1 /* 2 * Copyright (c) 2013, Google Inc. 3 * 4 * SPDX-License-Identifier: GPL-2.0+ 5 */ 6 7 #ifndef USE_HOSTCC 8 #include <common.h> 9 #include <crypto.h> 10 #include <fdtdec.h> 11 #include <misc.h> 12 #include <asm/types.h> 13 #include <asm/byteorder.h> 14 #include <linux/errno.h> 15 #include <asm/types.h> 16 #include <asm/unaligned.h> 17 #include <dm.h> 18 #else 19 #include "fdt_host.h" 20 #include "mkimage.h" 21 #include <fdt_support.h> 22 #endif 23 #include <u-boot/rsa-mod-exp.h> 24 #include <u-boot/rsa.h> 25 26 /* Default public exponent for backward compatibility */ 27 #define RSA_DEFAULT_PUBEXP 65537 28 29 /** 30 * rsa_verify_padding() - Verify RSA message padding is valid 31 * 32 * Verify a RSA message's padding is consistent with PKCS1.5 33 * padding as described in the RSA PKCS#1 v2.1 standard. 34 * 35 * @msg: Padded message 36 * @pad_len: Number of expected padding bytes 37 * @algo: Checksum algo structure having information on DER encoding etc. 38 * @return 0 on success, != 0 on failure 39 */ 40 static int rsa_verify_padding(const uint8_t *msg, const int pad_len, 41 struct checksum_algo *algo) 42 { 43 int ff_len; 44 int ret; 45 46 /* first byte must be 0x00 */ 47 ret = *msg++; 48 /* second byte must be 0x01 */ 49 ret |= *msg++ ^ 0x01; 50 /* next ff_len bytes must be 0xff */ 51 ff_len = pad_len - algo->der_len - 3; 52 ret |= *msg ^ 0xff; 53 ret |= memcmp(msg, msg+1, ff_len-1); 54 msg += ff_len; 55 /* next byte must be 0x00 */ 56 ret |= *msg++; 57 /* next der_len bytes must match der_prefix */ 58 ret |= memcmp(msg, algo->der_prefix, algo->der_len); 59 60 return ret; 61 } 62 63 #if !defined(USE_HOSTCC) 64 #if CONFIG_IS_ENABLED(FIT_HW_CRYPTO) 65 static void rsa_convert_big_endian(uint32_t *dst, const uint32_t *src, 66 int total_len, int convert_len) 67 { 68 int total_wd, convert_wd, i; 69 70 if (total_len < convert_len) 71 convert_len = total_len; 72 73 total_wd = total_len / sizeof(uint32_t); 74 convert_wd = convert_len / sizeof(uint32_t); 75 for (i = 0; i < convert_wd; i++) 76 dst[i] = fdt32_to_cpu(src[total_wd - 1 - i]); 77 } 78 79 static int rsa_mod_exp_hw(struct key_prop *prop, const uint8_t *sig, 80 const uint32_t sig_len, const uint32_t key_len, 81 uint8_t *output) 82 { 83 struct udevice *dev; 84 uint8_t sig_reverse[sig_len]; 85 uint8_t buf[sig_len]; 86 rsa_key rsa_key; 87 int i, ret; 88 89 if (key_len != RSA2048_BYTES) 90 return -EINVAL; 91 92 rsa_key.algo = CRYPTO_RSA2048; 93 rsa_key.n = malloc(key_len); 94 rsa_key.e = malloc(key_len); 95 rsa_key.c = malloc(key_len); 96 if (!rsa_key.n || !rsa_key.e || !rsa_key.c) 97 return -ENOMEM; 98 99 rsa_convert_big_endian(rsa_key.n, (uint32_t *)prop->modulus, 100 key_len, key_len); 101 rsa_convert_big_endian(rsa_key.e, (uint32_t *)prop->public_exponent_BN, 102 key_len, key_len); 103 #ifdef CONFIG_ROCKCHIP_CRYPTO_V1 104 rsa_convert_big_endian(rsa_key.c, (uint32_t *)prop->factor_c, 105 key_len, key_len); 106 #else 107 rsa_convert_big_endian(rsa_key.c, (uint32_t *)prop->factor_np, 108 key_len, key_len); 109 #endif 110 for (i = 0; i < sig_len; i++) 111 sig_reverse[sig_len-1-i] = sig[i]; 112 113 dev = crypto_get_device(rsa_key.algo); 114 if (!dev) { 115 printf("No crypto device for expected RSA\n"); 116 return -ENODEV; 117 } 118 119 ret = crypto_rsa_verify(dev, &rsa_key, (u8 *)sig_reverse, buf); 120 if (ret) 121 goto out; 122 123 for (i = 0; i < sig_len; i++) 124 sig_reverse[sig_len-1-i] = buf[i]; 125 126 memcpy(output, sig_reverse, sig_len); 127 out: 128 free(rsa_key.n); 129 free(rsa_key.e); 130 free(rsa_key.c); 131 132 return ret; 133 } 134 #endif 135 #endif 136 137 int padding_pkcs_15_verify(struct image_sign_info *info, 138 uint8_t *msg, int msg_len, 139 const uint8_t *hash, int hash_len) 140 { 141 struct checksum_algo *checksum = info->checksum; 142 int ret, pad_len = msg_len - checksum->checksum_len; 143 144 /* Check pkcs1.5 padding bytes. */ 145 ret = rsa_verify_padding(msg, pad_len, checksum); 146 if (ret) { 147 debug("In RSAVerify(): Padding check failed!\n"); 148 return -EINVAL; 149 } 150 151 /* Check hash. */ 152 if (memcmp((uint8_t *)msg + pad_len, hash, msg_len - pad_len)) { 153 debug("In RSAVerify(): Hash check failed!\n"); 154 return -EACCES; 155 } 156 157 return 0; 158 } 159 160 #ifdef CONFIG_FIT_ENABLE_RSASSA_PSS_SUPPORT 161 static void u32_i2osp(uint32_t val, uint8_t *buf) 162 { 163 buf[0] = (uint8_t)((val >> 24) & 0xff); 164 buf[1] = (uint8_t)((val >> 16) & 0xff); 165 buf[2] = (uint8_t)((val >> 8) & 0xff); 166 buf[3] = (uint8_t)((val >> 0) & 0xff); 167 } 168 169 /** 170 * mask_generation_function1() - generate an octet string 171 * 172 * Generate an octet string used to check rsa signature. 173 * It use an input octet string and a hash function. 174 * 175 * @checksum: A Hash function 176 * @seed: Specifies an input variable octet string 177 * @seed_len: Size of the input octet string 178 * @output: Specifies the output octet string 179 * @output_len: Size of the output octet string 180 * @return 0 if the octet string was correctly generated, others on error 181 */ 182 static int mask_generation_function1(struct checksum_algo *checksum, 183 uint8_t *seed, int seed_len, 184 uint8_t *output, int output_len) 185 { 186 struct image_region region[2]; 187 int ret = 0, i, i_output = 0, region_count = 2; 188 uint32_t counter = 0; 189 uint8_t buf_counter[4], *tmp; 190 int hash_len = checksum->checksum_len; 191 192 memset(output, 0, output_len); 193 194 region[0].data = seed; 195 region[0].size = seed_len; 196 region[1].data = &buf_counter[0]; 197 region[1].size = 4; 198 199 tmp = malloc(hash_len); 200 if (!tmp) { 201 debug("%s: can't allocate array tmp\n", __func__); 202 ret = -ENOMEM; 203 goto out; 204 } 205 206 while (i_output < output_len) { 207 u32_i2osp(counter, &buf_counter[0]); 208 209 ret = checksum->calculate(checksum->name, 210 region, region_count, 211 tmp); 212 if (ret < 0) { 213 debug("%s: Error in checksum calculation\n", __func__); 214 goto out; 215 } 216 217 i = 0; 218 while ((i_output < output_len) && (i < hash_len)) { 219 output[i_output] = tmp[i]; 220 i_output++; 221 i++; 222 } 223 224 counter++; 225 } 226 227 out: 228 free(tmp); 229 230 return ret; 231 } 232 233 static int compute_hash_prime(struct checksum_algo *checksum, 234 uint8_t *pad, int pad_len, 235 uint8_t *hash, int hash_len, 236 uint8_t *salt, int salt_len, 237 uint8_t *hprime) 238 { 239 struct image_region region[3]; 240 int ret, region_count = 3; 241 242 region[0].data = pad; 243 region[0].size = pad_len; 244 region[1].data = hash; 245 region[1].size = hash_len; 246 region[2].data = salt; 247 region[2].size = salt_len; 248 249 ret = checksum->calculate(checksum->name, region, region_count, hprime); 250 if (ret < 0) { 251 debug("%s: Error in checksum calculation\n", __func__); 252 goto out; 253 } 254 255 out: 256 return ret; 257 } 258 259 int padding_pss_verify(struct image_sign_info *info, 260 uint8_t *msg, int msg_len, 261 const uint8_t *hash, int hash_len) 262 { 263 uint8_t *masked_db = NULL; 264 int masked_db_len = msg_len - hash_len - 1; 265 uint8_t *h = NULL, *hprime = NULL; 266 int h_len = hash_len; 267 uint8_t *db_mask = NULL; 268 int db_mask_len = masked_db_len; 269 uint8_t *db = NULL, *salt = NULL; 270 int db_len = masked_db_len, salt_len = msg_len - hash_len - 2; 271 uint8_t pad_zero[8] = { 0 }; 272 int ret, i, leftmost_bits = 1; 273 uint8_t leftmost_mask; 274 struct checksum_algo *checksum = info->checksum; 275 276 /* first, allocate everything */ 277 masked_db = malloc(masked_db_len); 278 h = malloc(h_len); 279 db_mask = malloc(db_mask_len); 280 db = malloc(db_len); 281 salt = malloc(salt_len); 282 hprime = malloc(hash_len); 283 if (!masked_db || !h || !db_mask || !db || !salt || !hprime) { 284 printf("%s: can't allocate some buffer\n", __func__); 285 ret = -ENOMEM; 286 goto out; 287 } 288 289 /* step 4: check if the last byte is 0xbc */ 290 if (msg[msg_len - 1] != 0xbc) { 291 printf("%s: invalid pss padding (0xbc is missing)\n", __func__); 292 ret = -EINVAL; 293 goto out; 294 } 295 296 /* step 5 */ 297 memcpy(masked_db, msg, masked_db_len); 298 memcpy(h, msg + masked_db_len, h_len); 299 300 /* step 6 */ 301 leftmost_mask = (0xff >> (8 - leftmost_bits)) << (8 - leftmost_bits); 302 if (masked_db[0] & leftmost_mask) { 303 printf("%s: invalid pss padding ", __func__); 304 printf("(leftmost bit of maskedDB not zero)\n"); 305 ret = -EINVAL; 306 goto out; 307 } 308 309 /* step 7 */ 310 mask_generation_function1(checksum, h, h_len, db_mask, db_mask_len); 311 312 /* step 8 */ 313 for (i = 0; i < db_len; i++) 314 db[i] = masked_db[i] ^ db_mask[i]; 315 316 /* step 9 */ 317 db[0] &= 0xff >> leftmost_bits; 318 319 /* step 10 */ 320 if (db[0] != 0x01) { 321 printf("%s: invalid pss padding ", __func__); 322 printf("(leftmost byte of db isn't 0x01)\n"); 323 ret = EINVAL; 324 goto out; 325 } 326 327 /* step 11 */ 328 memcpy(salt, &db[1], salt_len); 329 330 /* step 12 & 13 */ 331 compute_hash_prime(checksum, pad_zero, 8, 332 (uint8_t *)hash, hash_len, 333 salt, salt_len, hprime); 334 335 /* step 14 */ 336 ret = memcmp(h, hprime, hash_len); 337 338 out: 339 free(hprime); 340 free(salt); 341 free(db); 342 free(db_mask); 343 free(h); 344 free(masked_db); 345 346 return ret; 347 } 348 #endif 349 350 /** 351 * rsa_verify_key() - Verify a signature against some data using RSA Key 352 * 353 * Verify a RSA PKCS1.5 signature against an expected hash using 354 * the RSA Key properties in prop structure. 355 * 356 * @info: Specifies key and FIT information 357 * @prop: Specifies key 358 * @sig: Signature 359 * @sig_len: Number of bytes in signature 360 * @hash: Pointer to the expected hash 361 * @key_len: Number of bytes in rsa key 362 * @return 0 if verified, -ve on error 363 */ 364 static int rsa_verify_key(struct image_sign_info *info, 365 struct key_prop *prop, const uint8_t *sig, 366 const uint32_t sig_len, const uint8_t *hash, 367 const uint32_t key_len) 368 { 369 int ret; 370 struct checksum_algo *checksum = info->checksum; 371 struct padding_algo *padding = info->padding; 372 int hash_len = checksum->checksum_len; 373 374 if (!prop || !sig || !hash || !checksum) 375 return -EIO; 376 377 if (sig_len != (prop->num_bits / 8)) { 378 debug("Signature is of incorrect length %d\n", sig_len); 379 return -EINVAL; 380 } 381 382 debug("Checksum algorithm: %s", checksum->name); 383 384 /* Sanity check for stack size */ 385 if (sig_len > RSA_MAX_SIG_BITS / 8) { 386 debug("Signature length %u exceeds maximum %d\n", sig_len, 387 RSA_MAX_SIG_BITS / 8); 388 return -EINVAL; 389 } 390 391 uint8_t buf[sig_len]; 392 393 #if !defined(USE_HOSTCC) 394 #if CONFIG_IS_ENABLED(FIT_HW_CRYPTO) 395 ret = rsa_mod_exp_hw(prop, sig, sig_len, key_len, buf); 396 #else 397 struct udevice *mod_exp_dev; 398 399 ret = uclass_get_device(UCLASS_MOD_EXP, 0, &mod_exp_dev); 400 if (ret) { 401 printf("RSA: Can't find Modular Exp implementation\n"); 402 return -EINVAL; 403 } 404 405 ret = rsa_mod_exp(mod_exp_dev, sig, sig_len, prop, buf); 406 #endif 407 #else 408 ret = rsa_mod_exp_sw(sig, sig_len, prop, buf); 409 #endif 410 if (ret) { 411 debug("Error in Modular exponentation\n"); 412 return ret; 413 } 414 415 ret = padding->verify(info, buf, key_len, hash, hash_len); 416 if (ret) { 417 debug("In RSAVerify(): padding check failed!\n"); 418 return ret; 419 } 420 421 return 0; 422 } 423 424 static int rsa_get_key_prop(struct key_prop *prop, struct image_sign_info *info, int node) 425 { 426 const void *blob = info->fdt_blob; 427 int length; 428 int hash_node; 429 430 if (node < 0) { 431 debug("%s: Skipping invalid node", __func__); 432 return -EBADF; 433 } 434 435 if (!prop) { 436 debug("%s: The prop is NULL", __func__); 437 return -EBADF; 438 } 439 440 prop->burn_key = fdtdec_get_int(blob, node, "burn-key-hash", 0); 441 442 prop->num_bits = fdtdec_get_int(blob, node, "rsa,num-bits", 0); 443 444 prop->n0inv = fdtdec_get_int(blob, node, "rsa,n0-inverse", 0); 445 446 prop->public_exponent = fdt_getprop(blob, node, "rsa,exponent", &length); 447 if (!prop->public_exponent || length < sizeof(uint64_t)) 448 prop->public_exponent = NULL; 449 450 prop->exp_len = sizeof(uint64_t); 451 prop->modulus = fdt_getprop(blob, node, "rsa,modulus", NULL); 452 prop->public_exponent_BN = fdt_getprop(blob, node, "rsa,exponent-BN", NULL); 453 prop->rr = fdt_getprop(blob, node, "rsa,r-squared", NULL); 454 #ifdef CONFIG_ROCKCHIP_CRYPTO_V1 455 hash_node = fdt_subnode_offset(blob, node, "hash@c"); 456 #else 457 hash_node = fdt_subnode_offset(blob, node, "hash@np"); 458 #endif 459 if (hash_node >= 0) 460 prop->hash = fdt_getprop(blob, hash_node, "value", NULL); 461 462 if (!prop->num_bits || !prop->modulus) { 463 debug("%s: Missing RSA key info", __func__); 464 return -EFAULT; 465 } 466 467 #ifdef CONFIG_ROCKCHIP_CRYPTO_V1 468 prop->factor_c = fdt_getprop(blob, node, "rsa,c", NULL); 469 if (!prop.factor_c) 470 return -EFAULT; 471 #else 472 prop->factor_np = fdt_getprop(blob, node, "rsa,np", NULL); 473 if (!prop->factor_np) 474 return -EFAULT; 475 #endif 476 477 return 0; 478 } 479 480 /** 481 * rsa_verify_with_keynode() - Verify a signature against some data using 482 * information in node with prperties of RSA Key like modulus, exponent etc. 483 * 484 * Parse sign-node and fill a key_prop structure with properties of the 485 * key. Verify a RSA PKCS1.5 signature against an expected hash using 486 * the properties parsed 487 * 488 * @info: Specifies key and FIT information 489 * @hash: Pointer to the expected hash 490 * @sig: Signature 491 * @sig_len: Number of bytes in signature 492 * @node: Node having the RSA Key properties 493 * @return 0 if verified, -ve on error 494 */ 495 static int rsa_verify_with_keynode(struct image_sign_info *info, 496 const void *hash, uint8_t *sig, 497 uint sig_len, int node) 498 { 499 struct key_prop prop; 500 501 if (rsa_get_key_prop(&prop, info, node)) 502 return -EFAULT; 503 504 return rsa_verify_key(info, &prop, sig, sig_len, hash, 505 info->crypto->key_len); 506 } 507 508 int rsa_verify(struct image_sign_info *info, 509 const struct image_region region[], int region_count, 510 uint8_t *sig, uint sig_len) 511 { 512 const void *blob = info->fdt_blob; 513 /* Reserve memory for maximum checksum-length */ 514 uint8_t hash[info->crypto->key_len]; 515 int ndepth, noffset; 516 int sig_node, node; 517 char name[100]; 518 int ret; 519 520 /* 521 * Verify that the checksum-length does not exceed the 522 * rsa-signature-length 523 */ 524 if (info->checksum->checksum_len > 525 info->crypto->key_len) { 526 debug("%s: invlaid checksum-algorithm %s for %s\n", 527 __func__, info->checksum->name, info->crypto->name); 528 return -EINVAL; 529 } 530 531 sig_node = fdt_subnode_offset(blob, 0, FIT_SIG_NODENAME); 532 if (sig_node < 0) { 533 debug("%s: No signature node found\n", __func__); 534 return -ENOENT; 535 } 536 537 /* Calculate checksum with checksum-algorithm */ 538 ret = info->checksum->calculate(info->checksum->name, 539 region, region_count, hash); 540 if (ret < 0) { 541 debug("%s: Error in checksum calculation\n", __func__); 542 return -EINVAL; 543 } 544 545 /* See if we must use a particular key */ 546 if (info->required_keynode != -1) { 547 ret = rsa_verify_with_keynode(info, hash, sig, sig_len, 548 info->required_keynode); 549 if (!ret) 550 return ret; 551 } 552 553 /* Look for a key that matches our hint */ 554 snprintf(name, sizeof(name), "key-%s", info->keyname); 555 node = fdt_subnode_offset(blob, sig_node, name); 556 ret = rsa_verify_with_keynode(info, hash, sig, sig_len, node); 557 if (!ret) 558 return ret; 559 560 /* No luck, so try each of the keys in turn */ 561 for (ndepth = 0, noffset = fdt_next_node(info->fit, sig_node, &ndepth); 562 (noffset >= 0) && (ndepth > 0); 563 noffset = fdt_next_node(info->fit, noffset, &ndepth)) { 564 if (ndepth == 1 && noffset != node) { 565 ret = rsa_verify_with_keynode(info, hash, sig, sig_len, 566 noffset); 567 if (!ret) 568 break; 569 } 570 } 571 572 return ret; 573 } 574 575 #if !defined(USE_HOSTCC) 576 #ifdef CONFIG_SPL_FIT_HW_CRYPTO 577 int rsa_burn_key_hash(struct image_sign_info *info) 578 { 579 char *rsa_key; 580 void *n, *e, *c; 581 uint32_t key_len; 582 struct udevice *dev; 583 struct key_prop prop; 584 char name[100] = {0}; 585 u16 secure_boot_enable = 0; 586 const void *blob = info->fdt_blob; 587 uint8_t digest[FIT_MAX_HASH_LEN]; 588 uint8_t digest_read[FIT_MAX_HASH_LEN]; 589 int sig_node, node, digest_len, i, ret = 0; 590 591 dev = misc_otp_get_device(OTP_S); 592 if (!dev) 593 return -ENODEV; 594 595 ret = misc_otp_read(dev, OTP_SECURE_BOOT_ENABLE_ADDR, 596 &secure_boot_enable, OTP_SECURE_BOOT_ENABLE_SIZE); 597 if (ret) 598 return ret; 599 600 if (secure_boot_enable) 601 return 0; 602 603 sig_node = fdt_subnode_offset(blob, 0, FIT_SIG_NODENAME); 604 if (sig_node < 0) { 605 debug("%s: No signature node found\n", __func__); 606 return -ENOENT; 607 } 608 609 snprintf(name, sizeof(name), "key-%s", info->keyname); 610 node = fdt_subnode_offset(blob, sig_node, name); 611 612 if (rsa_get_key_prop(&prop, info, node)) 613 return -1; 614 615 if (!(prop.burn_key)) 616 return -EPERM; 617 618 if (!prop.hash || !prop.modulus || !prop.public_exponent_BN) 619 return -ENOENT; 620 #ifdef CONFIG_ROCKCHIP_CRYPTO_V1 621 if (!prop.factor_c) 622 return -ENOENT; 623 #else 624 if (!prop.factor_np) 625 return -ENOENT; 626 #endif 627 key_len = info->crypto->key_len; 628 if (info->crypto->key_len != RSA2048_BYTES) 629 return -EINVAL; 630 631 rsa_key = calloc(key_len * 3, sizeof(char)); 632 if (!rsa_key) 633 return -ENOMEM; 634 635 n = rsa_key; 636 e = rsa_key + CONFIG_RSA_N_SIZE; 637 c = rsa_key + CONFIG_RSA_N_SIZE + CONFIG_RSA_E_SIZE; 638 rsa_convert_big_endian(n, (uint32_t *)prop.modulus, 639 key_len, CONFIG_RSA_N_SIZE); 640 rsa_convert_big_endian(e, (uint32_t *)prop.public_exponent_BN, 641 key_len, CONFIG_RSA_E_SIZE); 642 #ifdef CONFIG_ROCKCHIP_CRYPTO_V1 643 rsa_convert_big_endian(c, (uint32_t *)prop.factor_c, 644 key_len, CONFIG_RSA_C_SIZE); 645 #else 646 rsa_convert_big_endian(c, (uint32_t *)prop.factor_np, 647 key_len, CONFIG_RSA_C_SIZE); 648 #endif 649 650 ret = calculate_hash(rsa_key, CONFIG_RSA_N_SIZE + CONFIG_RSA_E_SIZE + CONFIG_RSA_C_SIZE, 651 info->checksum->name, digest, &digest_len); 652 if (ret) 653 goto error; 654 655 if (memcmp(digest, prop.hash, digest_len) != 0) { 656 printf("RSA: Compare public key hash fail.\n"); 657 goto error; 658 } 659 660 /* burn key hash here */ 661 ret = misc_otp_read(dev, OTP_RSA_HASH_ADDR, digest_read, OTP_RSA_HASH_SIZE); 662 if (ret) 663 goto error; 664 665 for (i = 0; i < OTP_RSA_HASH_SIZE; i++) { 666 if (digest_read[i]) { 667 printf("RSA: The secure region has been written.\n"); 668 ret = -EIO; 669 goto error; 670 } 671 } 672 673 ret = misc_otp_write(dev, OTP_RSA_HASH_ADDR, digest, OTP_RSA_HASH_SIZE); 674 if (ret) 675 goto error; 676 677 memset(digest_read, 0, FIT_MAX_HASH_LEN); 678 ret = misc_otp_read(dev, OTP_RSA_HASH_ADDR, digest_read, OTP_RSA_HASH_SIZE); 679 if (ret) 680 goto error; 681 682 if (memcmp(digest, digest_read, digest_len) != 0) { 683 printf("RSA: Write public key hash fail.\n"); 684 goto error; 685 } 686 687 secure_boot_enable = 0xff; 688 ret = misc_otp_write(dev, OTP_SECURE_BOOT_ENABLE_ADDR, 689 &secure_boot_enable, OTP_SECURE_BOOT_ENABLE_SIZE); 690 if (ret) 691 goto error; 692 693 printf("RSA: Write key hash successfully\n"); 694 695 error: 696 free(rsa_key); 697 698 return ret; 699 } 700 #endif 701 #endif 702