto_done(btstack_crypto); 1034 break; 1035 case BTSTACK_CRYPTO_CMAC_GENERATOR: 1036 case BTSTACK_CRYPTO_CMAC_MESSAGE: 1037 btstack_crypto_cmac = (btstack_crypto_aes128_cmac_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 1038 reverse_128(data, result); 1039 btstack_crypto_cmac_handle_encryption_result(btstack_crypto_cmac, result); 1040 break; 1041 case BTSTACK_CRYPTO_CCM_DIGEST_BLOCK: 1042 case BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK: 1043 case BTSTACK_CRYPTO_CCM_DECRYPT_BLOCK: 1044 btstack_crypto_ccm = (btstack_crypto_ccm_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 1045 switch (btstack_crypto_ccm->state){ 1046 case CCM_W4_X1: 1047 reverse_128(data, btstack_crypto_ccm->x_i); 1048 btstack_crypto_ccm_handle_x1(btstack_crypto_ccm); 1049 break; 1050 case CCM_W4_XN: 1051 reverse_128(data, btstack_crypto_ccm->x_i); 1052 btstack_crypto_ccm_handle_xn(btstack_crypto_ccm); 1053 break; 1054 case CCM_W4_AAD_XN: 1055 reverse_128(data, btstack_crypto_ccm->x_i); 1056 btstack_crypto_ccm_handle_aad_xn(btstack_crypto_ccm); 1057 break; 1058 case CCM_W4_S0: 1059 btstack_crypto_ccm_handle_s0(btstack_crypto_ccm, data); 1060 break; 1061 case CCM_W4_SN: 1062 btstack_crypto_ccm_handle_sn(btstack_crypto_ccm, data); 1063 break; 1064 default: 1065 break; 1066 } 1067 break; 1068 default: 1069 break; 1070 } 1071 } 1072 #endif 1073 1074 static void btstack_crypto_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1075 UNUSED(cid); // ok: there is no channel 1076 UNUSED(size); // ok: fixed format events read from HCI buffer 1077 1078 #ifdef ENABLE_ECC_P256 1079 #ifndef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 1080 btstack_crypto_ecc_p256_t * btstack_crypto_ec_p192; 1081 #endif 1082 #endif 1083 1084 if (packet_type != HCI_EVENT_PACKET) return; 1085 1086 switch (hci_event_packet_get_type(packet)){ 1087 case BTSTACK_EVENT_STATE: 1088 if (btstack_event_state_get_state(packet) != HCI_STATE_HALTING) break; 1089 if (!btstack_crypto_wait_for_hci_result) break; 1090 // request stack to defer shutdown a bit 1091 hci_halting_defer(); 1092 break; 1093 1094 case HCI_EVENT_COMMAND_COMPLETE: 1095 #ifndef USE_BTSTACK_AES128 1096 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 1097 if (!btstack_crypto_wait_for_hci_result) return; 1098 btstack_crypto_wait_for_hci_result = 0; 1099 btstack_crypto_handle_encryption_result(&packet[6]); 1100 } 1101 #endif 1102 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 1103 if (!btstack_crypto_wait_for_hci_result) return; 1104 btstack_crypto_wait_for_hci_result = false; 1105 btstack_crypto_handle_random_data(&packet[6], 8); 1106 } 1107 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_local_supported_commands)){ 1108 int ecdh_operations_supported = (packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+34u] & 0x06u) == 0x06u; 1109 UNUSED(ecdh_operations_supported); 1110 log_info("controller supports ECDH operation: %u", ecdh_operations_supported); 1111 #ifdef ENABLE_ECC_P256 1112 #ifndef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 1113 // Assert controller supports ECDH operation if we don't implement them ourselves 1114 // Please add ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS to btstack_config.h and add 3rd-party/micro-ecc to your port 1115 btstack_assert(ecdh_operations_supported != 0); 1116 #endif 1117 #endif 1118 } 1119 break; 1120 1121 #ifdef ENABLE_ECC_P256 1122 #ifndef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 1123 case HCI_EVENT_LE_META: 1124 btstack_crypto_ec_p192 = (btstack_crypto_ecc_p256_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 1125 if (!btstack_crypto_ec_p192) break; 1126 switch (hci_event_le_meta_get_subevent_code(packet)){ 1127 case HCI_SUBEVENT_LE_READ_LOCAL_P256_PUBLIC_KEY_COMPLETE: 1128 if (btstack_crypto_ec_p192->btstack_crypto.operation != BTSTACK_CRYPTO_ECC_P256_GENERATE_KEY) break; 1129 if (!btstack_crypto_wait_for_hci_result) return; 1130 btstack_crypto_wait_for_hci_result = 0; 1131 if (hci_subevent_le_read_local_p256_public_key_complete_get_status(packet)){ 1132 log_error("Read Local P256 Public Key failed"); 1133 } 1134 hci_subevent_le_read_local_p256_public_key_complete_get_dhkey_x(packet, &btstack_crypto_ecc_p256_public_key[0]); 1135 hci_subevent_le_read_local_p256_public_key_complete_get_dhkey_y(packet, &btstack_crypto_ecc_p256_public_key[32]); 1136 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_DONE; 1137 break; 1138 case HCI_SUBEVENT_LE_GENERATE_DHKEY_COMPLETE: 1139 if (btstack_crypto_ec_p192->btstack_crypto.operation != BTSTACK_CRYPTO_ECC_P256_CALCULATE_DHKEY) break; 1140 if (!btstack_crypto_wait_for_hci_result) return; 1141 btstack_crypto_wait_for_hci_result = 0; 1142 if (hci_subevent_le_generate_dhkey_complete_get_status(packet)){ 1143 log_error("Generate DHKEY failed -> abort"); 1144 } 1145 hci_subevent_le_generate_dhkey_complete_get_dhkey(packet, btstack_crypto_ec_p192->dhkey); 1146 // done 1147 btstack_linked_list_pop(&btstack_crypto_operations); 1148 (*btstack_crypto_ec_p192->btstack_crypto.context_callback.callback)(btstack_crypto_ec_p192->btstack_crypto.context_callback.context); 1149 break; 1150 default: 1151 break; 1152 } 1153 break; 1154 #endif 1155 #endif 1156 default: 1157 break; 1158 } 1159 1160 // try processing 1161 btstack_crypto_run(); 1162 } 1163 1164 void btstack_crypto_init(void){ 1165 if (btstack_crypto_initialized) return; 1166 btstack_crypto_initialized = true; 1167 1168 // register with HCI 1169 hci_event_callback_registration.callback = &btstack_crypto_event_handler; 1170 hci_add_event_handler(&hci_event_callback_registration); 1171 1172 #ifdef USE_MBEDTLS_ECC_P256 1173 mbedtls_ecp_group_init(&mbedtls_ec_group); 1174 mbedtls_ecp_group_load(&mbedtls_ec_group, MBEDTLS_ECP_DP_SECP256R1); 1175 #endif 1176 } 1177 1178 void btstack_crypto_random_generate(btstack_crypto_random_t * request, uint8_t * buffer, uint16_t size, void (* callback)(void * arg), void * callback_arg){ 1179 request->btstack_crypto.context_callback.callback = callback; 1180 request->btstack_crypto.context_callback.context = callback_arg; 1181 request->btstack_crypto.operation = BTSTACK_CRYPTO_RANDOM; 1182 request->buffer = buffer; 1183 request->size = size; 1184 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1185 btstack_crypto_run(); 1186 } 1187 1188 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){ 1189 request->btstack_crypto.context_callback.callback = callback; 1190 request->btstack_crypto.context_callback.context = callback_arg; 1191 request->btstack_crypto.operation = BTSTACK_CRYPTO_AES128; 1192 request->key = key; 1193 request->plaintext = plaintext; 1194 request->ciphertext = ciphertext; 1195 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1196 btstack_crypto_run(); 1197 } 1198 1199 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){ 1200 request->btstack_crypto.context_callback.callback = callback; 1201 request->btstack_crypto.context_callback.context = callback_arg; 1202 request->btstack_crypto.operation = BTSTACK_CRYPTO_CMAC_GENERATOR; 1203 request->key = key; 1204 request->size = size; 1205 request->data.get_byte_callback = get_byte_callback; 1206 request->hash = hash; 1207 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1208 btstack_crypto_run(); 1209 } 1210 1211 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){ 1212 request->btstack_crypto.context_callback.callback = callback; 1213 request->btstack_crypto.context_callback.context = callback_arg; 1214 request->btstack_crypto.operation = BTSTACK_CRYPTO_CMAC_MESSAGE; 1215 request->key = key; 1216 request->size = size; 1217 request->data.message = message; 1218 request->hash = hash; 1219 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1220 btstack_crypto_run(); 1221 } 1222 1223 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){ 1224 request->btstack_crypto.context_callback.callback = callback; 1225 request->btstack_crypto.context_callback.context = callback_arg; 1226 request->btstack_crypto.operation = BTSTACK_CRYPTO_CMAC_MESSAGE; 1227 request->key = zero; 1228 request->size = len; 1229 request->data.message = message; 1230 request->hash = hash; 1231 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1232 btstack_crypto_run(); 1233 } 1234 1235 #ifdef ENABLE_ECC_P256 1236 void btstack_crypto_ecc_p256_generate_key(btstack_crypto_ecc_p256_t * request, uint8_t * public_key, void (* callback)(void * arg), void * callback_arg){ 1237 // reset key generation 1238 if (btstack_crypto_ecc_p256_key_generation_state == ECC_P256_KEY_GENERATION_DONE){ 1239 btstack_crypto_ecc_p256_random_len = 0; 1240 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_IDLE; 1241 } 1242 request->btstack_crypto.context_callback.callback = callback; 1243 request->btstack_crypto.context_callback.context = callback_arg; 1244 request->btstack_crypto.operation = BTSTACK_CRYPTO_ECC_P256_GENERATE_KEY; 1245 request->public_key = public_key; 1246 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1247 btstack_crypto_run(); 1248 } 1249 1250 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){ 1251 request->btstack_crypto.context_callback.callback = callback; 1252 request->btstack_crypto.context_callback.context = callback_arg; 1253 request->btstack_crypto.operation = BTSTACK_CRYPTO_ECC_P256_CALCULATE_DHKEY; 1254 request->public_key = (uint8_t *) public_key; 1255 request->dhkey = dhkey; 1256 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1257 btstack_crypto_run(); 1258 } 1259 1260 int btstack_crypto_ecc_p256_validate_public_key(const uint8_t * public_key){ 1261 1262 // validate public key using micro-ecc 1263 int err = 0; 1264 1265 #ifdef USE_MICRO_ECC_P256 1266 #if uECC_SUPPORTS_secp256r1 1267 // standard version 1268 err = uECC_valid_public_key(public_key, uECC_secp256r1()) == 0; 1269 #else 1270 // static version 1271 err = uECC_valid_public_key(public_key) == 0; 1272 #endif 1273 #endif 1274 1275 #ifdef USE_MBEDTLS_ECC_P256 1276 mbedtls_ecp_point Q; 1277 mbedtls_ecp_point_init( &Q ); 1278 mbedtls_mpi_read_binary(&Q.X, &public_key[0], 32); 1279 mbedtls_mpi_read_binary(&Q.Y, &public_key[32], 32); 1280 mbedtls_mpi_lset(&Q.Z, 1); 1281 err = mbedtls_ecp_check_pubkey(&mbedtls_ec_group, &Q); 1282 mbedtls_ecp_point_free( & Q); 1283 #endif 1284 1285 if (err != 0){ 1286 log_error("public key invalid %x", err); 1287 } 1288 return err; 1289 } 1290 #endif 1291 1292 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){ 1293 request->key = key; 1294 request->nonce = nonce; 1295 request->message_len = message_len; 1296 request->aad_len = additional_authenticated_data_len; 1297 request->aad_offset = 0; 1298 request->auth_len = auth_len; 1299 request->counter = 1; 1300 request->state = CCM_CALCULATE_X1; 1301 } 1302 1303 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){ 1304 // not implemented yet 1305 request->btstack_crypto.context_callback.callback = callback; 1306 request->btstack_crypto.context_callback.context = callback_arg; 1307 request->btstack_crypto.operation = BTSTACK_CRYPTO_CCM_DIGEST_BLOCK; 1308 request->block_len = additional_authenticated_data_len; 1309 request->input = additional_authenticated_data; 1310 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1311 btstack_crypto_run(); 1312 } 1313 1314 void btstack_crypto_ccm_get_authentication_value(btstack_crypto_ccm_t * request, uint8_t * authentication_value){ 1315 (void)memcpy(authentication_value, request->x_i, request->auth_len); 1316 } 1317 1318 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){ 1319 #ifdef DEBUG_CCM 1320 printf("\nbtstack_crypto_ccm_encrypt_block, len %u\n", block_len); 1321 #endif 1322 request->btstack_crypto.context_callback.callback = callback; 1323 request->btstack_crypto.context_callback.context = callback_arg; 1324 request->btstack_crypto.operation = BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK; 1325 request->block_len = block_len; 1326 request->input = plaintext; 1327 request->output = ciphertext; 1328 if (request->state != CCM_CALCULATE_X1){ 1329 request->state = CCM_CALCULATE_XN; 1330 } 1331 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1332 btstack_crypto_run(); 1333 } 1334 1335 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){ 1336 request->btstack_crypto.context_callback.callback = callback; 1337 request->btstack_crypto.context_callback.context = callback_arg; 1338 request->btstack_crypto.operation = BTSTACK_CRYPTO_CCM_DECRYPT_BLOCK; 1339 request->block_len = block_len; 1340 request->input = ciphertext; 1341 request->output = plaintext; 1342 if (request->state != CCM_CALCULATE_X1){ 1343 request->state = CCM_CALCULATE_SN; 1344 } 1345 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1346 btstack_crypto_run(); 1347 } 1348 1349 // De-Init 1350 void btstack_crypto_deinit(void) { 1351 btstack_crypto_initialized = false; 1352 btstack_crypto_wait_for_hci_result = false; 1353 btstack_crypto_operations = NULL; 1354 } 1355 1356 // PTS only 1357 void btstack_crypto_ecc_p256_set_key(const uint8_t * public_key, const uint8_t * private_key){ 1358 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 1359 (void)memcpy(btstack_crypto_ecc_p256_d, private_key, 32); 1360 (void)memcpy(btstack_crypto_ecc_p256_public_key, public_key, 64); 1361 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_DONE; 1362 #else 1363 UNUSED(public_key); 1364 UNUSED(private_key); 1365 #endif 1366 } 1367 1368 // Unit testing 1369 int btstack_crypto_idle(void){ 1370 return btstack_linked_list_empty(&btstack_crypto_operations); 1371 } 1372 void btstack_crypto_reset(void){ 1373 btstack_crypto_deinit(); 1374 btstack_crypto_init(); 1375 } 1376