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 // degbugging 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 #ifndef USE_BTSTACK_AES128 147 static uint8_t btstack_crypto_ccm_s[16]; 148 #endif 149 150 #ifdef ENABLE_ECC_P256 151 152 static uint8_t btstack_crypto_ecc_p256_public_key[64]; 153 static uint8_t btstack_crypto_ecc_p256_random[64]; 154 static uint8_t btstack_crypto_ecc_p256_random_len; 155 static uint8_t btstack_crypto_ecc_p256_random_offset; 156 static btstack_crypto_ecc_p256_key_generation_state_t btstack_crypto_ecc_p256_key_generation_state; 157 158 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 159 static uint8_t btstack_crypto_ecc_p256_d[32]; 160 #endif 161 162 // Software ECDH implementation provided by mbedtls 163 #ifdef USE_MBEDTLS_ECC_P256 164 static mbedtls_ecp_group mbedtls_ec_group; 165 #endif 166 167 #endif /* ENABLE_ECC_P256 */ 168 169 #ifdef ENABLE_SOFTWARE_AES128 170 // AES128 using public domain rijndael implementation 171 void btstack_aes128_calc(const uint8_t * key, const uint8_t * plaintext, uint8_t * ciphertext){ 172 uint32_t rk[RKLENGTH(KEYBITS)]; 173 int nrounds = rijndaelSetupEncrypt(rk, &key[0], KEYBITS); 174 rijndaelEncrypt(rk, nrounds, plaintext, ciphertext); 175 } 176 #endif 177 178 static void btstack_crypto_done(btstack_crypto_t * btstack_crypto){ 179 btstack_linked_list_pop(&btstack_crypto_operations); 180 (*btstack_crypto->context_callback.callback)(btstack_crypto->context_callback.context); 181 } 182 183 static void btstack_crypto_cmac_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 184 int i; 185 int carry = 0; 186 for (i=len-1; i >= 0 ; i--){ 187 int new_carry = data[i] >> 7; 188 data[i] = (data[i] << 1) | carry; 189 carry = new_carry; 190 } 191 } 192 193 static uint8_t btstack_crypto_cmac_get_byte(btstack_crypto_aes128_cmac_t * btstack_crypto_cmac, uint16_t pos){ 194 if (btstack_crypto_cmac->btstack_crypto.operation == BTSTACK_CRYPTO_CMAC_GENERATOR){ 195 return (*btstack_crypto_cmac->data.get_byte_callback)(pos); 196 } else { 197 return btstack_crypto_cmac->data.message[pos]; 198 } 199 } 200 201 #ifdef USE_BTSTACK_AES128 202 203 static void btstack_crypto_cmac_calc_subkeys(sm_key_t k0, sm_key_t k1, sm_key_t k2){ 204 memcpy(k1, k0, 16); 205 btstack_crypto_cmac_shift_left_by_one_bit_inplace(16, k1); 206 if (k0[0] & 0x80){ 207 k1[15] ^= 0x87; 208 } 209 memcpy(k2, k1, 16); 210 btstack_crypto_cmac_shift_left_by_one_bit_inplace(16, k2); 211 if (k1[0] & 0x80){ 212 k2[15] ^= 0x87; 213 } 214 } 215 216 static void btstack_crypto_cmac_calc(btstack_crypto_aes128_cmac_t * btstack_crypto_cmac) { 217 sm_key_t k0, k1, k2; 218 uint16_t i; 219 220 btstack_aes128_calc(btstack_crypto_cmac->key, zero, k0); 221 btstack_crypto_cmac_calc_subkeys(k0, k1, k2); 222 223 uint16_t cmac_block_count = (btstack_crypto_cmac->size + 15) / 16; 224 225 // step 3: .. 226 if (cmac_block_count==0){ 227 cmac_block_count = 1; 228 } 229 230 // Step 5 231 sm_key_t cmac_x; 232 memset(cmac_x, 0, 16); 233 234 // Step 6 235 sm_key_t cmac_y; 236 int block; 237 for (block = 0 ; block < cmac_block_count-1 ; block++){ 238 for (i=0;i<16;i++){ 239 cmac_y[i] = cmac_x[i] ^ btstack_crypto_cmac_get_byte(btstack_crypto_cmac, (block*16) + i); 240 } 241 btstack_aes128_calc(btstack_crypto_cmac->key, cmac_y, cmac_x); 242 } 243 244 // step 4: set m_last 245 sm_key_t cmac_m_last; 246 bool last_block_complete = btstack_crypto_cmac->size != 0 && (btstack_crypto_cmac->size & 0x0f) == 0; 247 if (last_block_complete){ 248 for (i=0;i<16;i++){ 249 cmac_m_last[i] = btstack_crypto_cmac_get_byte(btstack_crypto_cmac, btstack_crypto_cmac->size - 16 + i) ^ k1[i]; 250 } 251 } else { 252 uint16_t valid_octets_in_last_block = btstack_crypto_cmac->size & 0x0f; 253 for (i=0;i<16;i++){ 254 if (i < valid_octets_in_last_block){ 255 cmac_m_last[i] = btstack_crypto_cmac_get_byte(btstack_crypto_cmac, (btstack_crypto_cmac->size & 0xfff0) + i) ^ k2[i]; 256 continue; 257 } 258 if (i == valid_octets_in_last_block){ 259 cmac_m_last[i] = 0x80 ^ k2[i]; 260 continue; 261 } 262 cmac_m_last[i] = k2[i]; 263 } 264 } 265 266 for (i=0;i<16;i++){ 267 cmac_y[i] = cmac_x[i] ^ cmac_m_last[i]; 268 } 269 270 // Step 7 271 btstack_aes128_calc(btstack_crypto_cmac->key, cmac_y, btstack_crypto_cmac->hash); 272 } 273 #else 274 275 static void btstack_crypto_aes128_start(const sm_key_t key, const sm_key_t plaintext){ 276 uint8_t key_flipped[16]; 277 uint8_t plaintext_flipped[16]; 278 reverse_128(key, key_flipped); 279 reverse_128(plaintext, plaintext_flipped); 280 btstack_crypto_wait_for_hci_result = 1; 281 hci_send_cmd(&hci_le_encrypt, key_flipped, plaintext_flipped); 282 } 283 284 static inline void btstack_crypto_cmac_next_state(void){ 285 btstack_crypto_cmac_state = (btstack_crypto_cmac_state_t) (((int)btstack_crypto_cmac_state) + 1); 286 } 287 288 static int btstack_crypto_cmac_last_block_complete(btstack_crypto_aes128_cmac_t * btstack_crypto_cmac){ 289 uint16_t len = btstack_crypto_cmac->size; 290 if (len == 0) return 0; 291 return (len & 0x0f) == 0; 292 } 293 294 static void btstack_crypto_cmac_handle_aes_engine_ready(btstack_crypto_aes128_cmac_t * btstack_crypto_cmac){ 295 switch (btstack_crypto_cmac_state){ 296 case CMAC_CALC_SUBKEYS: { 297 btstack_crypto_cmac_next_state(); 298 btstack_crypto_aes128_start(btstack_crypto_cmac_k, zero); 299 break; 300 } 301 case CMAC_CALC_MI: { 302 int j; 303 sm_key_t y; 304 for (j=0;j<16;j++){ 305 y[j] = btstack_crypto_cmac_x[j] ^ btstack_crypto_cmac_get_byte(btstack_crypto_cmac, (btstack_crypto_cmac_block_current*16) + j); 306 } 307 btstack_crypto_cmac_block_current++; 308 btstack_crypto_cmac_next_state(); 309 btstack_crypto_aes128_start(btstack_crypto_cmac_k, y); 310 break; 311 } 312 case CMAC_CALC_MLAST: { 313 sm_key_t k1; 314 (void)memcpy(k1, btstack_crypto_cmac_subkey, 16); 315 btstack_crypto_cmac_shift_left_by_one_bit_inplace(16, k1); 316 if (btstack_crypto_cmac_subkey[0] & 0x80){ 317 k1[15] ^= 0x87; 318 } 319 sm_key_t k2; 320 (void)memcpy(k2, k1, 16); 321 btstack_crypto_cmac_shift_left_by_one_bit_inplace(16, k2); 322 if (k1[0] & 0x80){ 323 k2[15] ^= 0x87; 324 } 325 326 log_info_key("k", btstack_crypto_cmac_k); 327 log_info_key("k1", k1); 328 log_info_key("k2", k2); 329 330 // step 4: set m_last 331 int i; 332 sm_key_t btstack_crypto_cmac_m_last; 333 if (btstack_crypto_cmac_last_block_complete(btstack_crypto_cmac)){ 334 for (i=0;i<16;i++){ 335 btstack_crypto_cmac_m_last[i] = btstack_crypto_cmac_get_byte(btstack_crypto_cmac, btstack_crypto_cmac->size - 16 + i) ^ k1[i]; 336 } 337 } else { 338 int valid_octets_in_last_block = btstack_crypto_cmac->size & 0x0f; 339 for (i=0;i<16;i++){ 340 if (i < valid_octets_in_last_block){ 341 btstack_crypto_cmac_m_last[i] = btstack_crypto_cmac_get_byte(btstack_crypto_cmac, (btstack_crypto_cmac->size & 0xfff0) + i) ^ k2[i]; 342 continue; 343 } 344 if (i == valid_octets_in_last_block){ 345 btstack_crypto_cmac_m_last[i] = 0x80 ^ k2[i]; 346 continue; 347 } 348 btstack_crypto_cmac_m_last[i] = k2[i]; 349 } 350 } 351 sm_key_t y; 352 for (i=0;i<16;i++){ 353 y[i] = btstack_crypto_cmac_x[i] ^ btstack_crypto_cmac_m_last[i]; 354 } 355 btstack_crypto_cmac_block_current++; 356 btstack_crypto_cmac_next_state(); 357 btstack_crypto_aes128_start(btstack_crypto_cmac_k, y); 358 break; 359 } 360 default: 361 log_info("btstack_crypto_cmac_handle_aes_engine_ready called in state %u", btstack_crypto_cmac_state); 362 break; 363 } 364 } 365 366 static void btstack_crypto_cmac_handle_encryption_result(btstack_crypto_aes128_cmac_t * btstack_crypto_cmac, sm_key_t data){ 367 switch (btstack_crypto_cmac_state){ 368 case CMAC_W4_SUBKEYS: 369 (void)memcpy(btstack_crypto_cmac_subkey, data, 16); 370 // next 371 btstack_crypto_cmac_state = (btstack_crypto_cmac_block_current < (btstack_crypto_cmac_block_count - 1)) ? CMAC_CALC_MI : CMAC_CALC_MLAST; 372 break; 373 case CMAC_W4_MI: 374 (void)memcpy(btstack_crypto_cmac_x, data, 16); 375 btstack_crypto_cmac_state = (btstack_crypto_cmac_block_current < (btstack_crypto_cmac_block_count - 1)) ? CMAC_CALC_MI : CMAC_CALC_MLAST; 376 break; 377 case CMAC_W4_MLAST: 378 // done 379 log_info("Setting CMAC Engine to IDLE"); 380 btstack_crypto_cmac_state = CMAC_IDLE; 381 log_info_key("CMAC", data); 382 (void)memcpy(btstack_crypto_cmac->hash, data, 16); 383 btstack_linked_list_pop(&btstack_crypto_operations); 384 (*btstack_crypto_cmac->btstack_crypto.context_callback.callback)(btstack_crypto_cmac->btstack_crypto.context_callback.context); 385 break; 386 default: 387 log_info("btstack_crypto_cmac_handle_encryption_result called in state %u", btstack_crypto_cmac_state); 388 break; 389 } 390 } 391 392 static void btstack_crypto_cmac_start(btstack_crypto_aes128_cmac_t * btstack_crypto_cmac){ 393 394 (void)memcpy(btstack_crypto_cmac_k, btstack_crypto_cmac->key, 16); 395 memset(btstack_crypto_cmac_x, 0, 16); 396 btstack_crypto_cmac_block_current = 0; 397 398 // step 2: n := ceil(len/const_Bsize); 399 btstack_crypto_cmac_block_count = (btstack_crypto_cmac->size + 15) / 16; 400 401 // step 3: .. 402 if (btstack_crypto_cmac_block_count==0){ 403 btstack_crypto_cmac_block_count = 1; 404 } 405 log_info("btstack_crypto_cmac_start: len %u, block count %u", btstack_crypto_cmac->size, btstack_crypto_cmac_block_count); 406 407 // first, we need to compute l for k1, k2, and m_last 408 btstack_crypto_cmac_state = CMAC_CALC_SUBKEYS; 409 410 // let's go 411 btstack_crypto_cmac_handle_aes_engine_ready(btstack_crypto_cmac); 412 } 413 #endif 414 415 #ifndef USE_BTSTACK_AES128 416 417 /* 418 To encrypt the message data we use Counter (CTR) mode. We first 419 define the key stream blocks by: 420 421 S_i := E( K, A_i ) for i=0, 1, 2, ... 422 423 The values A_i are formatted as follows, where the Counter field i is 424 encoded in most-significant-byte first order: 425 426 Octet Number Contents 427 ------------ --------- 428 0 Flags 429 1 ... 15-L Nonce N 430 16-L ... 15 Counter i 431 432 Bit Number Contents 433 ---------- ---------------------- 434 7 Reserved (always zero) 435 6 Reserved (always zero) 436 5 ... 3 Zero 437 2 ... 0 L' 438 */ 439 440 static void btstack_crypto_ccm_setup_a_i(btstack_crypto_ccm_t * btstack_crypto_ccm, uint16_t counter){ 441 btstack_crypto_ccm_s[0] = 1; // L' = L - 1 442 (void)memcpy(&btstack_crypto_ccm_s[1], btstack_crypto_ccm->nonce, 13); 443 big_endian_store_16(btstack_crypto_ccm_s, 14, counter); 444 #ifdef DEBUG_CCM 445 printf("ststack_crypto_ccm_setup_a_%u\n", counter); 446 printf("%16s: ", "ai"); 447 printf_hexdump(btstack_crypto_ccm_s, 16); 448 #endif 449 } 450 451 /* 452 The first step is to compute the authentication field T. This is 453 done using CBC-MAC [MAC]. We first define a sequence of blocks B_0, 454 B_1, ..., B_n and then apply CBC-MAC to these blocks. 455 456 The first block B_0 is formatted as follows, where l(m) is encoded in 457 most-significant-byte first order: 458 459 Octet Number Contents 460 ------------ --------- 461 0 Flags 462 1 ... 15-L Nonce N 463 16-L ... 15 l(m) 464 465 Within the first block B_0, the Flags field is formatted as follows: 466 467 Bit Number Contents 468 ---------- ---------------------- 469 7 Reserved (always zero) 470 6 Adata 471 5 ... 3 M' 472 2 ... 0 L' 473 */ 474 475 static void btstack_crypto_ccm_setup_b_0(btstack_crypto_ccm_t * btstack_crypto_ccm, uint8_t * b0){ 476 uint8_t m_prime = (btstack_crypto_ccm->auth_len - 2) / 2; 477 uint8_t Adata = btstack_crypto_ccm->aad_len ? 1 : 0; 478 b0[0] = (Adata << 6) | (m_prime << 3) | 1 ; // Adata, M', L' = L - 1 479 (void)memcpy(&b0[1], btstack_crypto_ccm->nonce, 13); 480 big_endian_store_16(b0, 14, btstack_crypto_ccm->message_len); 481 #ifdef DEBUG_CCM 482 printf("%16s: ", "B0"); 483 printf_hexdump(b0, 16); 484 #endif 485 } 486 #endif 487 488 #ifdef ENABLE_ECC_P256 489 490 static void btstack_crypto_log_ec_publickey(const uint8_t * ec_q){ 491 log_info("Elliptic curve: X"); 492 log_info_hexdump(&ec_q[0],32); 493 log_info("Elliptic curve: Y"); 494 log_info_hexdump(&ec_q[32],32); 495 } 496 497 #if (defined(USE_MICRO_ECC_P256) && !defined(WICED_VERSION)) || defined(USE_MBEDTLS_ECC_P256) 498 // @return OK 499 static int sm_generate_f_rng(unsigned char * buffer, unsigned size){ 500 if (btstack_crypto_ecc_p256_key_generation_state != ECC_P256_KEY_GENERATION_ACTIVE) return 0; 501 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, btstack_crypto_ecc_p256_random_offset); 502 while (size) { 503 *buffer++ = btstack_crypto_ecc_p256_random[btstack_crypto_ecc_p256_random_offset++]; 504 size--; 505 } 506 return 1; 507 } 508 #endif 509 #ifdef USE_MBEDTLS_ECC_P256 510 // @return error - just wrap sm_generate_f_rng 511 static int sm_generate_f_rng_mbedtls(void * context, unsigned char * buffer, size_t size){ 512 UNUSED(context); 513 return sm_generate_f_rng(buffer, size) == 0; 514 } 515 #endif /* USE_MBEDTLS_ECC_P256 */ 516 517 static void btstack_crypto_ecc_p256_generate_key_software(void){ 518 519 btstack_crypto_ecc_p256_random_offset = 0; 520 521 // generate EC key 522 #ifdef USE_MICRO_ECC_P256 523 524 #ifndef WICED_VERSION 525 log_info("set uECC RNG for initial key generation with 64 random bytes"); 526 // micro-ecc from WICED SDK uses its wiced_crypto_get_random by default - no need to set it 527 uECC_set_rng(&sm_generate_f_rng); 528 #endif /* WICED_VERSION */ 529 530 #if uECC_SUPPORTS_secp256r1 531 // standard version 532 uECC_make_key(btstack_crypto_ecc_p256_public_key, btstack_crypto_ecc_p256_d, uECC_secp256r1()); 533 534 // disable RNG again, as returning no randmon data lets shared key generation fail 535 log_info("disable uECC RNG in standard version after key generation"); 536 uECC_set_rng(NULL); 537 #else 538 // static version 539 uECC_make_key(btstack_crypto_ecc_p256_public_key, btstack_crypto_ecc_p256_d); 540 #endif 541 #endif /* USE_MICRO_ECC_P256 */ 542 543 #ifdef USE_MBEDTLS_ECC_P256 544 mbedtls_mpi d; 545 mbedtls_ecp_point P; 546 mbedtls_mpi_init(&d); 547 mbedtls_ecp_point_init(&P); 548 int res = mbedtls_ecp_gen_keypair(&mbedtls_ec_group, &d, &P, &sm_generate_f_rng_mbedtls, NULL); 549 log_info("gen keypair %x", res); 550 mbedtls_mpi_write_binary(&P.X, &btstack_crypto_ecc_p256_public_key[0], 32); 551 mbedtls_mpi_write_binary(&P.Y, &btstack_crypto_ecc_p256_public_key[32], 32); 552 mbedtls_mpi_write_binary(&d, btstack_crypto_ecc_p256_d, 32); 553 mbedtls_ecp_point_free(&P); 554 mbedtls_mpi_free(&d); 555 #endif /* USE_MBEDTLS_ECC_P256 */ 556 } 557 558 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 559 static void btstack_crypto_ecc_p256_calculate_dhkey_software(btstack_crypto_ecc_p256_t * btstack_crypto_ec_p192){ 560 memset(btstack_crypto_ec_p192->dhkey, 0, 32); 561 562 #ifdef USE_MICRO_ECC_P256 563 #if uECC_SUPPORTS_secp256r1 564 // standard version 565 uECC_shared_secret(btstack_crypto_ec_p192->public_key, btstack_crypto_ecc_p256_d, btstack_crypto_ec_p192->dhkey, uECC_secp256r1()); 566 #else 567 // static version 568 uECC_shared_secret(btstack_crypto_ec_p192->public_key, btstack_crypto_ecc_p256_d, btstack_crypto_ec_p192->dhkey); 569 #endif 570 #endif 571 572 #ifdef USE_MBEDTLS_ECC_P256 573 // da * Pb 574 mbedtls_mpi d; 575 mbedtls_ecp_point Q; 576 mbedtls_ecp_point DH; 577 mbedtls_mpi_init(&d); 578 mbedtls_ecp_point_init(&Q); 579 mbedtls_ecp_point_init(&DH); 580 mbedtls_mpi_read_binary(&d, btstack_crypto_ecc_p256_d, 32); 581 mbedtls_mpi_read_binary(&Q.X, &btstack_crypto_ec_p192->public_key[0] , 32); 582 mbedtls_mpi_read_binary(&Q.Y, &btstack_crypto_ec_p192->public_key[32], 32); 583 mbedtls_mpi_lset(&Q.Z, 1); 584 mbedtls_ecp_mul(&mbedtls_ec_group, &DH, &d, &Q, NULL, NULL); 585 mbedtls_mpi_write_binary(&DH.X, btstack_crypto_ec_p192->dhkey, 32); 586 mbedtls_ecp_point_free(&DH); 587 mbedtls_mpi_free(&d); 588 mbedtls_ecp_point_free(&Q); 589 #endif 590 591 log_info("dhkey"); 592 log_info_hexdump(btstack_crypto_ec_p192->dhkey, 32); 593 } 594 #endif 595 596 #endif 597 598 #ifdef USE_BTSTACK_AES128 599 // CCM not implemented using software AES128 yet 600 #else 601 602 static void btstack_crypto_ccm_calc_s0(btstack_crypto_ccm_t * btstack_crypto_ccm){ 603 #ifdef DEBUG_CCM 604 printf("btstack_crypto_ccm_calc_s0\n"); 605 #endif 606 btstack_crypto_ccm->state = CCM_W4_S0; 607 btstack_crypto_ccm_setup_a_i(btstack_crypto_ccm, 0); 608 btstack_crypto_aes128_start(btstack_crypto_ccm->key, btstack_crypto_ccm_s); 609 } 610 611 static void btstack_crypto_ccm_calc_sn(btstack_crypto_ccm_t * btstack_crypto_ccm){ 612 #ifdef DEBUG_CCM 613 printf("btstack_crypto_ccm_calc_s%u\n", btstack_crypto_ccm->counter); 614 #endif 615 btstack_crypto_ccm->state = CCM_W4_SN; 616 btstack_crypto_ccm_setup_a_i(btstack_crypto_ccm, btstack_crypto_ccm->counter); 617 btstack_crypto_aes128_start(btstack_crypto_ccm->key, btstack_crypto_ccm_s); 618 } 619 620 static void btstack_crypto_ccm_calc_x1(btstack_crypto_ccm_t * btstack_crypto_ccm){ 621 uint8_t btstack_crypto_ccm_buffer[16]; 622 btstack_crypto_ccm->state = CCM_W4_X1; 623 btstack_crypto_ccm_setup_b_0(btstack_crypto_ccm, btstack_crypto_ccm_buffer); 624 btstack_crypto_aes128_start(btstack_crypto_ccm->key, btstack_crypto_ccm_buffer); 625 } 626 627 static void btstack_crypto_ccm_calc_xn(btstack_crypto_ccm_t * btstack_crypto_ccm, const uint8_t * plaintext){ 628 uint8_t btstack_crypto_ccm_buffer[16]; 629 btstack_crypto_ccm->state = CCM_W4_XN; 630 631 #ifdef DEBUG_CCM 632 printf("%16s: ", "bn"); 633 printf_hexdump(plaintext, 16); 634 #endif 635 uint8_t i; 636 uint8_t bytes_to_decrypt = btstack_crypto_ccm->block_len; 637 // use explicit min implementation as c-stat worried about out-of-bounds-reads 638 if (bytes_to_decrypt > 16) { 639 bytes_to_decrypt = 16; 640 } 641 for (i = 0; i < bytes_to_decrypt ; i++){ 642 btstack_crypto_ccm_buffer[i] = btstack_crypto_ccm->x_i[i] ^ plaintext[i]; 643 } 644 (void)memcpy(&btstack_crypto_ccm_buffer[i], &btstack_crypto_ccm->x_i[i], 645 16 - bytes_to_decrypt); 646 #ifdef DEBUG_CCM 647 printf("%16s: ", "Xn XOR bn"); 648 printf_hexdump(btstack_crypto_ccm_buffer, 16); 649 #endif 650 651 btstack_crypto_aes128_start(btstack_crypto_ccm->key, btstack_crypto_ccm_buffer); 652 } 653 654 static void btstack_crypto_ccm_calc_aad_xn(btstack_crypto_ccm_t * btstack_crypto_ccm){ 655 // store length 656 if (btstack_crypto_ccm->aad_offset == 0){ 657 uint8_t len_buffer[2]; 658 big_endian_store_16(len_buffer, 0, btstack_crypto_ccm->aad_len); 659 btstack_crypto_ccm->x_i[0] ^= len_buffer[0]; 660 btstack_crypto_ccm->x_i[1] ^= len_buffer[1]; 661 btstack_crypto_ccm->aad_remainder_len += 2; 662 btstack_crypto_ccm->aad_offset += 2; 663 } 664 665 // fill from input 666 uint16_t bytes_free = 16 - btstack_crypto_ccm->aad_remainder_len; 667 uint16_t bytes_to_copy = btstack_min(bytes_free, btstack_crypto_ccm->block_len); 668 while (bytes_to_copy){ 669 btstack_crypto_ccm->x_i[btstack_crypto_ccm->aad_remainder_len++] ^= *btstack_crypto_ccm->input++; 670 btstack_crypto_ccm->aad_offset++; 671 btstack_crypto_ccm->block_len--; 672 bytes_to_copy--; 673 bytes_free--; 674 } 675 676 // if last block, fill with zeros 677 if (btstack_crypto_ccm->aad_offset == (btstack_crypto_ccm->aad_len + 2)){ 678 btstack_crypto_ccm->aad_remainder_len = 16; 679 } 680 // if not full, notify done 681 if (btstack_crypto_ccm->aad_remainder_len < 16){ 682 btstack_crypto_done(&btstack_crypto_ccm->btstack_crypto); 683 return; 684 } 685 686 // encrypt block 687 #ifdef DEBUG_CCM 688 printf("%16s: ", "Xn XOR Bn (aad)"); 689 printf_hexdump(btstack_crypto_ccm->x_i, 16); 690 #endif 691 692 btstack_crypto_ccm->aad_remainder_len = 0; 693 btstack_crypto_ccm->state = CCM_W4_AAD_XN; 694 btstack_crypto_aes128_start(btstack_crypto_ccm->key, btstack_crypto_ccm->x_i); 695 } 696 697 static void btstack_crypto_ccm_handle_s0(btstack_crypto_ccm_t * btstack_crypto_ccm, const uint8_t * data){ 698 // data is little-endian, flip on the fly 699 int i; 700 for (i=0;i<16;i++){ 701 btstack_crypto_ccm->x_i[i] = btstack_crypto_ccm->x_i[i] ^ data[15-i]; 702 } 703 btstack_crypto_done(&btstack_crypto_ccm->btstack_crypto); 704 } 705 706 static void btstack_crypto_ccm_handle_sn(btstack_crypto_ccm_t * btstack_crypto_ccm, const uint8_t * data){ 707 // data is little-endian, flip on the fly 708 int i; 709 uint16_t bytes_to_process = btstack_min(btstack_crypto_ccm->block_len, 16); 710 for (i=0;i<bytes_to_process;i++){ 711 btstack_crypto_ccm->output[i] = btstack_crypto_ccm->input[i] ^ data[15-i]; 712 } 713 } 714 715 static void btstack_crypto_ccm_next_block(btstack_crypto_ccm_t * btstack_crypto_ccm, btstack_crypto_ccm_state_t state_when_done){ 716 uint16_t bytes_to_process = btstack_min(btstack_crypto_ccm->block_len, 16); 717 // next block 718 btstack_crypto_ccm->counter++; 719 btstack_crypto_ccm->input += bytes_to_process; 720 btstack_crypto_ccm->output += bytes_to_process; 721 btstack_crypto_ccm->block_len -= bytes_to_process; 722 btstack_crypto_ccm->message_len -= bytes_to_process; 723 #ifdef DEBUG_CCM 724 printf("btstack_crypto_ccm_next_block (message len %u, block_len %u)\n", btstack_crypto_ccm->message_len, btstack_crypto_ccm->block_len); 725 #endif 726 if (btstack_crypto_ccm->message_len == 0){ 727 btstack_crypto_ccm->state = CCM_CALCULATE_S0; 728 } else { 729 btstack_crypto_ccm->state = state_when_done; 730 if (btstack_crypto_ccm->block_len == 0){ 731 btstack_crypto_done(&btstack_crypto_ccm->btstack_crypto); 732 } 733 } 734 } 735 #endif 736 737 static void btstack_crypto_run(void){ 738 739 btstack_crypto_aes128_t * btstack_crypto_aes128; 740 btstack_crypto_ccm_t * btstack_crypto_ccm; 741 btstack_crypto_aes128_cmac_t * btstack_crypto_cmac; 742 #ifdef ENABLE_ECC_P256 743 btstack_crypto_ecc_p256_t * btstack_crypto_ec_p192; 744 #endif 745 746 // stack up and running? 747 if (hci_get_state() != HCI_STATE_WORKING) return; 748 749 // try to do as much as possible 750 while (true){ 751 752 // anything to do? 753 if (btstack_linked_list_empty(&btstack_crypto_operations)) return; 754 755 // already active? 756 if (btstack_crypto_wait_for_hci_result) return; 757 758 // can send a command? 759 if (!hci_can_send_command_packet_now()) return; 760 761 // ok, find next task 762 btstack_crypto_t * btstack_crypto = (btstack_crypto_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 763 switch (btstack_crypto->operation){ 764 case BTSTACK_CRYPTO_RANDOM: 765 btstack_crypto_wait_for_hci_result = 1; 766 hci_send_cmd(&hci_le_rand); 767 break; 768 case BTSTACK_CRYPTO_AES128: 769 btstack_crypto_aes128 = (btstack_crypto_aes128_t *) btstack_crypto; 770 #ifdef USE_BTSTACK_AES128 771 btstack_aes128_calc(btstack_crypto_aes128->key, btstack_crypto_aes128->plaintext, btstack_crypto_aes128->ciphertext); 772 btstack_crypto_done(btstack_crypto); 773 #else 774 btstack_crypto_aes128_start(btstack_crypto_aes128->key, btstack_crypto_aes128->plaintext); 775 #endif 776 break; 777 778 case BTSTACK_CRYPTO_CMAC_MESSAGE: 779 case BTSTACK_CRYPTO_CMAC_GENERATOR: 780 btstack_crypto_cmac = (btstack_crypto_aes128_cmac_t *) btstack_crypto; 781 #ifdef USE_BTSTACK_AES128 782 btstack_crypto_cmac_calc( btstack_crypto_cmac ); 783 btstack_crypto_done(btstack_crypto); 784 #else 785 btstack_crypto_wait_for_hci_result = 1; 786 if (btstack_crypto_cmac_state == CMAC_IDLE){ 787 btstack_crypto_cmac_start(btstack_crypto_cmac); 788 } else { 789 btstack_crypto_cmac_handle_aes_engine_ready(btstack_crypto_cmac); 790 } 791 #endif 792 break; 793 794 case BTSTACK_CRYPTO_CCM_DIGEST_BLOCK: 795 case BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK: 796 case BTSTACK_CRYPTO_CCM_DECRYPT_BLOCK: 797 #ifdef USE_BTSTACK_AES128 798 UNUSED(btstack_crypto_ccm); 799 // NOTE: infinite output of this message 800 log_error("ccm not implemented for software aes128 yet"); 801 #else 802 btstack_crypto_ccm = (btstack_crypto_ccm_t *) btstack_crypto; 803 switch (btstack_crypto_ccm->state){ 804 case CCM_CALCULATE_AAD_XN: 805 btstack_crypto_ccm_calc_aad_xn(btstack_crypto_ccm); 806 break; 807 case CCM_CALCULATE_X1: 808 btstack_crypto_ccm_calc_x1(btstack_crypto_ccm); 809 break; 810 case CCM_CALCULATE_S0: 811 btstack_crypto_ccm_calc_s0(btstack_crypto_ccm); 812 break; 813 case CCM_CALCULATE_SN: 814 btstack_crypto_ccm_calc_sn(btstack_crypto_ccm); 815 break; 816 case CCM_CALCULATE_XN: 817 btstack_crypto_ccm_calc_xn(btstack_crypto_ccm, (btstack_crypto->operation == BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK) ? btstack_crypto_ccm->input : btstack_crypto_ccm->output); 818 break; 819 default: 820 break; 821 } 822 #endif 823 break; 824 825 #ifdef ENABLE_ECC_P256 826 case BTSTACK_CRYPTO_ECC_P256_GENERATE_KEY: 827 btstack_crypto_ec_p192 = (btstack_crypto_ecc_p256_t *) btstack_crypto; 828 switch (btstack_crypto_ecc_p256_key_generation_state){ 829 case ECC_P256_KEY_GENERATION_DONE: 830 // done 831 btstack_crypto_log_ec_publickey(btstack_crypto_ecc_p256_public_key); 832 (void)memcpy(btstack_crypto_ec_p192->public_key, 833 btstack_crypto_ecc_p256_public_key, 64); 834 btstack_linked_list_pop(&btstack_crypto_operations); 835 (*btstack_crypto_ec_p192->btstack_crypto.context_callback.callback)(btstack_crypto_ec_p192->btstack_crypto.context_callback.context); 836 break; 837 case ECC_P256_KEY_GENERATION_IDLE: 838 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 839 log_info("start ecc random"); 840 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_GENERATING_RANDOM; 841 btstack_crypto_ecc_p256_random_offset = 0; 842 btstack_crypto_wait_for_hci_result = 1; 843 hci_send_cmd(&hci_le_rand); 844 #else 845 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_W4_KEY; 846 btstack_crypto_wait_for_hci_result = 1; 847 hci_send_cmd(&hci_le_read_local_p256_public_key); 848 #endif 849 break; 850 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 851 case ECC_P256_KEY_GENERATION_GENERATING_RANDOM: 852 log_info("more ecc random"); 853 btstack_crypto_wait_for_hci_result = 1; 854 hci_send_cmd(&hci_le_rand); 855 break; 856 #endif 857 default: 858 break; 859 } 860 break; 861 case BTSTACK_CRYPTO_ECC_P256_CALCULATE_DHKEY: 862 btstack_crypto_ec_p192 = (btstack_crypto_ecc_p256_t *) btstack_crypto; 863 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 864 btstack_crypto_ecc_p256_calculate_dhkey_software(btstack_crypto_ec_p192); 865 // done 866 btstack_linked_list_pop(&btstack_crypto_operations); 867 (*btstack_crypto_ec_p192->btstack_crypto.context_callback.callback)(btstack_crypto_ec_p192->btstack_crypto.context_callback.context); 868 #else 869 btstack_crypto_wait_for_hci_result = 1; 870 hci_send_cmd(&hci_le_generate_dhkey, &btstack_crypto_ec_p192->public_key[0], &btstack_crypto_ec_p192->public_key[32]); 871 #endif 872 break; 873 874 #endif /* ENABLE_ECC_P256 */ 875 876 default: 877 break; 878 } 879 } 880 } 881 882 static void btstack_crypto_handle_random_data(const uint8_t * data, uint16_t len){ 883 btstack_crypto_random_t * btstack_crypto_random; 884 btstack_crypto_t * btstack_crypto = (btstack_crypto_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 885 uint16_t bytes_to_copy; 886 if (!btstack_crypto) return; 887 switch (btstack_crypto->operation){ 888 case BTSTACK_CRYPTO_RANDOM: 889 btstack_crypto_random = (btstack_crypto_random_t*) btstack_crypto; 890 bytes_to_copy = btstack_min(btstack_crypto_random->size, len); 891 (void)memcpy(btstack_crypto_random->buffer, data, bytes_to_copy); 892 btstack_crypto_random->buffer += bytes_to_copy; 893 btstack_crypto_random->size -= bytes_to_copy; 894 // data processed, more? 895 if (!btstack_crypto_random->size) { 896 // done 897 btstack_linked_list_pop(&btstack_crypto_operations); 898 (*btstack_crypto_random->btstack_crypto.context_callback.callback)(btstack_crypto_random->btstack_crypto.context_callback.context); 899 } 900 break; 901 #ifdef ENABLE_ECC_P256 902 case BTSTACK_CRYPTO_ECC_P256_GENERATE_KEY: 903 (void)memcpy(&btstack_crypto_ecc_p256_random[btstack_crypto_ecc_p256_random_len], 904 data, 8); 905 btstack_crypto_ecc_p256_random_len += 8; 906 if (btstack_crypto_ecc_p256_random_len >= 64) { 907 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_ACTIVE; 908 btstack_crypto_ecc_p256_generate_key_software(); 909 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_DONE; 910 } 911 break; 912 #endif 913 default: 914 break; 915 } 916 // more work? 917 btstack_crypto_run(); 918 } 919 920 #ifndef USE_BTSTACK_AES128 921 static void btstack_crypto_handle_encryption_result(const uint8_t * data){ 922 btstack_crypto_aes128_t * btstack_crypto_aes128; 923 btstack_crypto_aes128_cmac_t * btstack_crypto_cmac; 924 btstack_crypto_ccm_t * btstack_crypto_ccm; 925 uint8_t result[16]; 926 927 btstack_crypto_t * btstack_crypto = (btstack_crypto_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 928 if (!btstack_crypto) return; 929 switch (btstack_crypto->operation){ 930 case BTSTACK_CRYPTO_AES128: 931 btstack_crypto_aes128 = (btstack_crypto_aes128_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 932 reverse_128(data, btstack_crypto_aes128->ciphertext); 933 btstack_crypto_done(btstack_crypto); 934 break; 935 case BTSTACK_CRYPTO_CMAC_GENERATOR: 936 case BTSTACK_CRYPTO_CMAC_MESSAGE: 937 btstack_crypto_cmac = (btstack_crypto_aes128_cmac_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 938 reverse_128(data, result); 939 btstack_crypto_cmac_handle_encryption_result(btstack_crypto_cmac, result); 940 break; 941 case BTSTACK_CRYPTO_CCM_DIGEST_BLOCK: 942 btstack_crypto_ccm = (btstack_crypto_ccm_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 943 switch (btstack_crypto_ccm->state){ 944 case CCM_W4_X1: 945 reverse_128(data, btstack_crypto_ccm->x_i); 946 #ifdef DEBUG_CCM 947 printf("%16s: ", "X1"); 948 printf_hexdump(btstack_crypto_ccm->x_i, 16); 949 #endif 950 btstack_crypto_ccm->aad_remainder_len = 0; 951 btstack_crypto_ccm->state = CCM_CALCULATE_AAD_XN; 952 break; 953 case CCM_W4_AAD_XN: 954 reverse_128(data, btstack_crypto_ccm->x_i); 955 #ifdef DEBUG_CCM 956 printf("%16s: ", "Xn+1 AAD"); 957 printf_hexdump(btstack_crypto_ccm->x_i, 16); 958 #endif 959 // more aad? 960 if (btstack_crypto_ccm->aad_offset < (btstack_crypto_ccm->aad_len + 2)){ 961 btstack_crypto_ccm->state = CCM_CALCULATE_AAD_XN; 962 } else { 963 // done 964 btstack_crypto_done(btstack_crypto); 965 } 966 break; 967 default: 968 break; 969 } 970 break; 971 case BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK: 972 btstack_crypto_ccm = (btstack_crypto_ccm_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 973 switch (btstack_crypto_ccm->state){ 974 case CCM_W4_X1: 975 reverse_128(data, btstack_crypto_ccm->x_i); 976 #ifdef DEBUG_CCM 977 printf("%16s: ", "X1"); 978 printf_hexdump(btstack_crypto_ccm->x_i, 16); 979 #endif 980 btstack_crypto_ccm->state = CCM_CALCULATE_XN; 981 break; 982 case CCM_W4_XN: 983 reverse_128(data, btstack_crypto_ccm->x_i); 984 #ifdef DEBUG_CCM 985 printf("%16s: ", "Xn+1"); 986 printf_hexdump(btstack_crypto_ccm->x_i, 16); 987 #endif 988 btstack_crypto_ccm->state = CCM_CALCULATE_SN; 989 break; 990 case CCM_W4_S0: 991 #ifdef DEBUG_CCM 992 reverse_128(data, result); 993 printf("%16s: ", "X0"); 994 printf_hexdump(btstack_crypto_ccm->x_i, 16); 995 #endif 996 btstack_crypto_ccm_handle_s0(btstack_crypto_ccm, data); 997 break; 998 case CCM_W4_SN: 999 #ifdef DEBUG_CCM 1000 reverse_128(data, result); 1001 printf("%16s: ", "Sn"); 1002 printf_hexdump(btstack_crypto_ccm->x_i, 16); 1003 #endif 1004 btstack_crypto_ccm_handle_sn(btstack_crypto_ccm, data); 1005 btstack_crypto_ccm_next_block(btstack_crypto_ccm, CCM_CALCULATE_XN); 1006 break; 1007 default: 1008 break; 1009 } 1010 break; 1011 case BTSTACK_CRYPTO_CCM_DECRYPT_BLOCK: 1012 btstack_crypto_ccm = (btstack_crypto_ccm_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 1013 switch (btstack_crypto_ccm->state){ 1014 case CCM_W4_X1: 1015 reverse_128(data, btstack_crypto_ccm->x_i); 1016 #ifdef DEBUG_CCM 1017 printf("%16s: ", "X1"); 1018 printf_hexdump(btstack_crypto_ccm->x_i, 16); 1019 #endif 1020 btstack_crypto_ccm->state = CCM_CALCULATE_SN; 1021 break; 1022 case CCM_W4_XN: 1023 reverse_128(data, btstack_crypto_ccm->x_i); 1024 #ifdef DEBUG_CCM 1025 printf("%16s: ", "Xn+1"); 1026 printf_hexdump(btstack_crypto_ccm->x_i, 16); 1027 #endif 1028 btstack_crypto_ccm_next_block(btstack_crypto_ccm, CCM_CALCULATE_SN); 1029 break; 1030 case CCM_W4_S0: 1031 btstack_crypto_ccm_handle_s0(btstack_crypto_ccm, data); 1032 break; 1033 case CCM_W4_SN: 1034 btstack_crypto_ccm_handle_sn(btstack_crypto_ccm, data); 1035 btstack_crypto_ccm->state = CCM_CALCULATE_XN; 1036 break; 1037 default: 1038 break; 1039 } 1040 break; 1041 default: 1042 break; 1043 } 1044 } 1045 #endif 1046 1047 static void btstack_crypto_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1048 UNUSED(cid); // ok: there is no channel 1049 UNUSED(size); // ok: fixed format events read from HCI buffer 1050 1051 #ifdef ENABLE_ECC_P256 1052 #ifndef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 1053 btstack_crypto_ecc_p256_t * btstack_crypto_ec_p192; 1054 #endif 1055 #endif 1056 1057 if (packet_type != HCI_EVENT_PACKET) return; 1058 1059 switch (hci_event_packet_get_type(packet)){ 1060 case BTSTACK_EVENT_STATE: 1061 log_info("BTSTACK_EVENT_STATE"); 1062 if (btstack_event_state_get_state(packet) != HCI_STATE_HALTING) break; 1063 if (!btstack_crypto_wait_for_hci_result) break; 1064 // request stack to defer shutdown a bit 1065 hci_halting_defer(); 1066 break; 1067 1068 case HCI_EVENT_COMMAND_COMPLETE: 1069 #ifndef USE_BTSTACK_AES128 1070 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 1071 if (!btstack_crypto_wait_for_hci_result) return; 1072 btstack_crypto_wait_for_hci_result = 0; 1073 btstack_crypto_handle_encryption_result(&packet[6]); 1074 } 1075 #endif 1076 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 1077 if (!btstack_crypto_wait_for_hci_result) return; 1078 btstack_crypto_wait_for_hci_result = 0; 1079 btstack_crypto_handle_random_data(&packet[6], 8); 1080 } 1081 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_local_supported_commands)){ 1082 int ecdh_operations_supported = (packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+34] & 0x06) == 0x06; 1083 log_info("controller supports ECDH operation: %u", ecdh_operations_supported); 1084 #ifdef ENABLE_ECC_P256 1085 #ifndef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 1086 if (!ecdh_operations_supported){ 1087 // mbedTLS can also be used if already available (and malloc is supported) 1088 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"); 1089 } 1090 #endif 1091 #endif 1092 } 1093 break; 1094 1095 #ifdef ENABLE_ECC_P256 1096 #ifndef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 1097 case HCI_EVENT_LE_META: 1098 btstack_crypto_ec_p192 = (btstack_crypto_ecc_p256_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 1099 if (!btstack_crypto_ec_p192) break; 1100 switch (hci_event_le_meta_get_subevent_code(packet)){ 1101 case HCI_SUBEVENT_LE_READ_LOCAL_P256_PUBLIC_KEY_COMPLETE: 1102 if (btstack_crypto_ec_p192->btstack_crypto.operation != BTSTACK_CRYPTO_ECC_P256_GENERATE_KEY) break; 1103 if (!btstack_crypto_wait_for_hci_result) return; 1104 btstack_crypto_wait_for_hci_result = 0; 1105 if (hci_subevent_le_read_local_p256_public_key_complete_get_status(packet)){ 1106 log_error("Read Local P256 Public Key failed"); 1107 } 1108 hci_subevent_le_read_local_p256_public_key_complete_get_dhkey_x(packet, &btstack_crypto_ecc_p256_public_key[0]); 1109 hci_subevent_le_read_local_p256_public_key_complete_get_dhkey_y(packet, &btstack_crypto_ecc_p256_public_key[32]); 1110 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_DONE; 1111 break; 1112 case HCI_SUBEVENT_LE_GENERATE_DHKEY_COMPLETE: 1113 if (btstack_crypto_ec_p192->btstack_crypto.operation != BTSTACK_CRYPTO_ECC_P256_CALCULATE_DHKEY) break; 1114 if (!btstack_crypto_wait_for_hci_result) return; 1115 btstack_crypto_wait_for_hci_result = 0; 1116 if (hci_subevent_le_generate_dhkey_complete_get_status(packet)){ 1117 log_error("Generate DHKEY failed -> abort"); 1118 } 1119 hci_subevent_le_generate_dhkey_complete_get_dhkey(packet, btstack_crypto_ec_p192->dhkey); 1120 // done 1121 btstack_linked_list_pop(&btstack_crypto_operations); 1122 (*btstack_crypto_ec_p192->btstack_crypto.context_callback.callback)(btstack_crypto_ec_p192->btstack_crypto.context_callback.context); 1123 break; 1124 default: 1125 break; 1126 } 1127 break; 1128 #endif 1129 #endif 1130 default: 1131 break; 1132 } 1133 1134 // try processing 1135 btstack_crypto_run(); 1136 } 1137 1138 void btstack_crypto_init(void){ 1139 if (btstack_crypto_initialized) return; 1140 btstack_crypto_initialized = 1; 1141 1142 // register with HCI 1143 hci_event_callback_registration.callback = &btstack_crypto_event_handler; 1144 hci_add_event_handler(&hci_event_callback_registration); 1145 1146 #ifdef USE_MBEDTLS_ECC_P256 1147 mbedtls_ecp_group_init(&mbedtls_ec_group); 1148 mbedtls_ecp_group_load(&mbedtls_ec_group, MBEDTLS_ECP_DP_SECP256R1); 1149 #endif 1150 } 1151 1152 void btstack_crypto_random_generate(btstack_crypto_random_t * request, uint8_t * buffer, uint16_t size, void (* callback)(void * arg), void * callback_arg){ 1153 request->btstack_crypto.context_callback.callback = callback; 1154 request->btstack_crypto.context_callback.context = callback_arg; 1155 request->btstack_crypto.operation = BTSTACK_CRYPTO_RANDOM; 1156 request->buffer = buffer; 1157 request->size = size; 1158 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1159 btstack_crypto_run(); 1160 } 1161 1162 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){ 1163 request->btstack_crypto.context_callback.callback = callback; 1164 request->btstack_crypto.context_callback.context = callback_arg; 1165 request->btstack_crypto.operation = BTSTACK_CRYPTO_AES128; 1166 request->key = key; 1167 request->plaintext = plaintext; 1168 request->ciphertext = ciphertext; 1169 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1170 btstack_crypto_run(); 1171 } 1172 1173 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){ 1174 request->btstack_crypto.context_callback.callback = callback; 1175 request->btstack_crypto.context_callback.context = callback_arg; 1176 request->btstack_crypto.operation = BTSTACK_CRYPTO_CMAC_GENERATOR; 1177 request->key = key; 1178 request->size = size; 1179 request->data.get_byte_callback = get_byte_callback; 1180 request->hash = hash; 1181 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1182 btstack_crypto_run(); 1183 } 1184 1185 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){ 1186 request->btstack_crypto.context_callback.callback = callback; 1187 request->btstack_crypto.context_callback.context = callback_arg; 1188 request->btstack_crypto.operation = BTSTACK_CRYPTO_CMAC_MESSAGE; 1189 request->key = key; 1190 request->size = size; 1191 request->data.message = message; 1192 request->hash = hash; 1193 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1194 btstack_crypto_run(); 1195 } 1196 1197 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){ 1198 request->btstack_crypto.context_callback.callback = callback; 1199 request->btstack_crypto.context_callback.context = callback_arg; 1200 request->btstack_crypto.operation = BTSTACK_CRYPTO_CMAC_MESSAGE; 1201 request->key = zero; 1202 request->size = len; 1203 request->data.message = message; 1204 request->hash = hash; 1205 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1206 btstack_crypto_run(); 1207 } 1208 1209 #ifdef ENABLE_ECC_P256 1210 void btstack_crypto_ecc_p256_generate_key(btstack_crypto_ecc_p256_t * request, uint8_t * public_key, void (* callback)(void * arg), void * callback_arg){ 1211 // reset key generation 1212 if (btstack_crypto_ecc_p256_key_generation_state == ECC_P256_KEY_GENERATION_DONE){ 1213 btstack_crypto_ecc_p256_random_len = 0; 1214 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_IDLE; 1215 } 1216 request->btstack_crypto.context_callback.callback = callback; 1217 request->btstack_crypto.context_callback.context = callback_arg; 1218 request->btstack_crypto.operation = BTSTACK_CRYPTO_ECC_P256_GENERATE_KEY; 1219 request->public_key = public_key; 1220 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1221 btstack_crypto_run(); 1222 } 1223 1224 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){ 1225 request->btstack_crypto.context_callback.callback = callback; 1226 request->btstack_crypto.context_callback.context = callback_arg; 1227 request->btstack_crypto.operation = BTSTACK_CRYPTO_ECC_P256_CALCULATE_DHKEY; 1228 request->public_key = (uint8_t *) public_key; 1229 request->dhkey = dhkey; 1230 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1231 btstack_crypto_run(); 1232 } 1233 1234 int btstack_crypto_ecc_p256_validate_public_key(const uint8_t * public_key){ 1235 1236 // validate public key using micro-ecc 1237 int err = 0; 1238 1239 #ifdef USE_MICRO_ECC_P256 1240 #if uECC_SUPPORTS_secp256r1 1241 // standard version 1242 err = uECC_valid_public_key(public_key, uECC_secp256r1()) == 0; 1243 #else 1244 // static version 1245 err = uECC_valid_public_key(public_key) == 0; 1246 #endif 1247 #endif 1248 1249 #ifdef USE_MBEDTLS_ECC_P256 1250 mbedtls_ecp_point Q; 1251 mbedtls_ecp_point_init( &Q ); 1252 mbedtls_mpi_read_binary(&Q.X, &public_key[0], 32); 1253 mbedtls_mpi_read_binary(&Q.Y, &public_key[32], 32); 1254 mbedtls_mpi_lset(&Q.Z, 1); 1255 err = mbedtls_ecp_check_pubkey(&mbedtls_ec_group, &Q); 1256 mbedtls_ecp_point_free( & Q); 1257 #endif 1258 1259 if (err){ 1260 log_error("public key invalid %x", err); 1261 } 1262 return err; 1263 } 1264 #endif 1265 1266 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){ 1267 request->key = key; 1268 request->nonce = nonce; 1269 request->message_len = message_len; 1270 request->aad_len = additional_authenticated_data_len; 1271 request->aad_offset = 0; 1272 request->auth_len = auth_len; 1273 request->counter = 1; 1274 request->state = CCM_CALCULATE_X1; 1275 } 1276 1277 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){ 1278 // not implemented yet 1279 request->btstack_crypto.context_callback.callback = callback; 1280 request->btstack_crypto.context_callback.context = callback_arg; 1281 request->btstack_crypto.operation = BTSTACK_CRYPTO_CCM_DIGEST_BLOCK; 1282 request->block_len = additional_authenticated_data_len; 1283 request->input = additional_authenticated_data; 1284 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1285 btstack_crypto_run(); 1286 } 1287 1288 void btstack_crypto_ccm_get_authentication_value(btstack_crypto_ccm_t * request, uint8_t * authentication_value){ 1289 (void)memcpy(authentication_value, request->x_i, request->auth_len); 1290 } 1291 1292 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){ 1293 #ifdef DEBUG_CCM 1294 printf("\nbtstack_crypto_ccm_encrypt_block, len %u\n", block_len); 1295 #endif 1296 request->btstack_crypto.context_callback.callback = callback; 1297 request->btstack_crypto.context_callback.context = callback_arg; 1298 request->btstack_crypto.operation = BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK; 1299 request->block_len = block_len; 1300 request->input = plaintext; 1301 request->output = ciphertext; 1302 if (request->state != CCM_CALCULATE_X1){ 1303 request->state = CCM_CALCULATE_XN; 1304 } 1305 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1306 btstack_crypto_run(); 1307 } 1308 1309 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){ 1310 request->btstack_crypto.context_callback.callback = callback; 1311 request->btstack_crypto.context_callback.context = callback_arg; 1312 request->btstack_crypto.operation = BTSTACK_CRYPTO_CCM_DECRYPT_BLOCK; 1313 request->block_len = block_len; 1314 request->input = ciphertext; 1315 request->output = plaintext; 1316 if (request->state != CCM_CALCULATE_X1){ 1317 request->state = CCM_CALCULATE_SN; 1318 } 1319 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1320 btstack_crypto_run(); 1321 } 1322 1323 // PTS only 1324 void btstack_crypto_ecc_p256_set_key(const uint8_t * public_key, const uint8_t * private_key){ 1325 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 1326 (void)memcpy(btstack_crypto_ecc_p256_d, private_key, 32); 1327 (void)memcpy(btstack_crypto_ecc_p256_public_key, public_key, 64); 1328 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_DONE; 1329 #else 1330 UNUSED(public_key); 1331 UNUSED(private_key); 1332 #endif 1333 } 1334 // Unit testing 1335 int btstack_crypto_idle(void){ 1336 return btstack_linked_list_empty(&btstack_crypto_operations); 1337 } 1338 void btstack_crypto_reset(void){ 1339 btstack_crypto_operations = NULL; 1340 btstack_crypto_wait_for_hci_result = 0; 1341 } 1342