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 // backwards-compatitility ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS -> ENABLE_MICRO_ECC_P256 50 #if defined(ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS) && !defined(ENABLE_MICRO_ECC_P256) 51 #define ENABLE_MICRO_ECC_P256 52 #endif 53 54 // configure ECC implementations 55 #if defined(ENABLE_MICRO_ECC_P256) && defined(HAVE_MBEDTLS_ECC_P256) 56 #error "If you have mbedTLS (HAVE_MBEDTLS_ECC_P256), please disable uECC (ENABLE_MICRO_ECC_P256) in bstack_config.h" 57 #endif 58 59 // Software ECC-P256 implementation provided by micro-ecc 60 #ifdef ENABLE_MICRO_ECC_P256 61 #define ENABLE_ECC_P256 62 #define USE_MICRO_ECC_P256 63 #define USE_SOFTWARE_ECC_P256_IMPLEMENTATION 64 #include "uECC.h" 65 #endif 66 67 // Software ECC-P256 implementation provided by mbedTLS 68 #ifdef HAVE_MBEDTLS_ECC_P256 69 #define ENABLE_ECC_P256 70 #define USE_MBEDTLS_ECC_P256 71 #define USE_SOFTWARE_ECC_P256_IMPLEMENTATION 72 #include "mbedtls/config.h" 73 #include "mbedtls/platform.h" 74 #include "mbedtls/ecp.h" 75 #endif 76 77 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(ENABLE_ECC_P256) 78 #define ENABLE_ECC_P256 79 #endif 80 81 // Software AES128 82 #ifdef HAVE_AES128 83 #define USE_BTSTACK_AES128 84 void btstack_aes128_calc(const uint8_t * key, const uint8_t * plaintext, uint8_t * result); 85 #endif 86 87 // degbugging 88 // #define DEBUG_CCM 89 90 typedef enum { 91 CMAC_IDLE, 92 CMAC_CALC_SUBKEYS, 93 CMAC_W4_SUBKEYS, 94 CMAC_CALC_MI, 95 CMAC_W4_MI, 96 CMAC_CALC_MLAST, 97 CMAC_W4_MLAST 98 } btstack_crypto_cmac_state_t; 99 100 typedef enum { 101 ECC_P256_KEY_GENERATION_IDLE, 102 ECC_P256_KEY_GENERATION_GENERATING_RANDOM, 103 ECC_P256_KEY_GENERATION_ACTIVE, 104 ECC_P256_KEY_GENERATION_W4_KEY, 105 ECC_P256_KEY_GENERATION_DONE, 106 } btstack_crypto_ecc_p256_key_generation_state_t; 107 108 static void btstack_crypto_run(void); 109 110 static const uint8_t zero[16] = { 0 }; 111 112 static uint8_t btstack_crypto_initialized; 113 static btstack_linked_list_t btstack_crypto_operations; 114 static btstack_packet_callback_registration_t hci_event_callback_registration; 115 static uint8_t btstack_crypto_wait_for_hci_result; 116 117 // state for AES-CMAC 118 static btstack_crypto_cmac_state_t btstack_crypto_cmac_state; 119 static sm_key_t btstack_crypto_cmac_k; 120 static sm_key_t btstack_crypto_cmac_x; 121 static sm_key_t btstack_crypto_cmac_m_last; 122 static uint8_t btstack_crypto_cmac_block_current; 123 static uint8_t btstack_crypto_cmac_block_count; 124 125 // state for AES-CCM 126 #ifndef USE_BTSTACK_AES128 127 static uint8_t btstack_crypto_ccm_s[16]; 128 #endif 129 130 #ifdef ENABLE_ECC_P256 131 132 static uint8_t btstack_crypto_ecc_p256_public_key[64]; 133 static uint8_t btstack_crypto_ecc_p256_random[64]; 134 static uint8_t btstack_crypto_ecc_p256_random_len; 135 static uint8_t btstack_crypto_ecc_p256_random_offset; 136 static btstack_crypto_ecc_p256_key_generation_state_t btstack_crypto_ecc_p256_key_generation_state; 137 138 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 139 static uint8_t btstack_crypto_ecc_p256_d[32]; 140 #endif 141 142 // Software ECDH implementation provided by mbedtls 143 #ifdef USE_MBEDTLS_ECC_P256 144 static mbedtls_ecp_group mbedtls_ec_group; 145 #endif 146 147 #endif /* ENABLE_ECC_P256 */ 148 149 static void btstack_crypto_done(btstack_crypto_t * btstack_crypto){ 150 btstack_linked_list_pop(&btstack_crypto_operations); 151 (*btstack_crypto->context_callback.callback)(btstack_crypto->context_callback.context); 152 } 153 154 static inline void btstack_crypto_cmac_next_state(void){ 155 btstack_crypto_cmac_state = (btstack_crypto_cmac_state_t) (((int)btstack_crypto_cmac_state) + 1); 156 } 157 158 static int btstack_crypto_cmac_last_block_complete(btstack_crypto_aes128_cmac_t * btstack_crypto_cmac){ 159 uint16_t len = btstack_crypto_cmac->size; 160 if (len == 0) return 0; 161 return (len & 0x0f) == 0; 162 } 163 164 static void btstack_crypto_aes128_start(const sm_key_t key, const sm_key_t plaintext){ 165 uint8_t key_flipped[16]; 166 uint8_t plaintext_flipped[16]; 167 reverse_128(key, key_flipped); 168 reverse_128(plaintext, plaintext_flipped); 169 btstack_crypto_wait_for_hci_result = 1; 170 hci_send_cmd(&hci_le_encrypt, key_flipped, plaintext_flipped); 171 } 172 173 static uint8_t btstack_crypto_cmac_get_byte(btstack_crypto_aes128_cmac_t * btstack_crypto_cmac, uint16_t pos){ 174 if (btstack_crypto_cmac->btstack_crypto.operation == BTSTACK_CRYPTO_CMAC_GENERATOR){ 175 return (*btstack_crypto_cmac->data.get_byte_callback)(pos); 176 } else { 177 return btstack_crypto_cmac->data.message[pos]; 178 } 179 } 180 181 static void btstack_crypto_cmac_handle_aes_engine_ready(btstack_crypto_aes128_cmac_t * btstack_crypto_cmac){ 182 switch (btstack_crypto_cmac_state){ 183 case CMAC_CALC_SUBKEYS: { 184 sm_key_t const_zero; 185 memset(const_zero, 0, 16); 186 btstack_crypto_cmac_next_state(); 187 btstack_crypto_aes128_start(btstack_crypto_cmac_k, const_zero); 188 break; 189 } 190 case CMAC_CALC_MI: { 191 int j; 192 sm_key_t y; 193 for (j=0;j<16;j++){ 194 y[j] = btstack_crypto_cmac_x[j] ^ btstack_crypto_cmac_get_byte(btstack_crypto_cmac, (btstack_crypto_cmac_block_current*16) + j); 195 } 196 btstack_crypto_cmac_block_current++; 197 btstack_crypto_cmac_next_state(); 198 btstack_crypto_aes128_start(btstack_crypto_cmac_k, y); 199 break; 200 } 201 case CMAC_CALC_MLAST: { 202 int i; 203 sm_key_t y; 204 for (i=0;i<16;i++){ 205 y[i] = btstack_crypto_cmac_x[i] ^ btstack_crypto_cmac_m_last[i]; 206 } 207 btstack_crypto_cmac_block_current++; 208 btstack_crypto_cmac_next_state(); 209 btstack_crypto_aes128_start(btstack_crypto_cmac_k, y); 210 break; 211 } 212 default: 213 log_info("btstack_crypto_cmac_handle_aes_engine_ready called in state %u", btstack_crypto_cmac_state); 214 break; 215 } 216 } 217 218 static void btstack_crypto_cmac_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 219 int i; 220 int carry = 0; 221 for (i=len-1; i >= 0 ; i--){ 222 int new_carry = data[i] >> 7; 223 data[i] = (data[i] << 1) | carry; 224 carry = new_carry; 225 } 226 } 227 228 static void btstack_crypto_cmac_handle_encryption_result(btstack_crypto_aes128_cmac_t * btstack_crypto_cmac, sm_key_t data){ 229 switch (btstack_crypto_cmac_state){ 230 case CMAC_W4_SUBKEYS: { 231 sm_key_t k1; 232 memcpy(k1, data, 16); 233 btstack_crypto_cmac_shift_left_by_one_bit_inplace(16, k1); 234 if (data[0] & 0x80){ 235 k1[15] ^= 0x87; 236 } 237 sm_key_t k2; 238 memcpy(k2, k1, 16); 239 btstack_crypto_cmac_shift_left_by_one_bit_inplace(16, k2); 240 if (k1[0] & 0x80){ 241 k2[15] ^= 0x87; 242 } 243 244 log_info_key("k", btstack_crypto_cmac_k); 245 log_info_key("k1", k1); 246 log_info_key("k2", k2); 247 248 // step 4: set m_last 249 int i; 250 if (btstack_crypto_cmac_last_block_complete(btstack_crypto_cmac)){ 251 for (i=0;i<16;i++){ 252 btstack_crypto_cmac_m_last[i] = btstack_crypto_cmac_get_byte(btstack_crypto_cmac, btstack_crypto_cmac->size - 16 + i) ^ k1[i]; 253 } 254 } else { 255 int valid_octets_in_last_block = btstack_crypto_cmac->size & 0x0f; 256 for (i=0;i<16;i++){ 257 if (i < valid_octets_in_last_block){ 258 btstack_crypto_cmac_m_last[i] = btstack_crypto_cmac_get_byte(btstack_crypto_cmac, (btstack_crypto_cmac->size & 0xfff0) + i) ^ k2[i]; 259 continue; 260 } 261 if (i == valid_octets_in_last_block){ 262 btstack_crypto_cmac_m_last[i] = 0x80 ^ k2[i]; 263 continue; 264 } 265 btstack_crypto_cmac_m_last[i] = k2[i]; 266 } 267 } 268 269 // next 270 btstack_crypto_cmac_state = (btstack_crypto_cmac_block_current < (btstack_crypto_cmac_block_count - 1)) ? CMAC_CALC_MI : CMAC_CALC_MLAST; 271 break; 272 } 273 case CMAC_W4_MI: 274 memcpy(btstack_crypto_cmac_x, data, 16); 275 btstack_crypto_cmac_state = (btstack_crypto_cmac_block_current < (btstack_crypto_cmac_block_count - 1)) ? CMAC_CALC_MI : CMAC_CALC_MLAST; 276 break; 277 case CMAC_W4_MLAST: 278 // done 279 log_info("Setting CMAC Engine to IDLE"); 280 btstack_crypto_cmac_state = CMAC_IDLE; 281 log_info_key("CMAC", data); 282 memcpy(btstack_crypto_cmac->hash, data, 16); 283 btstack_linked_list_pop(&btstack_crypto_operations); 284 (*btstack_crypto_cmac->btstack_crypto.context_callback.callback)(btstack_crypto_cmac->btstack_crypto.context_callback.context); 285 break; 286 default: 287 log_info("btstack_crypto_cmac_handle_encryption_result called in state %u", btstack_crypto_cmac_state); 288 break; 289 } 290 } 291 292 static void btstack_crypto_cmac_start(btstack_crypto_aes128_cmac_t * btstack_crypto_cmac){ 293 294 memcpy(btstack_crypto_cmac_k, btstack_crypto_cmac->key, 16); 295 memset(btstack_crypto_cmac_x, 0, 16); 296 btstack_crypto_cmac_block_current = 0; 297 298 // step 2: n := ceil(len/const_Bsize); 299 btstack_crypto_cmac_block_count = (btstack_crypto_cmac->size + 15) / 16; 300 301 // step 3: .. 302 if (btstack_crypto_cmac_block_count==0){ 303 btstack_crypto_cmac_block_count = 1; 304 } 305 log_info("btstack_crypto_cmac_start: len %u, block count %u", btstack_crypto_cmac->size, btstack_crypto_cmac_block_count); 306 307 // first, we need to compute l for k1, k2, and m_last 308 btstack_crypto_cmac_state = CMAC_CALC_SUBKEYS; 309 310 // let's go 311 btstack_crypto_cmac_handle_aes_engine_ready(btstack_crypto_cmac); 312 } 313 314 #ifndef USE_BTSTACK_AES128 315 316 /* 317 To encrypt the message data we use Counter (CTR) mode. We first 318 define the key stream blocks by: 319 320 S_i := E( K, A_i ) for i=0, 1, 2, ... 321 322 The values A_i are formatted as follows, where the Counter field i is 323 encoded in most-significant-byte first order: 324 325 Octet Number Contents 326 ------------ --------- 327 0 Flags 328 1 ... 15-L Nonce N 329 16-L ... 15 Counter i 330 331 Bit Number Contents 332 ---------- ---------------------- 333 7 Reserved (always zero) 334 6 Reserved (always zero) 335 5 ... 3 Zero 336 2 ... 0 L' 337 */ 338 339 static void btstack_crypto_ccm_setup_a_i(btstack_crypto_ccm_t * btstack_crypto_ccm, uint16_t counter){ 340 btstack_crypto_ccm_s[0] = 1; // L' = L - 1 341 memcpy(&btstack_crypto_ccm_s[1], btstack_crypto_ccm->nonce, 13); 342 big_endian_store_16(btstack_crypto_ccm_s, 14, counter); 343 #ifdef DEBUG_CCM 344 printf("ststack_crypto_ccm_setup_a_%u\n", counter); 345 printf("%16s: ", "ai"); 346 printf_hexdump(btstack_crypto_ccm_s, 16); 347 #endif 348 } 349 350 /* 351 The first step is to compute the authentication field T. This is 352 done using CBC-MAC [MAC]. We first define a sequence of blocks B_0, 353 B_1, ..., B_n and then apply CBC-MAC to these blocks. 354 355 The first block B_0 is formatted as follows, where l(m) is encoded in 356 most-significant-byte first order: 357 358 Octet Number Contents 359 ------------ --------- 360 0 Flags 361 1 ... 15-L Nonce N 362 16-L ... 15 l(m) 363 364 Within the first block B_0, the Flags field is formatted as follows: 365 366 Bit Number Contents 367 ---------- ---------------------- 368 7 Reserved (always zero) 369 6 Adata 370 5 ... 3 M' 371 2 ... 0 L' 372 */ 373 374 static void btstack_crypto_ccm_setup_b_0(btstack_crypto_ccm_t * btstack_crypto_ccm, uint8_t * b0){ 375 uint8_t m_prime = (btstack_crypto_ccm->auth_len - 2) / 2; 376 uint8_t Adata = btstack_crypto_ccm->aad_len ? 1 : 0; 377 b0[0] = (Adata << 6) | (m_prime << 3) | 1 ; // Adata, M', L' = L - 1 378 memcpy(&b0[1], btstack_crypto_ccm->nonce, 13); 379 big_endian_store_16(b0, 14, btstack_crypto_ccm->message_len); 380 #ifdef DEBUG_CCM 381 printf("%16s: ", "B0"); 382 printf_hexdump(b0, 16); 383 #endif 384 } 385 #endif 386 387 #ifdef ENABLE_ECC_P256 388 389 static void btstack_crypto_log_ec_publickey(const uint8_t * ec_q){ 390 log_info("Elliptic curve: X"); 391 log_info_hexdump(&ec_q[0],32); 392 log_info("Elliptic curve: Y"); 393 log_info_hexdump(&ec_q[32],32); 394 } 395 396 #if (defined(USE_MICRO_ECC_P256) && !defined(WICED_VERSION)) || defined(USE_MBEDTLS_ECC_P256) 397 // @return OK 398 static int sm_generate_f_rng(unsigned char * buffer, unsigned size){ 399 if (btstack_crypto_ecc_p256_key_generation_state != ECC_P256_KEY_GENERATION_ACTIVE) return 0; 400 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, btstack_crypto_ecc_p256_random_offset); 401 while (size) { 402 *buffer++ = btstack_crypto_ecc_p256_random[btstack_crypto_ecc_p256_random_offset++]; 403 size--; 404 } 405 return 1; 406 } 407 #endif 408 #ifdef USE_MBEDTLS_ECC_P256 409 // @return error - just wrap sm_generate_f_rng 410 static int sm_generate_f_rng_mbedtls(void * context, unsigned char * buffer, size_t size){ 411 UNUSED(context); 412 return sm_generate_f_rng(buffer, size) == 0; 413 } 414 #endif /* USE_MBEDTLS_ECC_P256 */ 415 416 static void btstack_crypto_ecc_p256_generate_key_software(void){ 417 418 btstack_crypto_ecc_p256_random_offset = 0; 419 420 // generate EC key 421 #ifdef USE_MICRO_ECC_P256 422 423 #ifndef WICED_VERSION 424 log_info("set uECC RNG for initial key generation with 64 random bytes"); 425 // micro-ecc from WICED SDK uses its wiced_crypto_get_random by default - no need to set it 426 uECC_set_rng(&sm_generate_f_rng); 427 #endif /* WICED_VERSION */ 428 429 #if uECC_SUPPORTS_secp256r1 430 // standard version 431 uECC_make_key(btstack_crypto_ecc_p256_public_key, btstack_crypto_ecc_p256_d, uECC_secp256r1()); 432 433 // disable RNG again, as returning no randmon data lets shared key generation fail 434 log_info("disable uECC RNG in standard version after key generation"); 435 uECC_set_rng(NULL); 436 #else 437 // static version 438 uECC_make_key(btstack_crypto_ecc_p256_public_key, btstack_crypto_ecc_p256_d); 439 #endif 440 #endif /* USE_MICRO_ECC_P256 */ 441 442 #ifdef USE_MBEDTLS_ECC_P256 443 mbedtls_mpi d; 444 mbedtls_ecp_point P; 445 mbedtls_mpi_init(&d); 446 mbedtls_ecp_point_init(&P); 447 int res = mbedtls_ecp_gen_keypair(&mbedtls_ec_group, &d, &P, &sm_generate_f_rng_mbedtls, NULL); 448 log_info("gen keypair %x", res); 449 mbedtls_mpi_write_binary(&P.X, &btstack_crypto_ecc_p256_public_key[0], 32); 450 mbedtls_mpi_write_binary(&P.Y, &btstack_crypto_ecc_p256_public_key[32], 32); 451 mbedtls_mpi_write_binary(&d, btstack_crypto_ecc_p256_d, 32); 452 mbedtls_ecp_point_free(&P); 453 mbedtls_mpi_free(&d); 454 #endif /* USE_MBEDTLS_ECC_P256 */ 455 } 456 457 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 458 static void btstack_crypto_ecc_p256_calculate_dhkey_software(btstack_crypto_ecc_p256_t * btstack_crypto_ec_p192){ 459 memset(btstack_crypto_ec_p192->dhkey, 0, 32); 460 461 #ifdef USE_MICRO_ECC_P256 462 #if uECC_SUPPORTS_secp256r1 463 // standard version 464 uECC_shared_secret(btstack_crypto_ec_p192->public_key, btstack_crypto_ecc_p256_d, btstack_crypto_ec_p192->dhkey, uECC_secp256r1()); 465 #else 466 // static version 467 uECC_shared_secret(btstack_crypto_ec_p192->public_key, btstack_crypto_ecc_p256_d, btstack_crypto_ec_p192->dhkey); 468 #endif 469 #endif 470 471 #ifdef USE_MBEDTLS_ECC_P256 472 // da * Pb 473 mbedtls_mpi d; 474 mbedtls_ecp_point Q; 475 mbedtls_ecp_point DH; 476 mbedtls_mpi_init(&d); 477 mbedtls_ecp_point_init(&Q); 478 mbedtls_ecp_point_init(&DH); 479 mbedtls_mpi_read_binary(&d, btstack_crypto_ecc_p256_d, 32); 480 mbedtls_mpi_read_binary(&Q.X, &btstack_crypto_ec_p192->public_key[0] , 32); 481 mbedtls_mpi_read_binary(&Q.Y, &btstack_crypto_ec_p192->public_key[32], 32); 482 mbedtls_mpi_lset(&Q.Z, 1); 483 mbedtls_ecp_mul(&mbedtls_ec_group, &DH, &d, &Q, NULL, NULL); 484 mbedtls_mpi_write_binary(&DH.X, btstack_crypto_ec_p192->dhkey, 32); 485 mbedtls_ecp_point_free(&DH); 486 mbedtls_mpi_free(&d); 487 mbedtls_ecp_point_free(&Q); 488 #endif 489 490 log_info("dhkey"); 491 log_info_hexdump(btstack_crypto_ec_p192->dhkey, 32); 492 } 493 #endif 494 495 #endif 496 497 #ifdef USE_BTSTACK_AES128 498 // CCM not implemented using software AES128 yet 499 #else 500 501 static void btstack_crypto_ccm_calc_s0(btstack_crypto_ccm_t * btstack_crypto_ccm){ 502 #ifdef DEBUG_CCM 503 printf("btstack_crypto_ccm_calc_s0\n"); 504 #endif 505 btstack_crypto_ccm->state = CCM_W4_S0; 506 btstack_crypto_ccm_setup_a_i(btstack_crypto_ccm, 0); 507 btstack_crypto_aes128_start(btstack_crypto_ccm->key, btstack_crypto_ccm_s); 508 } 509 510 static void btstack_crypto_ccm_calc_sn(btstack_crypto_ccm_t * btstack_crypto_ccm){ 511 #ifdef DEBUG_CCM 512 printf("btstack_crypto_ccm_calc_s%u\n", btstack_crypto_ccm->counter); 513 #endif 514 btstack_crypto_ccm->state = CCM_W4_SN; 515 btstack_crypto_ccm_setup_a_i(btstack_crypto_ccm, btstack_crypto_ccm->counter); 516 btstack_crypto_aes128_start(btstack_crypto_ccm->key, btstack_crypto_ccm_s); 517 } 518 519 static void btstack_crypto_ccm_calc_x1(btstack_crypto_ccm_t * btstack_crypto_ccm){ 520 uint8_t btstack_crypto_ccm_buffer[16]; 521 btstack_crypto_ccm->state = CCM_W4_X1; 522 btstack_crypto_ccm_setup_b_0(btstack_crypto_ccm, btstack_crypto_ccm_buffer); 523 btstack_crypto_aes128_start(btstack_crypto_ccm->key, btstack_crypto_ccm_buffer); 524 } 525 526 static void btstack_crypto_ccm_calc_xn(btstack_crypto_ccm_t * btstack_crypto_ccm, const uint8_t * plaintext){ 527 uint8_t btstack_crypto_ccm_buffer[16]; 528 btstack_crypto_ccm->state = CCM_W4_XN; 529 530 #ifdef DEBUG_CCM 531 printf("%16s: ", "bn"); 532 printf_hexdump(plaintext, 16); 533 #endif 534 uint8_t i; 535 uint8_t bytes_to_decrypt = btstack_crypto_ccm->block_len; 536 // use explicit min implementation as c-stat worried about out-of-bounds-reads 537 if (bytes_to_decrypt > 16) { 538 bytes_to_decrypt = 16; 539 } 540 for (i = 0; i < bytes_to_decrypt ; i++){ 541 btstack_crypto_ccm_buffer[i] = btstack_crypto_ccm->x_i[i] ^ plaintext[i]; 542 } 543 memcpy(&btstack_crypto_ccm_buffer[i], &btstack_crypto_ccm->x_i[i], 16 - bytes_to_decrypt); 544 #ifdef DEBUG_CCM 545 printf("%16s: ", "Xn XOR bn"); 546 printf_hexdump(btstack_crypto_ccm_buffer, 16); 547 #endif 548 549 btstack_crypto_aes128_start(btstack_crypto_ccm->key, btstack_crypto_ccm_buffer); 550 } 551 #endif 552 553 static void btstack_crypto_ccm_calc_aad_xn(btstack_crypto_ccm_t * btstack_crypto_ccm){ 554 // store length 555 if (btstack_crypto_ccm->aad_offset == 0){ 556 uint8_t len_buffer[2]; 557 big_endian_store_16(len_buffer, 0, btstack_crypto_ccm->aad_len); 558 btstack_crypto_ccm->x_i[0] ^= len_buffer[0]; 559 btstack_crypto_ccm->x_i[1] ^= len_buffer[1]; 560 btstack_crypto_ccm->aad_remainder_len += 2; 561 btstack_crypto_ccm->aad_offset += 2; 562 } 563 564 // fill from input 565 uint16_t bytes_free = 16 - btstack_crypto_ccm->aad_remainder_len; 566 uint16_t bytes_to_copy = btstack_min(bytes_free, btstack_crypto_ccm->block_len); 567 while (bytes_to_copy){ 568 btstack_crypto_ccm->x_i[btstack_crypto_ccm->aad_remainder_len++] ^= *btstack_crypto_ccm->input++; 569 btstack_crypto_ccm->aad_offset++; 570 btstack_crypto_ccm->block_len--; 571 bytes_to_copy--; 572 bytes_free--; 573 } 574 575 // if last block, fill with zeros 576 if (btstack_crypto_ccm->aad_offset == (btstack_crypto_ccm->aad_len + 2)){ 577 btstack_crypto_ccm->aad_remainder_len = 16; 578 } 579 // if not full, notify done 580 if (btstack_crypto_ccm->aad_remainder_len < 16){ 581 btstack_crypto_done(&btstack_crypto_ccm->btstack_crypto); 582 return; 583 } 584 585 // encrypt block 586 #ifdef DEBUG_CCM 587 printf("%16s: ", "Xn XOR Bn (aad)"); 588 printf_hexdump(btstack_crypto_ccm->x_i, 16); 589 #endif 590 591 btstack_crypto_ccm->aad_remainder_len = 0; 592 btstack_crypto_ccm->state = CCM_W4_AAD_XN; 593 btstack_crypto_aes128_start(btstack_crypto_ccm->key, btstack_crypto_ccm->x_i); 594 } 595 596 static void btstack_crypto_ccm_handle_s0(btstack_crypto_ccm_t * btstack_crypto_ccm, const uint8_t * data){ 597 // data is little-endian, flip on the fly 598 int i; 599 for (i=0;i<16;i++){ 600 btstack_crypto_ccm->x_i[i] = btstack_crypto_ccm->x_i[i] ^ data[15-i]; 601 } 602 btstack_crypto_done(&btstack_crypto_ccm->btstack_crypto); 603 } 604 605 static void btstack_crypto_ccm_handle_sn(btstack_crypto_ccm_t * btstack_crypto_ccm, const uint8_t * data){ 606 // data is little-endian, flip on the fly 607 int i; 608 uint16_t bytes_to_process = btstack_min(btstack_crypto_ccm->block_len, 16); 609 for (i=0;i<bytes_to_process;i++){ 610 btstack_crypto_ccm->output[i] = btstack_crypto_ccm->input[i] ^ data[15-i]; 611 } 612 } 613 614 static void btstack_crypto_ccm_next_block(btstack_crypto_ccm_t * btstack_crypto_ccm, btstack_crypto_ccm_state_t state_when_done){ 615 uint16_t bytes_to_process = btstack_min(btstack_crypto_ccm->block_len, 16); 616 // next block 617 btstack_crypto_ccm->counter++; 618 btstack_crypto_ccm->input += bytes_to_process; 619 btstack_crypto_ccm->output += bytes_to_process; 620 btstack_crypto_ccm->block_len -= bytes_to_process; 621 btstack_crypto_ccm->message_len -= bytes_to_process; 622 #ifdef DEBUG_CCM 623 printf("btstack_crypto_ccm_next_block (message len %u, block_len %u)\n", btstack_crypto_ccm->message_len, btstack_crypto_ccm->block_len); 624 #endif 625 if (btstack_crypto_ccm->message_len == 0){ 626 btstack_crypto_ccm->state = CCM_CALCULATE_S0; 627 } else { 628 btstack_crypto_ccm->state = state_when_done; 629 if (btstack_crypto_ccm->block_len == 0){ 630 btstack_crypto_done(&btstack_crypto_ccm->btstack_crypto); 631 } 632 } 633 } 634 635 static void btstack_crypto_run(void){ 636 637 btstack_crypto_aes128_t * btstack_crypto_aes128; 638 btstack_crypto_ccm_t * btstack_crypto_ccm; 639 btstack_crypto_aes128_cmac_t * btstack_crypto_cmac; 640 #ifdef ENABLE_ECC_P256 641 btstack_crypto_ecc_p256_t * btstack_crypto_ec_p192; 642 #endif 643 644 // stack up and running? 645 if (hci_get_state() != HCI_STATE_WORKING) return; 646 647 // try to do as much as possible 648 while (1){ 649 650 // anything to do? 651 if (btstack_linked_list_empty(&btstack_crypto_operations)) return; 652 653 // already active? 654 if (btstack_crypto_wait_for_hci_result) return; 655 656 // can send a command? 657 if (!hci_can_send_command_packet_now()) return; 658 659 // ok, find next task 660 btstack_crypto_t * btstack_crypto = (btstack_crypto_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 661 switch (btstack_crypto->operation){ 662 case BTSTACK_CRYPTO_RANDOM: 663 btstack_crypto_wait_for_hci_result = 1; 664 hci_send_cmd(&hci_le_rand); 665 break; 666 case BTSTACK_CRYPTO_AES128: 667 btstack_crypto_aes128 = (btstack_crypto_aes128_t *) btstack_crypto; 668 #ifdef USE_BTSTACK_AES128 669 btstack_aes128_calc(btstack_crypto_aes128->key, btstack_crypto_aes128->plaintext, btstack_crypto_aes128->ciphertext); 670 btstack_crypto_done(btstack_crypto); 671 #else 672 btstack_crypto_aes128_start(btstack_crypto_aes128->key, btstack_crypto_aes128->plaintext); 673 #endif 674 break; 675 case BTSTACK_CRYPTO_CMAC_MESSAGE: 676 case BTSTACK_CRYPTO_CMAC_GENERATOR: 677 btstack_crypto_wait_for_hci_result = 1; 678 btstack_crypto_cmac = (btstack_crypto_aes128_cmac_t *) btstack_crypto; 679 if (btstack_crypto_cmac_state == CMAC_IDLE){ 680 btstack_crypto_cmac_start(btstack_crypto_cmac); 681 } else { 682 btstack_crypto_cmac_handle_aes_engine_ready(btstack_crypto_cmac); 683 } 684 break; 685 686 case BTSTACK_CRYPTO_CCM_DIGEST_BLOCK: 687 case BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK: 688 case BTSTACK_CRYPTO_CCM_DECRYPT_BLOCK: 689 #ifdef USE_BTSTACK_AES128 690 UNUSED(btstack_crypto_ccm); 691 // NOTE: infinite output of this message 692 log_error("ccm not implemented for software aes128 yet"); 693 #else 694 btstack_crypto_ccm = (btstack_crypto_ccm_t *) btstack_crypto; 695 switch (btstack_crypto_ccm->state){ 696 case CCM_CALCULATE_AAD_XN: 697 btstack_crypto_ccm_calc_aad_xn(btstack_crypto_ccm); 698 break; 699 case CCM_CALCULATE_X1: 700 btstack_crypto_ccm_calc_x1(btstack_crypto_ccm); 701 break; 702 case CCM_CALCULATE_S0: 703 btstack_crypto_ccm_calc_s0(btstack_crypto_ccm); 704 break; 705 case CCM_CALCULATE_SN: 706 btstack_crypto_ccm_calc_sn(btstack_crypto_ccm); 707 break; 708 case CCM_CALCULATE_XN: 709 btstack_crypto_ccm_calc_xn(btstack_crypto_ccm, btstack_crypto->operation == BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK ? btstack_crypto_ccm->input : btstack_crypto_ccm->output); 710 break; 711 default: 712 break; 713 } 714 #endif 715 break; 716 717 #ifdef ENABLE_ECC_P256 718 case BTSTACK_CRYPTO_ECC_P256_GENERATE_KEY: 719 btstack_crypto_ec_p192 = (btstack_crypto_ecc_p256_t *) btstack_crypto; 720 switch (btstack_crypto_ecc_p256_key_generation_state){ 721 case ECC_P256_KEY_GENERATION_DONE: 722 // done 723 btstack_crypto_log_ec_publickey(btstack_crypto_ecc_p256_public_key); 724 memcpy(btstack_crypto_ec_p192->public_key, btstack_crypto_ecc_p256_public_key, 64); 725 btstack_linked_list_pop(&btstack_crypto_operations); 726 (*btstack_crypto_ec_p192->btstack_crypto.context_callback.callback)(btstack_crypto_ec_p192->btstack_crypto.context_callback.context); 727 break; 728 case ECC_P256_KEY_GENERATION_IDLE: 729 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 730 log_info("start ecc random"); 731 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_GENERATING_RANDOM; 732 btstack_crypto_ecc_p256_random_offset = 0; 733 btstack_crypto_wait_for_hci_result = 1; 734 hci_send_cmd(&hci_le_rand); 735 #else 736 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_W4_KEY; 737 btstack_crypto_wait_for_hci_result = 1; 738 hci_send_cmd(&hci_le_read_local_p256_public_key); 739 #endif 740 break; 741 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 742 case ECC_P256_KEY_GENERATION_GENERATING_RANDOM: 743 log_info("more ecc random"); 744 btstack_crypto_wait_for_hci_result = 1; 745 hci_send_cmd(&hci_le_rand); 746 break; 747 #endif 748 default: 749 break; 750 } 751 break; 752 case BTSTACK_CRYPTO_ECC_P256_CALCULATE_DHKEY: 753 btstack_crypto_ec_p192 = (btstack_crypto_ecc_p256_t *) btstack_crypto; 754 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 755 btstack_crypto_ecc_p256_calculate_dhkey_software(btstack_crypto_ec_p192); 756 // done 757 btstack_linked_list_pop(&btstack_crypto_operations); 758 (*btstack_crypto_ec_p192->btstack_crypto.context_callback.callback)(btstack_crypto_ec_p192->btstack_crypto.context_callback.context); 759 #else 760 btstack_crypto_wait_for_hci_result = 1; 761 hci_send_cmd(&hci_le_generate_dhkey, &btstack_crypto_ec_p192->public_key[0], &btstack_crypto_ec_p192->public_key[32]); 762 #endif 763 break; 764 765 #endif /* ENABLE_ECC_P256 */ 766 767 default: 768 break; 769 } 770 } 771 } 772 773 static void btstack_crypto_handle_random_data(const uint8_t * data, uint16_t len){ 774 btstack_crypto_random_t * btstack_crypto_random; 775 btstack_crypto_t * btstack_crypto = (btstack_crypto_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 776 uint16_t bytes_to_copy; 777 if (!btstack_crypto) return; 778 switch (btstack_crypto->operation){ 779 case BTSTACK_CRYPTO_RANDOM: 780 btstack_crypto_random = (btstack_crypto_random_t*) btstack_crypto; 781 bytes_to_copy = btstack_min(btstack_crypto_random->size, len); 782 memcpy(btstack_crypto_random->buffer, data, bytes_to_copy); 783 btstack_crypto_random->buffer += bytes_to_copy; 784 btstack_crypto_random->size -= bytes_to_copy; 785 // data processed, more? 786 if (!btstack_crypto_random->size) { 787 // done 788 btstack_linked_list_pop(&btstack_crypto_operations); 789 (*btstack_crypto_random->btstack_crypto.context_callback.callback)(btstack_crypto_random->btstack_crypto.context_callback.context); 790 } 791 break; 792 #ifdef ENABLE_ECC_P256 793 case BTSTACK_CRYPTO_ECC_P256_GENERATE_KEY: 794 memcpy(&btstack_crypto_ecc_p256_random[btstack_crypto_ecc_p256_random_len], data, 8); 795 btstack_crypto_ecc_p256_random_len += 8; 796 if (btstack_crypto_ecc_p256_random_len >= 64) { 797 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_ACTIVE; 798 btstack_crypto_ecc_p256_generate_key_software(); 799 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_DONE; 800 } 801 break; 802 #endif 803 default: 804 break; 805 } 806 // more work? 807 btstack_crypto_run(); 808 } 809 810 static void btstack_crypto_handle_encryption_result(const uint8_t * data){ 811 btstack_crypto_aes128_t * btstack_crypto_aes128; 812 btstack_crypto_aes128_cmac_t * btstack_crypto_cmac; 813 btstack_crypto_ccm_t * btstack_crypto_ccm; 814 uint8_t result[16]; 815 816 btstack_crypto_t * btstack_crypto = (btstack_crypto_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 817 if (!btstack_crypto) return; 818 switch (btstack_crypto->operation){ 819 case BTSTACK_CRYPTO_AES128: 820 btstack_crypto_aes128 = (btstack_crypto_aes128_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 821 reverse_128(data, btstack_crypto_aes128->ciphertext); 822 btstack_crypto_done(btstack_crypto); 823 break; 824 case BTSTACK_CRYPTO_CMAC_GENERATOR: 825 case BTSTACK_CRYPTO_CMAC_MESSAGE: 826 btstack_crypto_cmac = (btstack_crypto_aes128_cmac_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 827 reverse_128(data, result); 828 btstack_crypto_cmac_handle_encryption_result(btstack_crypto_cmac, result); 829 break; 830 case BTSTACK_CRYPTO_CCM_DIGEST_BLOCK: 831 btstack_crypto_ccm = (btstack_crypto_ccm_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 832 switch (btstack_crypto_ccm->state){ 833 case CCM_W4_X1: 834 reverse_128(data, btstack_crypto_ccm->x_i); 835 #ifdef DEBUG_CCM 836 printf("%16s: ", "X1"); 837 printf_hexdump(btstack_crypto_ccm->x_i, 16); 838 #endif 839 btstack_crypto_ccm->aad_remainder_len = 0; 840 btstack_crypto_ccm->state = CCM_CALCULATE_AAD_XN; 841 break; 842 case CCM_W4_AAD_XN: 843 reverse_128(data, btstack_crypto_ccm->x_i); 844 #ifdef DEBUG_CCM 845 printf("%16s: ", "Xn+1 AAD"); 846 printf_hexdump(btstack_crypto_ccm->x_i, 16); 847 #endif 848 // more aad? 849 if (btstack_crypto_ccm->aad_offset < (btstack_crypto_ccm->aad_len + 2)){ 850 btstack_crypto_ccm->state = CCM_CALCULATE_AAD_XN; 851 } else { 852 // done 853 btstack_crypto_done(btstack_crypto); 854 } 855 break; 856 default: 857 break; 858 } 859 break; 860 case BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK: 861 btstack_crypto_ccm = (btstack_crypto_ccm_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 862 switch (btstack_crypto_ccm->state){ 863 case CCM_W4_X1: 864 reverse_128(data, btstack_crypto_ccm->x_i); 865 #ifdef DEBUG_CCM 866 printf("%16s: ", "X1"); 867 printf_hexdump(btstack_crypto_ccm->x_i, 16); 868 #endif 869 btstack_crypto_ccm->state = CCM_CALCULATE_XN; 870 break; 871 case CCM_W4_XN: 872 reverse_128(data, btstack_crypto_ccm->x_i); 873 #ifdef DEBUG_CCM 874 printf("%16s: ", "Xn+1"); 875 printf_hexdump(btstack_crypto_ccm->x_i, 16); 876 #endif 877 btstack_crypto_ccm->state = CCM_CALCULATE_SN; 878 break; 879 case CCM_W4_S0: 880 #ifdef DEBUG_CCM 881 reverse_128(data, result); 882 printf("%16s: ", "X0"); 883 printf_hexdump(btstack_crypto_ccm->x_i, 16); 884 #endif 885 btstack_crypto_ccm_handle_s0(btstack_crypto_ccm, data); 886 break; 887 case CCM_W4_SN: 888 #ifdef DEBUG_CCM 889 reverse_128(data, result); 890 printf("%16s: ", "Sn"); 891 printf_hexdump(btstack_crypto_ccm->x_i, 16); 892 #endif 893 btstack_crypto_ccm_handle_sn(btstack_crypto_ccm, data); 894 btstack_crypto_ccm_next_block(btstack_crypto_ccm, CCM_CALCULATE_XN); 895 break; 896 default: 897 break; 898 } 899 break; 900 case BTSTACK_CRYPTO_CCM_DECRYPT_BLOCK: 901 btstack_crypto_ccm = (btstack_crypto_ccm_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 902 switch (btstack_crypto_ccm->state){ 903 case CCM_W4_X1: 904 reverse_128(data, btstack_crypto_ccm->x_i); 905 #ifdef DEBUG_CCM 906 printf("%16s: ", "X1"); 907 printf_hexdump(btstack_crypto_ccm->x_i, 16); 908 #endif 909 btstack_crypto_ccm->state = CCM_CALCULATE_SN; 910 break; 911 case CCM_W4_XN: 912 reverse_128(data, btstack_crypto_ccm->x_i); 913 #ifdef DEBUG_CCM 914 printf("%16s: ", "Xn+1"); 915 printf_hexdump(btstack_crypto_ccm->x_i, 16); 916 #endif 917 btstack_crypto_ccm_next_block(btstack_crypto_ccm, CCM_CALCULATE_SN); 918 break; 919 case CCM_W4_S0: 920 btstack_crypto_ccm_handle_s0(btstack_crypto_ccm, data); 921 break; 922 case CCM_W4_SN: 923 btstack_crypto_ccm_handle_sn(btstack_crypto_ccm, data); 924 btstack_crypto_ccm->state = CCM_CALCULATE_XN; 925 break; 926 default: 927 break; 928 } 929 break; 930 default: 931 break; 932 } 933 } 934 935 static void btstack_crypto_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 936 UNUSED(cid); // ok: there is no channel 937 UNUSED(size); // ok: fixed format events read from HCI buffer 938 939 #ifdef ENABLE_ECC_P256 940 #ifndef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 941 btstack_crypto_ecc_p256_t * btstack_crypto_ec_p192; 942 #endif 943 #endif 944 945 if (packet_type != HCI_EVENT_PACKET) return; 946 947 switch (hci_event_packet_get_type(packet)){ 948 case BTSTACK_EVENT_STATE: 949 log_info("BTSTACK_EVENT_STATE"); 950 if (btstack_event_state_get_state(packet) != HCI_STATE_HALTING) break; 951 if (!btstack_crypto_wait_for_hci_result) break; 952 // request stack to defer shutdown a bit 953 hci_halting_defer(); 954 break; 955 956 case HCI_EVENT_COMMAND_COMPLETE: 957 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 958 if (!btstack_crypto_wait_for_hci_result) return; 959 btstack_crypto_wait_for_hci_result = 0; 960 btstack_crypto_handle_encryption_result(&packet[6]); 961 } 962 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 963 if (!btstack_crypto_wait_for_hci_result) return; 964 btstack_crypto_wait_for_hci_result = 0; 965 btstack_crypto_handle_random_data(&packet[6], 8); 966 } 967 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_local_supported_commands)){ 968 int ecdh_operations_supported = (packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+34] & 0x06) == 0x06; 969 log_info("controller supports ECDH operation: %u", ecdh_operations_supported); 970 #ifdef ENABLE_ECC_P256 971 #ifndef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 972 if (!ecdh_operations_supported){ 973 // mbedTLS can also be used if already available (and malloc is supported) 974 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"); 975 } 976 #endif 977 #endif 978 } 979 break; 980 981 #ifdef ENABLE_ECC_P256 982 #ifndef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 983 case HCI_EVENT_LE_META: 984 btstack_crypto_ec_p192 = (btstack_crypto_ecc_p256_t*) btstack_linked_list_get_first_item(&btstack_crypto_operations); 985 if (!btstack_crypto_ec_p192) break; 986 switch (hci_event_le_meta_get_subevent_code(packet)){ 987 case HCI_SUBEVENT_LE_READ_LOCAL_P256_PUBLIC_KEY_COMPLETE: 988 if (btstack_crypto_ec_p192->btstack_crypto.operation != BTSTACK_CRYPTO_ECC_P256_GENERATE_KEY) break; 989 if (!btstack_crypto_wait_for_hci_result) return; 990 btstack_crypto_wait_for_hci_result = 0; 991 if (hci_subevent_le_read_local_p256_public_key_complete_get_status(packet)){ 992 log_error("Read Local P256 Public Key failed"); 993 } 994 hci_subevent_le_read_local_p256_public_key_complete_get_dhkey_x(packet, &btstack_crypto_ecc_p256_public_key[0]); 995 hci_subevent_le_read_local_p256_public_key_complete_get_dhkey_y(packet, &btstack_crypto_ecc_p256_public_key[32]); 996 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_DONE; 997 break; 998 case HCI_SUBEVENT_LE_GENERATE_DHKEY_COMPLETE: 999 if (btstack_crypto_ec_p192->btstack_crypto.operation != BTSTACK_CRYPTO_ECC_P256_CALCULATE_DHKEY) break; 1000 if (!btstack_crypto_wait_for_hci_result) return; 1001 btstack_crypto_wait_for_hci_result = 0; 1002 if (hci_subevent_le_generate_dhkey_complete_get_status(packet)){ 1003 log_error("Generate DHKEY failed -> abort"); 1004 } 1005 hci_subevent_le_generate_dhkey_complete_get_dhkey(packet, btstack_crypto_ec_p192->dhkey); 1006 // done 1007 btstack_linked_list_pop(&btstack_crypto_operations); 1008 (*btstack_crypto_ec_p192->btstack_crypto.context_callback.callback)(btstack_crypto_ec_p192->btstack_crypto.context_callback.context); 1009 break; 1010 default: 1011 break; 1012 } 1013 break; 1014 #endif 1015 #endif 1016 default: 1017 break; 1018 } 1019 1020 // try processing 1021 btstack_crypto_run(); 1022 } 1023 1024 void btstack_crypto_init(void){ 1025 if (btstack_crypto_initialized) return; 1026 btstack_crypto_initialized = 1; 1027 1028 // register with HCI 1029 hci_event_callback_registration.callback = &btstack_crypto_event_handler; 1030 hci_add_event_handler(&hci_event_callback_registration); 1031 1032 #ifdef USE_MBEDTLS_ECC_P256 1033 mbedtls_ecp_group_init(&mbedtls_ec_group); 1034 mbedtls_ecp_group_load(&mbedtls_ec_group, MBEDTLS_ECP_DP_SECP256R1); 1035 #endif 1036 } 1037 1038 void btstack_crypto_random_generate(btstack_crypto_random_t * request, uint8_t * buffer, uint16_t size, void (* callback)(void * arg), void * callback_arg){ 1039 request->btstack_crypto.context_callback.callback = callback; 1040 request->btstack_crypto.context_callback.context = callback_arg; 1041 request->btstack_crypto.operation = BTSTACK_CRYPTO_RANDOM; 1042 request->buffer = buffer; 1043 request->size = size; 1044 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1045 btstack_crypto_run(); 1046 } 1047 1048 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){ 1049 request->btstack_crypto.context_callback.callback = callback; 1050 request->btstack_crypto.context_callback.context = callback_arg; 1051 request->btstack_crypto.operation = BTSTACK_CRYPTO_AES128; 1052 request->key = key; 1053 request->plaintext = plaintext; 1054 request->ciphertext = ciphertext; 1055 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1056 btstack_crypto_run(); 1057 } 1058 1059 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){ 1060 request->btstack_crypto.context_callback.callback = callback; 1061 request->btstack_crypto.context_callback.context = callback_arg; 1062 request->btstack_crypto.operation = BTSTACK_CRYPTO_CMAC_GENERATOR; 1063 request->key = key; 1064 request->size = size; 1065 request->data.get_byte_callback = get_byte_callback; 1066 request->hash = hash; 1067 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1068 btstack_crypto_run(); 1069 } 1070 1071 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){ 1072 request->btstack_crypto.context_callback.callback = callback; 1073 request->btstack_crypto.context_callback.context = callback_arg; 1074 request->btstack_crypto.operation = BTSTACK_CRYPTO_CMAC_MESSAGE; 1075 request->key = key; 1076 request->size = size; 1077 request->data.message = message; 1078 request->hash = hash; 1079 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1080 btstack_crypto_run(); 1081 } 1082 1083 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){ 1084 request->btstack_crypto.context_callback.callback = callback; 1085 request->btstack_crypto.context_callback.context = callback_arg; 1086 request->btstack_crypto.operation = BTSTACK_CRYPTO_CMAC_MESSAGE; 1087 request->key = zero; 1088 request->size = len; 1089 request->data.message = message; 1090 request->hash = hash; 1091 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1092 btstack_crypto_run(); 1093 } 1094 1095 #ifdef ENABLE_ECC_P256 1096 void btstack_crypto_ecc_p256_generate_key(btstack_crypto_ecc_p256_t * request, uint8_t * public_key, void (* callback)(void * arg), void * callback_arg){ 1097 // reset key generation 1098 if (btstack_crypto_ecc_p256_key_generation_state == ECC_P256_KEY_GENERATION_DONE){ 1099 btstack_crypto_ecc_p256_random_len = 0; 1100 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_IDLE; 1101 } 1102 request->btstack_crypto.context_callback.callback = callback; 1103 request->btstack_crypto.context_callback.context = callback_arg; 1104 request->btstack_crypto.operation = BTSTACK_CRYPTO_ECC_P256_GENERATE_KEY; 1105 request->public_key = public_key; 1106 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1107 btstack_crypto_run(); 1108 } 1109 1110 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){ 1111 request->btstack_crypto.context_callback.callback = callback; 1112 request->btstack_crypto.context_callback.context = callback_arg; 1113 request->btstack_crypto.operation = BTSTACK_CRYPTO_ECC_P256_CALCULATE_DHKEY; 1114 request->public_key = (uint8_t *) public_key; 1115 request->dhkey = dhkey; 1116 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1117 btstack_crypto_run(); 1118 } 1119 1120 int btstack_crypto_ecc_p256_validate_public_key(const uint8_t * public_key){ 1121 1122 // validate public key using micro-ecc 1123 int err = 0; 1124 1125 #ifdef USE_MICRO_ECC_P256 1126 #if uECC_SUPPORTS_secp256r1 1127 // standard version 1128 err = uECC_valid_public_key(public_key, uECC_secp256r1()) == 0; 1129 #else 1130 // static version 1131 err = uECC_valid_public_key(public_key) == 0; 1132 #endif 1133 #endif 1134 1135 #ifdef USE_MBEDTLS_ECC_P256 1136 mbedtls_ecp_point Q; 1137 mbedtls_ecp_point_init( &Q ); 1138 mbedtls_mpi_read_binary(&Q.X, &public_key[0], 32); 1139 mbedtls_mpi_read_binary(&Q.Y, &public_key[32], 32); 1140 mbedtls_mpi_lset(&Q.Z, 1); 1141 err = mbedtls_ecp_check_pubkey(&mbedtls_ec_group, &Q); 1142 mbedtls_ecp_point_free( & Q); 1143 #endif 1144 1145 if (err){ 1146 log_error("public key invalid %x", err); 1147 } 1148 return err; 1149 } 1150 #endif 1151 1152 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){ 1153 request->key = key; 1154 request->nonce = nonce; 1155 request->message_len = message_len; 1156 request->aad_len = additional_authenticated_data_len; 1157 request->aad_offset = 0; 1158 request->auth_len = auth_len; 1159 request->counter = 1; 1160 request->state = CCM_CALCULATE_X1; 1161 } 1162 1163 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){ 1164 // not implemented yet 1165 request->btstack_crypto.context_callback.callback = callback; 1166 request->btstack_crypto.context_callback.context = callback_arg; 1167 request->btstack_crypto.operation = BTSTACK_CRYPTO_CCM_DIGEST_BLOCK; 1168 request->block_len = additional_authenticated_data_len; 1169 request->input = additional_authenticated_data; 1170 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1171 btstack_crypto_run(); 1172 } 1173 1174 void btstack_crypto_ccm_get_authentication_value(btstack_crypto_ccm_t * request, uint8_t * authentication_value){ 1175 memcpy(authentication_value, request->x_i, request->auth_len); 1176 } 1177 1178 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){ 1179 #ifdef DEBUG_CCM 1180 printf("\nbtstack_crypto_ccm_encrypt_block, len %u\n", block_len); 1181 #endif 1182 request->btstack_crypto.context_callback.callback = callback; 1183 request->btstack_crypto.context_callback.context = callback_arg; 1184 request->btstack_crypto.operation = BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK; 1185 request->block_len = block_len; 1186 request->input = plaintext; 1187 request->output = ciphertext; 1188 if (request->state != CCM_CALCULATE_X1){ 1189 request->state = CCM_CALCULATE_XN; 1190 } 1191 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1192 btstack_crypto_run(); 1193 } 1194 1195 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){ 1196 request->btstack_crypto.context_callback.callback = callback; 1197 request->btstack_crypto.context_callback.context = callback_arg; 1198 request->btstack_crypto.operation = BTSTACK_CRYPTO_CCM_DECRYPT_BLOCK; 1199 request->block_len = block_len; 1200 request->input = ciphertext; 1201 request->output = plaintext; 1202 if (request->state != CCM_CALCULATE_X1){ 1203 request->state = CCM_CALCULATE_SN; 1204 } 1205 btstack_linked_list_add_tail(&btstack_crypto_operations, (btstack_linked_item_t*) request); 1206 btstack_crypto_run(); 1207 } 1208 1209 // PTS only 1210 void btstack_crypto_ecc_p256_set_key(const uint8_t * public_key, const uint8_t * private_key){ 1211 #ifdef USE_SOFTWARE_ECC_P256_IMPLEMENTATION 1212 memcpy(btstack_crypto_ecc_p256_d, private_key, 32); 1213 memcpy(btstack_crypto_ecc_p256_public_key, public_key, 64); 1214 btstack_crypto_ecc_p256_key_generation_state = ECC_P256_KEY_GENERATION_DONE; 1215 #else 1216 UNUSED(public_key); 1217 UNUSED(private_key); 1218 #endif 1219 } 1220 // Unit testing 1221 int btstack_crypto_idle(void){ 1222 return btstack_linked_list_empty(&btstack_crypto_operations); 1223 } 1224 void btstack_crypto_reset(void){ 1225 btstack_crypto_operations = NULL; 1226 btstack_crypto_wait_for_hci_result = 0; 1227 } 1228