1/* 2 * The RSA public-key cryptosystem 3 * 4 * Copyright The Mbed TLS Contributors 5 * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later 6 */ 7 8/* 9 * The following sources were referenced in the design of this implementation 10 * of the RSA algorithm: 11 * 12 * [1] A method for obtaining digital signatures and public-key cryptosystems 13 * R Rivest, A Shamir, and L Adleman 14 * http://people.csail.mit.edu/rivest/pubs.html#RSA78 15 * 16 * [2] Handbook of Applied Cryptography - 1997, Chapter 8 17 * Menezes, van Oorschot and Vanstone 18 * 19 * [3] Malware Guard Extension: Using SGX to Conceal Cache Attacks 20 * Michael Schwarz, Samuel Weiser, Daniel Gruss, Clémentine Maurice and 21 * Stefan Mangard 22 * https://arxiv.org/abs/1702.08719v2 23 * 24 */ 25 26#include "common.h" 27 28#if defined(MBEDTLS_RSA_C) 29 30#include "mbedtls/rsa.h" 31#include "bignum_core.h" 32#include "rsa_alt_helpers.h" 33#include "rsa_internal.h" 34#include "mbedtls/oid.h" 35#include "mbedtls/asn1write.h" 36#include "mbedtls/platform_util.h" 37#include "mbedtls/error.h" 38#include "constant_time_internal.h" 39#include "mbedtls/constant_time.h" 40#include "md_psa.h" 41 42#include <string.h> 43 44#if defined(MBEDTLS_PKCS1_V15) && !defined(__OpenBSD__) && !defined(__NetBSD__) 45#include <stdlib.h> 46#endif 47 48#include "mbedtls/platform.h" 49 50/* 51 * Wrapper around mbedtls_asn1_get_mpi() that rejects zero. 52 * 53 * The value zero is: 54 * - never a valid value for an RSA parameter 55 * - interpreted as "omitted, please reconstruct" by mbedtls_rsa_complete(). 56 * 57 * Since values can't be omitted in PKCS#1, passing a zero value to 58 * rsa_complete() would be incorrect, so reject zero values early. 59 */ 60static int asn1_get_nonzero_mpi(unsigned char **p, 61 const unsigned char *end, 62 mbedtls_mpi *X) 63{ 64 int ret; 65 66 ret = mbedtls_asn1_get_mpi(p, end, X); 67 if (ret != 0) { 68 return ret; 69 } 70 71 if (mbedtls_mpi_cmp_int(X, 0) == 0) { 72 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 73 } 74 75 return 0; 76} 77 78int mbedtls_rsa_parse_key(mbedtls_rsa_context *rsa, const unsigned char *key, size_t keylen) 79{ 80 int ret, version; 81 size_t len; 82 unsigned char *p, *end; 83 84 mbedtls_mpi T; 85 mbedtls_mpi_init(&T); 86 87 p = (unsigned char *) key; 88 end = p + keylen; 89 90 /* 91 * This function parses the RSAPrivateKey (PKCS#1) 92 * 93 * RSAPrivateKey ::= SEQUENCE { 94 * version Version, 95 * modulus INTEGER, -- n 96 * publicExponent INTEGER, -- e 97 * privateExponent INTEGER, -- d 98 * prime1 INTEGER, -- p 99 * prime2 INTEGER, -- q 100 * exponent1 INTEGER, -- d mod (p-1) 101 * exponent2 INTEGER, -- d mod (q-1) 102 * coefficient INTEGER, -- (inverse of q) mod p 103 * otherPrimeInfos OtherPrimeInfos OPTIONAL 104 * } 105 */ 106 if ((ret = mbedtls_asn1_get_tag(&p, end, &len, 107 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) { 108 return ret; 109 } 110 111 if (end != p + len) { 112 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 113 } 114 115 if ((ret = mbedtls_asn1_get_int(&p, end, &version)) != 0) { 116 return ret; 117 } 118 119 if (version != 0) { 120 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 121 } 122 123 /* Import N */ 124 if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || 125 (ret = mbedtls_rsa_import(rsa, &T, NULL, NULL, 126 NULL, NULL)) != 0) { 127 goto cleanup; 128 } 129 130 /* Import E */ 131 if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || 132 (ret = mbedtls_rsa_import(rsa, NULL, NULL, NULL, 133 NULL, &T)) != 0) { 134 goto cleanup; 135 } 136 137 /* Import D */ 138 if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || 139 (ret = mbedtls_rsa_import(rsa, NULL, NULL, NULL, 140 &T, NULL)) != 0) { 141 goto cleanup; 142 } 143 144 /* Import P */ 145 if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || 146 (ret = mbedtls_rsa_import(rsa, NULL, &T, NULL, 147 NULL, NULL)) != 0) { 148 goto cleanup; 149 } 150 151 /* Import Q */ 152 if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || 153 (ret = mbedtls_rsa_import(rsa, NULL, NULL, &T, 154 NULL, NULL)) != 0) { 155 goto cleanup; 156 } 157 158#if !defined(MBEDTLS_RSA_NO_CRT) && !defined(MBEDTLS_RSA_ALT) 159 /* 160 * The RSA CRT parameters DP, DQ and QP are nominally redundant, in 161 * that they can be easily recomputed from D, P and Q. However by 162 * parsing them from the PKCS1 structure it is possible to avoid 163 * recalculating them which both reduces the overhead of loading 164 * RSA private keys into memory and also avoids side channels which 165 * can arise when computing those values, since all of D, P, and Q 166 * are secret. See https://eprint.iacr.org/2020/055 for a 167 * description of one such attack. 168 */ 169 170 /* Import DP */ 171 if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || 172 (ret = mbedtls_mpi_copy(&rsa->DP, &T)) != 0) { 173 goto cleanup; 174 } 175 176 /* Import DQ */ 177 if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || 178 (ret = mbedtls_mpi_copy(&rsa->DQ, &T)) != 0) { 179 goto cleanup; 180 } 181 182 /* Import QP */ 183 if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || 184 (ret = mbedtls_mpi_copy(&rsa->QP, &T)) != 0) { 185 goto cleanup; 186 } 187 188#else 189 /* Verify existence of the CRT params */ 190 if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || 191 (ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || 192 (ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0) { 193 goto cleanup; 194 } 195#endif 196 197 /* rsa_complete() doesn't complete anything with the default 198 * implementation but is still called: 199 * - for the benefit of alternative implementation that may want to 200 * pre-compute stuff beyond what's provided (eg Montgomery factors) 201 * - as is also sanity-checks the key 202 * 203 * Furthermore, we also check the public part for consistency with 204 * mbedtls_pk_parse_pubkey(), as it includes size minima for example. 205 */ 206 if ((ret = mbedtls_rsa_complete(rsa)) != 0 || 207 (ret = mbedtls_rsa_check_pubkey(rsa)) != 0) { 208 goto cleanup; 209 } 210 211 if (p != end) { 212 ret = MBEDTLS_ERR_ASN1_LENGTH_MISMATCH; 213 } 214 215cleanup: 216 217 mbedtls_mpi_free(&T); 218 219 if (ret != 0) { 220 mbedtls_rsa_free(rsa); 221 } 222 223 return ret; 224} 225 226int mbedtls_rsa_parse_pubkey(mbedtls_rsa_context *rsa, const unsigned char *key, size_t keylen) 227{ 228 unsigned char *p = (unsigned char *) key; 229 unsigned char *end = (unsigned char *) (key + keylen); 230 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 231 size_t len; 232 233 /* 234 * RSAPublicKey ::= SEQUENCE { 235 * modulus INTEGER, -- n 236 * publicExponent INTEGER -- e 237 * } 238 */ 239 240 if ((ret = mbedtls_asn1_get_tag(&p, end, &len, 241 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) { 242 return ret; 243 } 244 245 if (end != p + len) { 246 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 247 } 248 249 /* Import N */ 250 if ((ret = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_INTEGER)) != 0) { 251 return ret; 252 } 253 254 if ((ret = mbedtls_rsa_import_raw(rsa, p, len, NULL, 0, NULL, 0, 255 NULL, 0, NULL, 0)) != 0) { 256 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 257 } 258 259 p += len; 260 261 /* Import E */ 262 if ((ret = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_INTEGER)) != 0) { 263 return ret; 264 } 265 266 if ((ret = mbedtls_rsa_import_raw(rsa, NULL, 0, NULL, 0, NULL, 0, 267 NULL, 0, p, len)) != 0) { 268 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 269 } 270 271 p += len; 272 273 if (mbedtls_rsa_complete(rsa) != 0 || 274 mbedtls_rsa_check_pubkey(rsa) != 0) { 275 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 276 } 277 278 if (p != end) { 279 return MBEDTLS_ERR_ASN1_LENGTH_MISMATCH; 280 } 281 282 return 0; 283} 284 285int mbedtls_rsa_write_key(const mbedtls_rsa_context *rsa, unsigned char *start, 286 unsigned char **p) 287{ 288 size_t len = 0; 289 int ret; 290 291 mbedtls_mpi T; /* Temporary holding the exported parameters */ 292 293 /* 294 * Export the parameters one after another to avoid simultaneous copies. 295 */ 296 297 mbedtls_mpi_init(&T); 298 299 /* Export QP */ 300 if ((ret = mbedtls_rsa_export_crt(rsa, NULL, NULL, &T)) != 0 || 301 (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { 302 goto end_of_export; 303 } 304 len += ret; 305 306 /* Export DQ */ 307 if ((ret = mbedtls_rsa_export_crt(rsa, NULL, &T, NULL)) != 0 || 308 (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { 309 goto end_of_export; 310 } 311 len += ret; 312 313 /* Export DP */ 314 if ((ret = mbedtls_rsa_export_crt(rsa, &T, NULL, NULL)) != 0 || 315 (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { 316 goto end_of_export; 317 } 318 len += ret; 319 320 /* Export Q */ 321 if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, &T, NULL, NULL)) != 0 || 322 (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { 323 goto end_of_export; 324 } 325 len += ret; 326 327 /* Export P */ 328 if ((ret = mbedtls_rsa_export(rsa, NULL, &T, NULL, NULL, NULL)) != 0 || 329 (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { 330 goto end_of_export; 331 } 332 len += ret; 333 334 /* Export D */ 335 if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, &T, NULL)) != 0 || 336 (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { 337 goto end_of_export; 338 } 339 len += ret; 340 341 /* Export E */ 342 if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, NULL, &T)) != 0 || 343 (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { 344 goto end_of_export; 345 } 346 len += ret; 347 348 /* Export N */ 349 if ((ret = mbedtls_rsa_export(rsa, &T, NULL, NULL, NULL, NULL)) != 0 || 350 (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { 351 goto end_of_export; 352 } 353 len += ret; 354 355end_of_export: 356 357 mbedtls_mpi_free(&T); 358 if (ret < 0) { 359 return ret; 360 } 361 362 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_int(p, start, 0)); 363 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len)); 364 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, 365 MBEDTLS_ASN1_CONSTRUCTED | 366 MBEDTLS_ASN1_SEQUENCE)); 367 368 return (int) len; 369} 370 371/* 372 * RSAPublicKey ::= SEQUENCE { 373 * modulus INTEGER, -- n 374 * publicExponent INTEGER -- e 375 * } 376 */ 377int mbedtls_rsa_write_pubkey(const mbedtls_rsa_context *rsa, unsigned char *start, 378 unsigned char **p) 379{ 380 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 381 size_t len = 0; 382 mbedtls_mpi T; 383 384 mbedtls_mpi_init(&T); 385 386 /* Export E */ 387 if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, NULL, &T)) != 0 || 388 (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { 389 goto end_of_export; 390 } 391 len += ret; 392 393 /* Export N */ 394 if ((ret = mbedtls_rsa_export(rsa, &T, NULL, NULL, NULL, NULL)) != 0 || 395 (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { 396 goto end_of_export; 397 } 398 len += ret; 399 400end_of_export: 401 402 mbedtls_mpi_free(&T); 403 if (ret < 0) { 404 return ret; 405 } 406 407 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len)); 408 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_CONSTRUCTED | 409 MBEDTLS_ASN1_SEQUENCE)); 410 411 return (int) len; 412} 413 414#if defined(MBEDTLS_PKCS1_V15) && defined(MBEDTLS_RSA_C) && !defined(MBEDTLS_RSA_ALT) 415 416/** This function performs the unpadding part of a PKCS#1 v1.5 decryption 417 * operation (EME-PKCS1-v1_5 decoding). 418 * 419 * \note The return value from this function is a sensitive value 420 * (this is unusual). #MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE shouldn't happen 421 * in a well-written application, but 0 vs #MBEDTLS_ERR_RSA_INVALID_PADDING 422 * is often a situation that an attacker can provoke and leaking which 423 * one is the result is precisely the information the attacker wants. 424 * 425 * \param input The input buffer which is the payload inside PKCS#1v1.5 426 * encryption padding, called the "encoded message EM" 427 * by the terminology. 428 * \param ilen The length of the payload in the \p input buffer. 429 * \param output The buffer for the payload, called "message M" by the 430 * PKCS#1 terminology. This must be a writable buffer of 431 * length \p output_max_len bytes. 432 * \param olen The address at which to store the length of 433 * the payload. This must not be \c NULL. 434 * \param output_max_len The length in bytes of the output buffer \p output. 435 * 436 * \return \c 0 on success. 437 * \return #MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE 438 * The output buffer is too small for the unpadded payload. 439 * \return #MBEDTLS_ERR_RSA_INVALID_PADDING 440 * The input doesn't contain properly formatted padding. 441 */ 442static int mbedtls_ct_rsaes_pkcs1_v15_unpadding(unsigned char *input, 443 size_t ilen, 444 unsigned char *output, 445 size_t output_max_len, 446 size_t *olen) 447{ 448 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 449 size_t i, plaintext_max_size; 450 451 /* The following variables take sensitive values: their value must 452 * not leak into the observable behavior of the function other than 453 * the designated outputs (output, olen, return value). Otherwise 454 * this would open the execution of the function to 455 * side-channel-based variants of the Bleichenbacher padding oracle 456 * attack. Potential side channels include overall timing, memory 457 * access patterns (especially visible to an adversary who has access 458 * to a shared memory cache), and branches (especially visible to 459 * an adversary who has access to a shared code cache or to a shared 460 * branch predictor). */ 461 size_t pad_count = 0; 462 mbedtls_ct_condition_t bad; 463 mbedtls_ct_condition_t pad_done; 464 size_t plaintext_size = 0; 465 mbedtls_ct_condition_t output_too_large; 466 467 plaintext_max_size = (output_max_len > ilen - 11) ? ilen - 11 468 : output_max_len; 469 470 /* Check and get padding length in constant time and constant 471 * memory trace. The first byte must be 0. */ 472 bad = mbedtls_ct_bool(input[0]); 473 474 475 /* Decode EME-PKCS1-v1_5 padding: 0x00 || 0x02 || PS || 0x00 476 * where PS must be at least 8 nonzero bytes. */ 477 bad = mbedtls_ct_bool_or(bad, mbedtls_ct_uint_ne(input[1], MBEDTLS_RSA_CRYPT)); 478 479 /* Read the whole buffer. Set pad_done to nonzero if we find 480 * the 0x00 byte and remember the padding length in pad_count. */ 481 pad_done = MBEDTLS_CT_FALSE; 482 for (i = 2; i < ilen; i++) { 483 mbedtls_ct_condition_t found = mbedtls_ct_uint_eq(input[i], 0); 484 pad_done = mbedtls_ct_bool_or(pad_done, found); 485 pad_count += mbedtls_ct_uint_if_else_0(mbedtls_ct_bool_not(pad_done), 1); 486 } 487 488 /* If pad_done is still zero, there's no data, only unfinished padding. */ 489 bad = mbedtls_ct_bool_or(bad, mbedtls_ct_bool_not(pad_done)); 490 491 /* There must be at least 8 bytes of padding. */ 492 bad = mbedtls_ct_bool_or(bad, mbedtls_ct_uint_gt(8, pad_count)); 493 494 /* If the padding is valid, set plaintext_size to the number of 495 * remaining bytes after stripping the padding. If the padding 496 * is invalid, avoid leaking this fact through the size of the 497 * output: use the maximum message size that fits in the output 498 * buffer. Do it without branches to avoid leaking the padding 499 * validity through timing. RSA keys are small enough that all the 500 * size_t values involved fit in unsigned int. */ 501 plaintext_size = mbedtls_ct_uint_if( 502 bad, (unsigned) plaintext_max_size, 503 (unsigned) (ilen - pad_count - 3)); 504 505 /* Set output_too_large to 0 if the plaintext fits in the output 506 * buffer and to 1 otherwise. */ 507 output_too_large = mbedtls_ct_uint_gt(plaintext_size, 508 plaintext_max_size); 509 510 /* Set ret without branches to avoid timing attacks. Return: 511 * - INVALID_PADDING if the padding is bad (bad != 0). 512 * - OUTPUT_TOO_LARGE if the padding is good but the decrypted 513 * plaintext does not fit in the output buffer. 514 * - 0 if the padding is correct. */ 515 ret = mbedtls_ct_error_if( 516 bad, 517 MBEDTLS_ERR_RSA_INVALID_PADDING, 518 mbedtls_ct_error_if_else_0(output_too_large, MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE) 519 ); 520 521 /* If the padding is bad or the plaintext is too large, zero the 522 * data that we're about to copy to the output buffer. 523 * We need to copy the same amount of data 524 * from the same buffer whether the padding is good or not to 525 * avoid leaking the padding validity through overall timing or 526 * through memory or cache access patterns. */ 527 mbedtls_ct_zeroize_if(mbedtls_ct_bool_or(bad, output_too_large), input + 11, ilen - 11); 528 529 /* If the plaintext is too large, truncate it to the buffer size. 530 * Copy anyway to avoid revealing the length through timing, because 531 * revealing the length is as bad as revealing the padding validity 532 * for a Bleichenbacher attack. */ 533 plaintext_size = mbedtls_ct_uint_if(output_too_large, 534 (unsigned) plaintext_max_size, 535 (unsigned) plaintext_size); 536 537 /* Move the plaintext to the leftmost position where it can start in 538 * the working buffer, i.e. make it start plaintext_max_size from 539 * the end of the buffer. Do this with a memory access trace that 540 * does not depend on the plaintext size. After this move, the 541 * starting location of the plaintext is no longer sensitive 542 * information. */ 543 mbedtls_ct_memmove_left(input + ilen - plaintext_max_size, 544 plaintext_max_size, 545 plaintext_max_size - plaintext_size); 546 547 /* Finally copy the decrypted plaintext plus trailing zeros into the output 548 * buffer. If output_max_len is 0, then output may be an invalid pointer 549 * and the result of memcpy() would be undefined; prevent undefined 550 * behavior making sure to depend only on output_max_len (the size of the 551 * user-provided output buffer), which is independent from plaintext 552 * length, validity of padding, success of the decryption, and other 553 * secrets. */ 554 if (output_max_len != 0) { 555 memcpy(output, input + ilen - plaintext_max_size, plaintext_max_size); 556 } 557 558 /* Report the amount of data we copied to the output buffer. In case 559 * of errors (bad padding or output too large), the value of *olen 560 * when this function returns is not specified. Making it equivalent 561 * to the good case limits the risks of leaking the padding validity. */ 562 *olen = plaintext_size; 563 564 return ret; 565} 566 567#endif /* MBEDTLS_PKCS1_V15 && MBEDTLS_RSA_C && ! MBEDTLS_RSA_ALT */ 568 569#if !defined(MBEDTLS_RSA_ALT) 570 571int mbedtls_rsa_import(mbedtls_rsa_context *ctx, 572 const mbedtls_mpi *N, 573 const mbedtls_mpi *P, const mbedtls_mpi *Q, 574 const mbedtls_mpi *D, const mbedtls_mpi *E) 575{ 576 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 577 578 if ((N != NULL && (ret = mbedtls_mpi_copy(&ctx->N, N)) != 0) || 579 (P != NULL && (ret = mbedtls_mpi_copy(&ctx->P, P)) != 0) || 580 (Q != NULL && (ret = mbedtls_mpi_copy(&ctx->Q, Q)) != 0) || 581 (D != NULL && (ret = mbedtls_mpi_copy(&ctx->D, D)) != 0) || 582 (E != NULL && (ret = mbedtls_mpi_copy(&ctx->E, E)) != 0)) { 583 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret); 584 } 585 586 if (N != NULL) { 587 ctx->len = mbedtls_mpi_size(&ctx->N); 588 } 589 590 return 0; 591} 592 593int mbedtls_rsa_import_raw(mbedtls_rsa_context *ctx, 594 unsigned char const *N, size_t N_len, 595 unsigned char const *P, size_t P_len, 596 unsigned char const *Q, size_t Q_len, 597 unsigned char const *D, size_t D_len, 598 unsigned char const *E, size_t E_len) 599{ 600 int ret = 0; 601 602 if (N != NULL) { 603 MBEDTLS_MPI_CHK(mbedtls_mpi_read_binary(&ctx->N, N, N_len)); 604 ctx->len = mbedtls_mpi_size(&ctx->N); 605 } 606 607 if (P != NULL) { 608 MBEDTLS_MPI_CHK(mbedtls_mpi_read_binary(&ctx->P, P, P_len)); 609 } 610 611 if (Q != NULL) { 612 MBEDTLS_MPI_CHK(mbedtls_mpi_read_binary(&ctx->Q, Q, Q_len)); 613 } 614 615 if (D != NULL) { 616 MBEDTLS_MPI_CHK(mbedtls_mpi_read_binary(&ctx->D, D, D_len)); 617 } 618 619 if (E != NULL) { 620 MBEDTLS_MPI_CHK(mbedtls_mpi_read_binary(&ctx->E, E, E_len)); 621 } 622 623cleanup: 624 625 if (ret != 0) { 626 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret); 627 } 628 629 return 0; 630} 631 632/* 633 * Checks whether the context fields are set in such a way 634 * that the RSA primitives will be able to execute without error. 635 * It does *not* make guarantees for consistency of the parameters. 636 */ 637static int rsa_check_context(mbedtls_rsa_context const *ctx, int is_priv, 638 int blinding_needed) 639{ 640#if !defined(MBEDTLS_RSA_NO_CRT) 641 /* blinding_needed is only used for NO_CRT to decide whether 642 * P,Q need to be present or not. */ 643 ((void) blinding_needed); 644#endif 645 646 if (ctx->len != mbedtls_mpi_size(&ctx->N) || 647 ctx->len > MBEDTLS_MPI_MAX_SIZE) { 648 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 649 } 650 651 /* 652 * 1. Modular exponentiation needs positive, odd moduli. 653 */ 654 655 /* Modular exponentiation wrt. N is always used for 656 * RSA public key operations. */ 657 if (mbedtls_mpi_cmp_int(&ctx->N, 0) <= 0 || 658 mbedtls_mpi_get_bit(&ctx->N, 0) == 0) { 659 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 660 } 661 662#if !defined(MBEDTLS_RSA_NO_CRT) 663 /* Modular exponentiation for P and Q is only 664 * used for private key operations and if CRT 665 * is used. */ 666 if (is_priv && 667 (mbedtls_mpi_cmp_int(&ctx->P, 0) <= 0 || 668 mbedtls_mpi_get_bit(&ctx->P, 0) == 0 || 669 mbedtls_mpi_cmp_int(&ctx->Q, 0) <= 0 || 670 mbedtls_mpi_get_bit(&ctx->Q, 0) == 0)) { 671 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 672 } 673#endif /* !MBEDTLS_RSA_NO_CRT */ 674 675 /* 676 * 2. Exponents must be positive 677 */ 678 679 /* Always need E for public key operations */ 680 if (mbedtls_mpi_cmp_int(&ctx->E, 0) <= 0) { 681 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 682 } 683 684#if defined(MBEDTLS_RSA_NO_CRT) 685 /* For private key operations, use D or DP & DQ 686 * as (unblinded) exponents. */ 687 if (is_priv && mbedtls_mpi_cmp_int(&ctx->D, 0) <= 0) { 688 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 689 } 690#else 691 if (is_priv && 692 (mbedtls_mpi_cmp_int(&ctx->DP, 0) <= 0 || 693 mbedtls_mpi_cmp_int(&ctx->DQ, 0) <= 0)) { 694 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 695 } 696#endif /* MBEDTLS_RSA_NO_CRT */ 697 698 /* Blinding shouldn't make exponents negative either, 699 * so check that P, Q >= 1 if that hasn't yet been 700 * done as part of 1. */ 701#if defined(MBEDTLS_RSA_NO_CRT) 702 if (is_priv && blinding_needed && 703 (mbedtls_mpi_cmp_int(&ctx->P, 0) <= 0 || 704 mbedtls_mpi_cmp_int(&ctx->Q, 0) <= 0)) { 705 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 706 } 707#endif 708 709 /* It wouldn't lead to an error if it wasn't satisfied, 710 * but check for QP >= 1 nonetheless. */ 711#if !defined(MBEDTLS_RSA_NO_CRT) 712 if (is_priv && 713 mbedtls_mpi_cmp_int(&ctx->QP, 0) <= 0) { 714 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 715 } 716#endif 717 718 return 0; 719} 720 721int mbedtls_rsa_complete(mbedtls_rsa_context *ctx) 722{ 723 int ret = 0; 724 int have_N, have_P, have_Q, have_D, have_E; 725#if !defined(MBEDTLS_RSA_NO_CRT) 726 int have_DP, have_DQ, have_QP; 727#endif 728 int n_missing, pq_missing, d_missing, is_pub, is_priv; 729 730 have_N = (mbedtls_mpi_cmp_int(&ctx->N, 0) != 0); 731 have_P = (mbedtls_mpi_cmp_int(&ctx->P, 0) != 0); 732 have_Q = (mbedtls_mpi_cmp_int(&ctx->Q, 0) != 0); 733 have_D = (mbedtls_mpi_cmp_int(&ctx->D, 0) != 0); 734 have_E = (mbedtls_mpi_cmp_int(&ctx->E, 0) != 0); 735 736#if !defined(MBEDTLS_RSA_NO_CRT) 737 have_DP = (mbedtls_mpi_cmp_int(&ctx->DP, 0) != 0); 738 have_DQ = (mbedtls_mpi_cmp_int(&ctx->DQ, 0) != 0); 739 have_QP = (mbedtls_mpi_cmp_int(&ctx->QP, 0) != 0); 740#endif 741 742 /* 743 * Check whether provided parameters are enough 744 * to deduce all others. The following incomplete 745 * parameter sets for private keys are supported: 746 * 747 * (1) P, Q missing. 748 * (2) D and potentially N missing. 749 * 750 */ 751 752 n_missing = have_P && have_Q && have_D && have_E; 753 pq_missing = have_N && !have_P && !have_Q && have_D && have_E; 754 d_missing = have_P && have_Q && !have_D && have_E; 755 is_pub = have_N && !have_P && !have_Q && !have_D && have_E; 756 757 /* These three alternatives are mutually exclusive */ 758 is_priv = n_missing || pq_missing || d_missing; 759 760 if (!is_priv && !is_pub) { 761 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 762 } 763 764 /* 765 * Step 1: Deduce N if P, Q are provided. 766 */ 767 768 if (!have_N && have_P && have_Q) { 769 if ((ret = mbedtls_mpi_mul_mpi(&ctx->N, &ctx->P, 770 &ctx->Q)) != 0) { 771 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret); 772 } 773 774 ctx->len = mbedtls_mpi_size(&ctx->N); 775 } 776 777 /* 778 * Step 2: Deduce and verify all remaining core parameters. 779 */ 780 781 if (pq_missing) { 782 ret = mbedtls_rsa_deduce_primes(&ctx->N, &ctx->E, &ctx->D, 783 &ctx->P, &ctx->Q); 784 if (ret != 0) { 785 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret); 786 } 787 788 } else if (d_missing) { 789 if ((ret = mbedtls_rsa_deduce_private_exponent(&ctx->P, 790 &ctx->Q, 791 &ctx->E, 792 &ctx->D)) != 0) { 793 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret); 794 } 795 } 796 797 /* 798 * Step 3: Deduce all additional parameters specific 799 * to our current RSA implementation. 800 */ 801 802#if !defined(MBEDTLS_RSA_NO_CRT) 803 if (is_priv && !(have_DP && have_DQ && have_QP)) { 804 ret = mbedtls_rsa_deduce_crt(&ctx->P, &ctx->Q, &ctx->D, 805 &ctx->DP, &ctx->DQ, &ctx->QP); 806 if (ret != 0) { 807 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret); 808 } 809 } 810#endif /* MBEDTLS_RSA_NO_CRT */ 811 812 /* 813 * Step 3: Basic sanity checks 814 */ 815 816 return rsa_check_context(ctx, is_priv, 1); 817} 818 819int mbedtls_rsa_export_raw(const mbedtls_rsa_context *ctx, 820 unsigned char *N, size_t N_len, 821 unsigned char *P, size_t P_len, 822 unsigned char *Q, size_t Q_len, 823 unsigned char *D, size_t D_len, 824 unsigned char *E, size_t E_len) 825{ 826 int ret = 0; 827 int is_priv; 828 829 /* Check if key is private or public */ 830 is_priv = 831 mbedtls_mpi_cmp_int(&ctx->N, 0) != 0 && 832 mbedtls_mpi_cmp_int(&ctx->P, 0) != 0 && 833 mbedtls_mpi_cmp_int(&ctx->Q, 0) != 0 && 834 mbedtls_mpi_cmp_int(&ctx->D, 0) != 0 && 835 mbedtls_mpi_cmp_int(&ctx->E, 0) != 0; 836 837 if (!is_priv) { 838 /* If we're trying to export private parameters for a public key, 839 * something must be wrong. */ 840 if (P != NULL || Q != NULL || D != NULL) { 841 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 842 } 843 844 } 845 846 if (N != NULL) { 847 MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&ctx->N, N, N_len)); 848 } 849 850 if (P != NULL) { 851 MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&ctx->P, P, P_len)); 852 } 853 854 if (Q != NULL) { 855 MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&ctx->Q, Q, Q_len)); 856 } 857 858 if (D != NULL) { 859 MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&ctx->D, D, D_len)); 860 } 861 862 if (E != NULL) { 863 MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&ctx->E, E, E_len)); 864 } 865 866cleanup: 867 868 return ret; 869} 870 871int mbedtls_rsa_export(const mbedtls_rsa_context *ctx, 872 mbedtls_mpi *N, mbedtls_mpi *P, mbedtls_mpi *Q, 873 mbedtls_mpi *D, mbedtls_mpi *E) 874{ 875 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 876 int is_priv; 877 878 /* Check if key is private or public */ 879 is_priv = 880 mbedtls_mpi_cmp_int(&ctx->N, 0) != 0 && 881 mbedtls_mpi_cmp_int(&ctx->P, 0) != 0 && 882 mbedtls_mpi_cmp_int(&ctx->Q, 0) != 0 && 883 mbedtls_mpi_cmp_int(&ctx->D, 0) != 0 && 884 mbedtls_mpi_cmp_int(&ctx->E, 0) != 0; 885 886 if (!is_priv) { 887 /* If we're trying to export private parameters for a public key, 888 * something must be wrong. */ 889 if (P != NULL || Q != NULL || D != NULL) { 890 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 891 } 892 893 } 894 895 /* Export all requested core parameters. */ 896 897 if ((N != NULL && (ret = mbedtls_mpi_copy(N, &ctx->N)) != 0) || 898 (P != NULL && (ret = mbedtls_mpi_copy(P, &ctx->P)) != 0) || 899 (Q != NULL && (ret = mbedtls_mpi_copy(Q, &ctx->Q)) != 0) || 900 (D != NULL && (ret = mbedtls_mpi_copy(D, &ctx->D)) != 0) || 901 (E != NULL && (ret = mbedtls_mpi_copy(E, &ctx->E)) != 0)) { 902 return ret; 903 } 904 905 return 0; 906} 907 908/* 909 * Export CRT parameters 910 * This must also be implemented if CRT is not used, for being able to 911 * write DER encoded RSA keys. The helper function mbedtls_rsa_deduce_crt 912 * can be used in this case. 913 */ 914int mbedtls_rsa_export_crt(const mbedtls_rsa_context *ctx, 915 mbedtls_mpi *DP, mbedtls_mpi *DQ, mbedtls_mpi *QP) 916{ 917 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 918 int is_priv; 919 920 /* Check if key is private or public */ 921 is_priv = 922 mbedtls_mpi_cmp_int(&ctx->N, 0) != 0 && 923 mbedtls_mpi_cmp_int(&ctx->P, 0) != 0 && 924 mbedtls_mpi_cmp_int(&ctx->Q, 0) != 0 && 925 mbedtls_mpi_cmp_int(&ctx->D, 0) != 0 && 926 mbedtls_mpi_cmp_int(&ctx->E, 0) != 0; 927 928 if (!is_priv) { 929 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 930 } 931 932#if !defined(MBEDTLS_RSA_NO_CRT) 933 /* Export all requested blinding parameters. */ 934 if ((DP != NULL && (ret = mbedtls_mpi_copy(DP, &ctx->DP)) != 0) || 935 (DQ != NULL && (ret = mbedtls_mpi_copy(DQ, &ctx->DQ)) != 0) || 936 (QP != NULL && (ret = mbedtls_mpi_copy(QP, &ctx->QP)) != 0)) { 937 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret); 938 } 939#else 940 if ((ret = mbedtls_rsa_deduce_crt(&ctx->P, &ctx->Q, &ctx->D, 941 DP, DQ, QP)) != 0) { 942 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret); 943 } 944#endif 945 946 return 0; 947} 948 949/* 950 * Initialize an RSA context 951 */ 952void mbedtls_rsa_init(mbedtls_rsa_context *ctx) 953{ 954 memset(ctx, 0, sizeof(mbedtls_rsa_context)); 955 956 ctx->padding = MBEDTLS_RSA_PKCS_V15; 957 ctx->hash_id = MBEDTLS_MD_NONE; 958 959#if defined(MBEDTLS_THREADING_C) 960 /* Set ctx->ver to nonzero to indicate that the mutex has been 961 * initialized and will need to be freed. */ 962 ctx->ver = 1; 963 mbedtls_mutex_init(&ctx->mutex); 964#endif 965} 966 967/* 968 * Set padding for an existing RSA context 969 */ 970int mbedtls_rsa_set_padding(mbedtls_rsa_context *ctx, int padding, 971 mbedtls_md_type_t hash_id) 972{ 973 switch (padding) { 974#if defined(MBEDTLS_PKCS1_V15) 975 case MBEDTLS_RSA_PKCS_V15: 976 break; 977#endif 978 979#if defined(MBEDTLS_PKCS1_V21) 980 case MBEDTLS_RSA_PKCS_V21: 981 break; 982#endif 983 default: 984 return MBEDTLS_ERR_RSA_INVALID_PADDING; 985 } 986 987#if defined(MBEDTLS_PKCS1_V21) 988 if ((padding == MBEDTLS_RSA_PKCS_V21) && 989 (hash_id != MBEDTLS_MD_NONE)) { 990 /* Just make sure this hash is supported in this build. */ 991 if (mbedtls_md_info_from_type(hash_id) == NULL) { 992 return MBEDTLS_ERR_RSA_INVALID_PADDING; 993 } 994 } 995#endif /* MBEDTLS_PKCS1_V21 */ 996 997 ctx->padding = padding; 998 ctx->hash_id = hash_id; 999 1000 return 0; 1001} 1002 1003/* 1004 * Get padding mode of initialized RSA context 1005 */ 1006int mbedtls_rsa_get_padding_mode(const mbedtls_rsa_context *ctx) 1007{ 1008 return ctx->padding; 1009} 1010 1011/* 1012 * Get hash identifier of mbedtls_md_type_t type 1013 */ 1014int mbedtls_rsa_get_md_alg(const mbedtls_rsa_context *ctx) 1015{ 1016 return ctx->hash_id; 1017} 1018 1019/* 1020 * Get length in bits of RSA modulus 1021 */ 1022size_t mbedtls_rsa_get_bitlen(const mbedtls_rsa_context *ctx) 1023{ 1024 return mbedtls_mpi_bitlen(&ctx->N); 1025} 1026 1027/* 1028 * Get length in bytes of RSA modulus 1029 */ 1030size_t mbedtls_rsa_get_len(const mbedtls_rsa_context *ctx) 1031{ 1032 return ctx->len; 1033} 1034 1035#if defined(MBEDTLS_GENPRIME) 1036 1037/* 1038 * Generate an RSA keypair 1039 * 1040 * This generation method follows the RSA key pair generation procedure of 1041 * FIPS 186-4 if 2^16 < exponent < 2^256 and nbits = 2048 or nbits = 3072. 1042 */ 1043int mbedtls_rsa_gen_key(mbedtls_rsa_context *ctx, 1044 int (*f_rng)(void *, unsigned char *, size_t), 1045 void *p_rng, 1046 unsigned int nbits, int exponent) 1047{ 1048 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 1049 mbedtls_mpi H, G, L; 1050 int prime_quality = 0; 1051 1052 /* 1053 * If the modulus is 1024 bit long or shorter, then the security strength of 1054 * the RSA algorithm is less than or equal to 80 bits and therefore an error 1055 * rate of 2^-80 is sufficient. 1056 */ 1057 if (nbits > 1024) { 1058 prime_quality = MBEDTLS_MPI_GEN_PRIME_FLAG_LOW_ERR; 1059 } 1060 1061 mbedtls_mpi_init(&H); 1062 mbedtls_mpi_init(&G); 1063 mbedtls_mpi_init(&L); 1064 1065 if (exponent < 3 || nbits % 2 != 0) { 1066 ret = MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 1067 goto cleanup; 1068 } 1069 1070 if (nbits < MBEDTLS_RSA_GEN_KEY_MIN_BITS) { 1071 ret = MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 1072 goto cleanup; 1073 } 1074 1075 /* 1076 * find primes P and Q with Q < P so that: 1077 * 1. |P-Q| > 2^( nbits / 2 - 100 ) 1078 * 2. GCD( E, (P-1)*(Q-1) ) == 1 1079 * 3. E^-1 mod LCM(P-1, Q-1) > 2^( nbits / 2 ) 1080 */ 1081 MBEDTLS_MPI_CHK(mbedtls_mpi_lset(&ctx->E, exponent)); 1082 1083 do { 1084 MBEDTLS_MPI_CHK(mbedtls_mpi_gen_prime(&ctx->P, nbits >> 1, 1085 prime_quality, f_rng, p_rng)); 1086 1087 MBEDTLS_MPI_CHK(mbedtls_mpi_gen_prime(&ctx->Q, nbits >> 1, 1088 prime_quality, f_rng, p_rng)); 1089 1090 /* make sure the difference between p and q is not too small (FIPS 186-4 §B.3.3 step 5.4) */ 1091 MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mpi(&H, &ctx->P, &ctx->Q)); 1092 if (mbedtls_mpi_bitlen(&H) <= ((nbits >= 200) ? ((nbits >> 1) - 99) : 0)) { 1093 continue; 1094 } 1095 1096 /* not required by any standards, but some users rely on the fact that P > Q */ 1097 if (H.s < 0) { 1098 mbedtls_mpi_swap(&ctx->P, &ctx->Q); 1099 } 1100 1101 /* Temporarily replace P,Q by P-1, Q-1 */ 1102 MBEDTLS_MPI_CHK(mbedtls_mpi_sub_int(&ctx->P, &ctx->P, 1)); 1103 MBEDTLS_MPI_CHK(mbedtls_mpi_sub_int(&ctx->Q, &ctx->Q, 1)); 1104 MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&H, &ctx->P, &ctx->Q)); 1105 1106 /* check GCD( E, (P-1)*(Q-1) ) == 1 (FIPS 186-4 §B.3.1 criterion 2(a)) */ 1107 MBEDTLS_MPI_CHK(mbedtls_mpi_gcd(&G, &ctx->E, &H)); 1108 if (mbedtls_mpi_cmp_int(&G, 1) != 0) { 1109 continue; 1110 } 1111 1112 /* compute smallest possible D = E^-1 mod LCM(P-1, Q-1) (FIPS 186-4 §B.3.1 criterion 3(b)) */ 1113 MBEDTLS_MPI_CHK(mbedtls_mpi_gcd(&G, &ctx->P, &ctx->Q)); 1114 MBEDTLS_MPI_CHK(mbedtls_mpi_div_mpi(&L, NULL, &H, &G)); 1115 MBEDTLS_MPI_CHK(mbedtls_mpi_inv_mod(&ctx->D, &ctx->E, &L)); 1116 1117 if (mbedtls_mpi_bitlen(&ctx->D) <= ((nbits + 1) / 2)) { // (FIPS 186-4 §B.3.1 criterion 3(a)) 1118 continue; 1119 } 1120 1121 break; 1122 } while (1); 1123 1124 /* Restore P,Q */ 1125 MBEDTLS_MPI_CHK(mbedtls_mpi_add_int(&ctx->P, &ctx->P, 1)); 1126 MBEDTLS_MPI_CHK(mbedtls_mpi_add_int(&ctx->Q, &ctx->Q, 1)); 1127 1128 MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&ctx->N, &ctx->P, &ctx->Q)); 1129 1130 ctx->len = mbedtls_mpi_size(&ctx->N); 1131 1132#if !defined(MBEDTLS_RSA_NO_CRT) 1133 /* 1134 * DP = D mod (P - 1) 1135 * DQ = D mod (Q - 1) 1136 * QP = Q^-1 mod P 1137 */ 1138 MBEDTLS_MPI_CHK(mbedtls_rsa_deduce_crt(&ctx->P, &ctx->Q, &ctx->D, 1139 &ctx->DP, &ctx->DQ, &ctx->QP)); 1140#endif /* MBEDTLS_RSA_NO_CRT */ 1141 1142 /* Double-check */ 1143 MBEDTLS_MPI_CHK(mbedtls_rsa_check_privkey(ctx)); 1144 1145cleanup: 1146 1147 mbedtls_mpi_free(&H); 1148 mbedtls_mpi_free(&G); 1149 mbedtls_mpi_free(&L); 1150 1151 if (ret != 0) { 1152 mbedtls_rsa_free(ctx); 1153 1154 if ((-ret & ~0x7f) == 0) { 1155 ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_KEY_GEN_FAILED, ret); 1156 } 1157 return ret; 1158 } 1159 1160 return 0; 1161} 1162 1163#endif /* MBEDTLS_GENPRIME */ 1164 1165/* 1166 * Check a public RSA key 1167 */ 1168int mbedtls_rsa_check_pubkey(const mbedtls_rsa_context *ctx) 1169{ 1170 if (rsa_check_context(ctx, 0 /* public */, 0 /* no blinding */) != 0) { 1171 return MBEDTLS_ERR_RSA_KEY_CHECK_FAILED; 1172 } 1173 1174 if (mbedtls_mpi_bitlen(&ctx->N) < 128) { 1175 return MBEDTLS_ERR_RSA_KEY_CHECK_FAILED; 1176 } 1177 1178 if (mbedtls_mpi_get_bit(&ctx->E, 0) == 0 || 1179 mbedtls_mpi_bitlen(&ctx->E) < 2 || 1180 mbedtls_mpi_cmp_mpi(&ctx->E, &ctx->N) >= 0) { 1181 return MBEDTLS_ERR_RSA_KEY_CHECK_FAILED; 1182 } 1183 1184 return 0; 1185} 1186 1187/* 1188 * Check for the consistency of all fields in an RSA private key context 1189 */ 1190int mbedtls_rsa_check_privkey(const mbedtls_rsa_context *ctx) 1191{ 1192 if (mbedtls_rsa_check_pubkey(ctx) != 0 || 1193 rsa_check_context(ctx, 1 /* private */, 1 /* blinding */) != 0) { 1194 return MBEDTLS_ERR_RSA_KEY_CHECK_FAILED; 1195 } 1196 1197 if (mbedtls_rsa_validate_params(&ctx->N, &ctx->P, &ctx->Q, 1198 &ctx->D, &ctx->E, NULL, NULL) != 0) { 1199 return MBEDTLS_ERR_RSA_KEY_CHECK_FAILED; 1200 } 1201 1202#if !defined(MBEDTLS_RSA_NO_CRT) 1203 else if (mbedtls_rsa_validate_crt(&ctx->P, &ctx->Q, &ctx->D, 1204 &ctx->DP, &ctx->DQ, &ctx->QP) != 0) { 1205 return MBEDTLS_ERR_RSA_KEY_CHECK_FAILED; 1206 } 1207#endif 1208 1209 return 0; 1210} 1211 1212/* 1213 * Check if contexts holding a public and private key match 1214 */ 1215int mbedtls_rsa_check_pub_priv(const mbedtls_rsa_context *pub, 1216 const mbedtls_rsa_context *prv) 1217{ 1218 if (mbedtls_rsa_check_pubkey(pub) != 0 || 1219 mbedtls_rsa_check_privkey(prv) != 0) { 1220 return MBEDTLS_ERR_RSA_KEY_CHECK_FAILED; 1221 } 1222 1223 if (mbedtls_mpi_cmp_mpi(&pub->N, &prv->N) != 0 || 1224 mbedtls_mpi_cmp_mpi(&pub->E, &prv->E) != 0) { 1225 return MBEDTLS_ERR_RSA_KEY_CHECK_FAILED; 1226 } 1227 1228 return 0; 1229} 1230 1231/* 1232 * Do an RSA public key operation 1233 */ 1234int mbedtls_rsa_public(mbedtls_rsa_context *ctx, 1235 const unsigned char *input, 1236 unsigned char *output) 1237{ 1238 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 1239 size_t olen; 1240 mbedtls_mpi T; 1241 1242 if (rsa_check_context(ctx, 0 /* public */, 0 /* no blinding */)) { 1243 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 1244 } 1245 1246 mbedtls_mpi_init(&T); 1247 1248#if defined(MBEDTLS_THREADING_C) 1249 if ((ret = mbedtls_mutex_lock(&ctx->mutex)) != 0) { 1250 return ret; 1251 } 1252#endif 1253 1254 MBEDTLS_MPI_CHK(mbedtls_mpi_read_binary(&T, input, ctx->len)); 1255 1256 if (mbedtls_mpi_cmp_mpi(&T, &ctx->N) >= 0) { 1257 ret = MBEDTLS_ERR_MPI_BAD_INPUT_DATA; 1258 goto cleanup; 1259 } 1260 1261 olen = ctx->len; 1262 MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&T, &T, &ctx->E, &ctx->N, &ctx->RN)); 1263 MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&T, output, olen)); 1264 1265cleanup: 1266#if defined(MBEDTLS_THREADING_C) 1267 if (mbedtls_mutex_unlock(&ctx->mutex) != 0) { 1268 return MBEDTLS_ERR_THREADING_MUTEX_ERROR; 1269 } 1270#endif 1271 1272 mbedtls_mpi_free(&T); 1273 1274 if (ret != 0) { 1275 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_PUBLIC_FAILED, ret); 1276 } 1277 1278 return 0; 1279} 1280 1281/* 1282 * Generate or update blinding values, see section 10 of: 1283 * KOCHER, Paul C. Timing attacks on implementations of Diffie-Hellman, RSA, 1284 * DSS, and other systems. In : Advances in Cryptology-CRYPTO'96. Springer 1285 * Berlin Heidelberg, 1996. p. 104-113. 1286 */ 1287static int rsa_prepare_blinding(mbedtls_rsa_context *ctx, 1288 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng) 1289{ 1290 int ret, count = 0; 1291 mbedtls_mpi R; 1292 1293 mbedtls_mpi_init(&R); 1294 1295 if (ctx->Vf.p != NULL) { 1296 /* We already have blinding values, just update them by squaring */ 1297 MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&ctx->Vi, &ctx->Vi, &ctx->Vi)); 1298 MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&ctx->Vi, &ctx->Vi, &ctx->N)); 1299 MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&ctx->Vf, &ctx->Vf, &ctx->Vf)); 1300 MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&ctx->Vf, &ctx->Vf, &ctx->N)); 1301 1302 goto cleanup; 1303 } 1304 1305 /* Unblinding value: Vf = random number, invertible mod N */ 1306 do { 1307 if (count++ > 10) { 1308 ret = MBEDTLS_ERR_RSA_RNG_FAILED; 1309 goto cleanup; 1310 } 1311 1312 MBEDTLS_MPI_CHK(mbedtls_mpi_fill_random(&ctx->Vf, ctx->len - 1, f_rng, p_rng)); 1313 1314 /* Compute Vf^-1 as R * (R Vf)^-1 to avoid leaks from inv_mod. */ 1315 MBEDTLS_MPI_CHK(mbedtls_mpi_fill_random(&R, ctx->len - 1, f_rng, p_rng)); 1316 MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&ctx->Vi, &ctx->Vf, &R)); 1317 MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&ctx->Vi, &ctx->Vi, &ctx->N)); 1318 1319 /* At this point, Vi is invertible mod N if and only if both Vf and R 1320 * are invertible mod N. If one of them isn't, we don't need to know 1321 * which one, we just loop and choose new values for both of them. 1322 * (Each iteration succeeds with overwhelming probability.) */ 1323 ret = mbedtls_mpi_inv_mod(&ctx->Vi, &ctx->Vi, &ctx->N); 1324 if (ret != 0 && ret != MBEDTLS_ERR_MPI_NOT_ACCEPTABLE) { 1325 goto cleanup; 1326 } 1327 1328 } while (ret == MBEDTLS_ERR_MPI_NOT_ACCEPTABLE); 1329 1330 /* Finish the computation of Vf^-1 = R * (R Vf)^-1 */ 1331 MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&ctx->Vi, &ctx->Vi, &R)); 1332 MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&ctx->Vi, &ctx->Vi, &ctx->N)); 1333 1334 /* Blinding value: Vi = Vf^(-e) mod N 1335 * (Vi already contains Vf^-1 at this point) */ 1336 MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&ctx->Vi, &ctx->Vi, &ctx->E, &ctx->N, &ctx->RN)); 1337 1338 1339cleanup: 1340 mbedtls_mpi_free(&R); 1341 1342 return ret; 1343} 1344 1345/* 1346 * Unblind 1347 * T = T * Vf mod N 1348 */ 1349static int rsa_unblind(mbedtls_mpi *T, mbedtls_mpi *Vf, const mbedtls_mpi *N) 1350{ 1351 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 1352 const mbedtls_mpi_uint mm = mbedtls_mpi_core_montmul_init(N->p); 1353 const size_t nlimbs = N->n; 1354 const size_t tlimbs = mbedtls_mpi_core_montmul_working_limbs(nlimbs); 1355 mbedtls_mpi RR, M_T; 1356 1357 mbedtls_mpi_init(&RR); 1358 mbedtls_mpi_init(&M_T); 1359 1360 MBEDTLS_MPI_CHK(mbedtls_mpi_core_get_mont_r2_unsafe(&RR, N)); 1361 MBEDTLS_MPI_CHK(mbedtls_mpi_grow(&M_T, tlimbs)); 1362 1363 MBEDTLS_MPI_CHK(mbedtls_mpi_grow(T, nlimbs)); 1364 MBEDTLS_MPI_CHK(mbedtls_mpi_grow(Vf, nlimbs)); 1365 1366 /* T = T * Vf mod N 1367 * Reminder: montmul(A, B, N) = A * B * R^-1 mod N 1368 * Usually both operands are multiplied by R mod N beforehand (by calling 1369 * `to_mont_rep()` on them), yielding a result that's also * R mod N (aka 1370 * "in the Montgomery domain"). Here we only multiply one operand by R mod 1371 * N, so the result is directly what we want - no need to call 1372 * `from_mont_rep()` on it. */ 1373 mbedtls_mpi_core_to_mont_rep(T->p, T->p, N->p, nlimbs, mm, RR.p, M_T.p); 1374 mbedtls_mpi_core_montmul(T->p, T->p, Vf->p, nlimbs, N->p, nlimbs, mm, M_T.p); 1375 1376cleanup: 1377 1378 mbedtls_mpi_free(&RR); 1379 mbedtls_mpi_free(&M_T); 1380 1381 return ret; 1382} 1383 1384/* 1385 * Exponent blinding supposed to prevent side-channel attacks using multiple 1386 * traces of measurements to recover the RSA key. The more collisions are there, 1387 * the more bits of the key can be recovered. See [3]. 1388 * 1389 * Collecting n collisions with m bit long blinding value requires 2^(m-m/n) 1390 * observations on average. 1391 * 1392 * For example with 28 byte blinding to achieve 2 collisions the adversary has 1393 * to make 2^112 observations on average. 1394 * 1395 * (With the currently (as of 2017 April) known best algorithms breaking 2048 1396 * bit RSA requires approximately as much time as trying out 2^112 random keys. 1397 * Thus in this sense with 28 byte blinding the security is not reduced by 1398 * side-channel attacks like the one in [3]) 1399 * 1400 * This countermeasure does not help if the key recovery is possible with a 1401 * single trace. 1402 */ 1403#define RSA_EXPONENT_BLINDING 28 1404 1405/* 1406 * Do an RSA private key operation 1407 */ 1408int mbedtls_rsa_private(mbedtls_rsa_context *ctx, 1409 int (*f_rng)(void *, unsigned char *, size_t), 1410 void *p_rng, 1411 const unsigned char *input, 1412 unsigned char *output) 1413{ 1414 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 1415 size_t olen; 1416 1417 /* Temporary holding the result */ 1418 mbedtls_mpi T; 1419 1420 /* Temporaries holding P-1, Q-1 and the 1421 * exponent blinding factor, respectively. */ 1422 mbedtls_mpi P1, Q1, R; 1423 1424#if !defined(MBEDTLS_RSA_NO_CRT) 1425 /* Temporaries holding the results mod p resp. mod q. */ 1426 mbedtls_mpi TP, TQ; 1427 1428 /* Temporaries holding the blinded exponents for 1429 * the mod p resp. mod q computation (if used). */ 1430 mbedtls_mpi DP_blind, DQ_blind; 1431#else 1432 /* Temporary holding the blinded exponent (if used). */ 1433 mbedtls_mpi D_blind; 1434#endif /* MBEDTLS_RSA_NO_CRT */ 1435 1436 /* Temporaries holding the initial input and the double 1437 * checked result; should be the same in the end. */ 1438 mbedtls_mpi input_blinded, check_result_blinded; 1439 1440 if (f_rng == NULL) { 1441 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 1442 } 1443 1444 if (rsa_check_context(ctx, 1 /* private key checks */, 1445 1 /* blinding on */) != 0) { 1446 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 1447 } 1448 1449#if defined(MBEDTLS_THREADING_C) 1450 if ((ret = mbedtls_mutex_lock(&ctx->mutex)) != 0) { 1451 return ret; 1452 } 1453#endif 1454 1455 /* MPI Initialization */ 1456 mbedtls_mpi_init(&T); 1457 1458 mbedtls_mpi_init(&P1); 1459 mbedtls_mpi_init(&Q1); 1460 mbedtls_mpi_init(&R); 1461 1462#if defined(MBEDTLS_RSA_NO_CRT) 1463 mbedtls_mpi_init(&D_blind); 1464#else 1465 mbedtls_mpi_init(&DP_blind); 1466 mbedtls_mpi_init(&DQ_blind); 1467#endif 1468 1469#if !defined(MBEDTLS_RSA_NO_CRT) 1470 mbedtls_mpi_init(&TP); mbedtls_mpi_init(&TQ); 1471#endif 1472 1473 mbedtls_mpi_init(&input_blinded); 1474 mbedtls_mpi_init(&check_result_blinded); 1475 1476 /* End of MPI initialization */ 1477 1478 MBEDTLS_MPI_CHK(mbedtls_mpi_read_binary(&T, input, ctx->len)); 1479 if (mbedtls_mpi_cmp_mpi(&T, &ctx->N) >= 0) { 1480 ret = MBEDTLS_ERR_MPI_BAD_INPUT_DATA; 1481 goto cleanup; 1482 } 1483 1484 /* 1485 * Blinding 1486 * T = T * Vi mod N 1487 */ 1488 MBEDTLS_MPI_CHK(rsa_prepare_blinding(ctx, f_rng, p_rng)); 1489 MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&T, &T, &ctx->Vi)); 1490 MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&T, &T, &ctx->N)); 1491 1492 MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&input_blinded, &T)); 1493 1494 /* 1495 * Exponent blinding 1496 */ 1497 MBEDTLS_MPI_CHK(mbedtls_mpi_sub_int(&P1, &ctx->P, 1)); 1498 MBEDTLS_MPI_CHK(mbedtls_mpi_sub_int(&Q1, &ctx->Q, 1)); 1499 1500#if defined(MBEDTLS_RSA_NO_CRT) 1501 /* 1502 * D_blind = ( P - 1 ) * ( Q - 1 ) * R + D 1503 */ 1504 MBEDTLS_MPI_CHK(mbedtls_mpi_fill_random(&R, RSA_EXPONENT_BLINDING, 1505 f_rng, p_rng)); 1506 MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&D_blind, &P1, &Q1)); 1507 MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&D_blind, &D_blind, &R)); 1508 MBEDTLS_MPI_CHK(mbedtls_mpi_add_mpi(&D_blind, &D_blind, &ctx->D)); 1509#else 1510 /* 1511 * DP_blind = ( P - 1 ) * R + DP 1512 */ 1513 MBEDTLS_MPI_CHK(mbedtls_mpi_fill_random(&R, RSA_EXPONENT_BLINDING, 1514 f_rng, p_rng)); 1515 MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&DP_blind, &P1, &R)); 1516 MBEDTLS_MPI_CHK(mbedtls_mpi_add_mpi(&DP_blind, &DP_blind, 1517 &ctx->DP)); 1518 1519 /* 1520 * DQ_blind = ( Q - 1 ) * R + DQ 1521 */ 1522 MBEDTLS_MPI_CHK(mbedtls_mpi_fill_random(&R, RSA_EXPONENT_BLINDING, 1523 f_rng, p_rng)); 1524 MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&DQ_blind, &Q1, &R)); 1525 MBEDTLS_MPI_CHK(mbedtls_mpi_add_mpi(&DQ_blind, &DQ_blind, 1526 &ctx->DQ)); 1527#endif /* MBEDTLS_RSA_NO_CRT */ 1528 1529#if defined(MBEDTLS_RSA_NO_CRT) 1530 MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&T, &T, &D_blind, &ctx->N, &ctx->RN)); 1531#else 1532 /* 1533 * Faster decryption using the CRT 1534 * 1535 * TP = input ^ dP mod P 1536 * TQ = input ^ dQ mod Q 1537 */ 1538 1539 MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&TP, &T, &DP_blind, &ctx->P, &ctx->RP)); 1540 MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&TQ, &T, &DQ_blind, &ctx->Q, &ctx->RQ)); 1541 1542 /* 1543 * T = (TP - TQ) * (Q^-1 mod P) mod P 1544 */ 1545 MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mpi(&T, &TP, &TQ)); 1546 MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&TP, &T, &ctx->QP)); 1547 MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&T, &TP, &ctx->P)); 1548 1549 /* 1550 * T = TQ + T * Q 1551 */ 1552 MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&TP, &T, &ctx->Q)); 1553 MBEDTLS_MPI_CHK(mbedtls_mpi_add_mpi(&T, &TQ, &TP)); 1554#endif /* MBEDTLS_RSA_NO_CRT */ 1555 1556 /* Verify the result to prevent glitching attacks. */ 1557 MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&check_result_blinded, &T, &ctx->E, 1558 &ctx->N, &ctx->RN)); 1559 if (mbedtls_mpi_cmp_mpi(&check_result_blinded, &input_blinded) != 0) { 1560 ret = MBEDTLS_ERR_RSA_VERIFY_FAILED; 1561 goto cleanup; 1562 } 1563 1564 /* 1565 * Unblind 1566 * T = T * Vf mod N 1567 */ 1568 MBEDTLS_MPI_CHK(rsa_unblind(&T, &ctx->Vf, &ctx->N)); 1569 1570 olen = ctx->len; 1571 MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&T, output, olen)); 1572 1573cleanup: 1574#if defined(MBEDTLS_THREADING_C) 1575 if (mbedtls_mutex_unlock(&ctx->mutex) != 0) { 1576 return MBEDTLS_ERR_THREADING_MUTEX_ERROR; 1577 } 1578#endif 1579 1580 mbedtls_mpi_free(&P1); 1581 mbedtls_mpi_free(&Q1); 1582 mbedtls_mpi_free(&R); 1583 1584#if defined(MBEDTLS_RSA_NO_CRT) 1585 mbedtls_mpi_free(&D_blind); 1586#else 1587 mbedtls_mpi_free(&DP_blind); 1588 mbedtls_mpi_free(&DQ_blind); 1589#endif 1590 1591 mbedtls_mpi_free(&T); 1592 1593#if !defined(MBEDTLS_RSA_NO_CRT) 1594 mbedtls_mpi_free(&TP); mbedtls_mpi_free(&TQ); 1595#endif 1596 1597 mbedtls_mpi_free(&check_result_blinded); 1598 mbedtls_mpi_free(&input_blinded); 1599 1600 if (ret != 0 && ret >= -0x007f) { 1601 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_PRIVATE_FAILED, ret); 1602 } 1603 1604 return ret; 1605} 1606 1607#if defined(MBEDTLS_PKCS1_V21) 1608/** 1609 * Generate and apply the MGF1 operation (from PKCS#1 v2.1) to a buffer. 1610 * 1611 * \param dst buffer to mask 1612 * \param dlen length of destination buffer 1613 * \param src source of the mask generation 1614 * \param slen length of the source buffer 1615 * \param md_alg message digest to use 1616 */ 1617static int mgf_mask(unsigned char *dst, size_t dlen, unsigned char *src, 1618 size_t slen, mbedtls_md_type_t md_alg) 1619{ 1620 unsigned char counter[4]; 1621 unsigned char *p; 1622 unsigned int hlen; 1623 size_t i, use_len; 1624 unsigned char mask[MBEDTLS_MD_MAX_SIZE]; 1625 int ret = 0; 1626 const mbedtls_md_info_t *md_info; 1627 mbedtls_md_context_t md_ctx; 1628 1629 mbedtls_md_init(&md_ctx); 1630 md_info = mbedtls_md_info_from_type(md_alg); 1631 if (md_info == NULL) { 1632 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 1633 } 1634 1635 mbedtls_md_init(&md_ctx); 1636 if ((ret = mbedtls_md_setup(&md_ctx, md_info, 0)) != 0) { 1637 goto exit; 1638 } 1639 1640 hlen = mbedtls_md_get_size(md_info); 1641 1642 memset(mask, 0, sizeof(mask)); 1643 memset(counter, 0, 4); 1644 1645 /* Generate and apply dbMask */ 1646 p = dst; 1647 1648 while (dlen > 0) { 1649 use_len = hlen; 1650 if (dlen < hlen) { 1651 use_len = dlen; 1652 } 1653 1654 if ((ret = mbedtls_md_starts(&md_ctx)) != 0) { 1655 goto exit; 1656 } 1657 if ((ret = mbedtls_md_update(&md_ctx, src, slen)) != 0) { 1658 goto exit; 1659 } 1660 if ((ret = mbedtls_md_update(&md_ctx, counter, 4)) != 0) { 1661 goto exit; 1662 } 1663 if ((ret = mbedtls_md_finish(&md_ctx, mask)) != 0) { 1664 goto exit; 1665 } 1666 1667 for (i = 0; i < use_len; ++i) { 1668 *p++ ^= mask[i]; 1669 } 1670 1671 counter[3]++; 1672 1673 dlen -= use_len; 1674 } 1675 1676exit: 1677 mbedtls_platform_zeroize(mask, sizeof(mask)); 1678 mbedtls_md_free(&md_ctx); 1679 1680 return ret; 1681} 1682 1683/** 1684 * Generate Hash(M') as in RFC 8017 page 43 points 5 and 6. 1685 * 1686 * \param hash the input hash 1687 * \param hlen length of the input hash 1688 * \param salt the input salt 1689 * \param slen length of the input salt 1690 * \param out the output buffer - must be large enough for \p md_alg 1691 * \param md_alg message digest to use 1692 */ 1693static int hash_mprime(const unsigned char *hash, size_t hlen, 1694 const unsigned char *salt, size_t slen, 1695 unsigned char *out, mbedtls_md_type_t md_alg) 1696{ 1697 const unsigned char zeros[8] = { 0, 0, 0, 0, 0, 0, 0, 0 }; 1698 1699 mbedtls_md_context_t md_ctx; 1700 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 1701 1702 const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type(md_alg); 1703 if (md_info == NULL) { 1704 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 1705 } 1706 1707 mbedtls_md_init(&md_ctx); 1708 if ((ret = mbedtls_md_setup(&md_ctx, md_info, 0)) != 0) { 1709 goto exit; 1710 } 1711 if ((ret = mbedtls_md_starts(&md_ctx)) != 0) { 1712 goto exit; 1713 } 1714 if ((ret = mbedtls_md_update(&md_ctx, zeros, sizeof(zeros))) != 0) { 1715 goto exit; 1716 } 1717 if ((ret = mbedtls_md_update(&md_ctx, hash, hlen)) != 0) { 1718 goto exit; 1719 } 1720 if ((ret = mbedtls_md_update(&md_ctx, salt, slen)) != 0) { 1721 goto exit; 1722 } 1723 if ((ret = mbedtls_md_finish(&md_ctx, out)) != 0) { 1724 goto exit; 1725 } 1726 1727exit: 1728 mbedtls_md_free(&md_ctx); 1729 1730 return ret; 1731} 1732 1733/** 1734 * Compute a hash. 1735 * 1736 * \param md_alg algorithm to use 1737 * \param input input message to hash 1738 * \param ilen input length 1739 * \param output the output buffer - must be large enough for \p md_alg 1740 */ 1741static int compute_hash(mbedtls_md_type_t md_alg, 1742 const unsigned char *input, size_t ilen, 1743 unsigned char *output) 1744{ 1745 const mbedtls_md_info_t *md_info; 1746 1747 md_info = mbedtls_md_info_from_type(md_alg); 1748 if (md_info == NULL) { 1749 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 1750 } 1751 1752 return mbedtls_md(md_info, input, ilen, output); 1753} 1754#endif /* MBEDTLS_PKCS1_V21 */ 1755 1756#if defined(MBEDTLS_PKCS1_V21) 1757/* 1758 * Implementation of the PKCS#1 v2.1 RSAES-OAEP-ENCRYPT function 1759 */ 1760int mbedtls_rsa_rsaes_oaep_encrypt(mbedtls_rsa_context *ctx, 1761 int (*f_rng)(void *, unsigned char *, size_t), 1762 void *p_rng, 1763 const unsigned char *label, size_t label_len, 1764 size_t ilen, 1765 const unsigned char *input, 1766 unsigned char *output) 1767{ 1768 size_t olen; 1769 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 1770 unsigned char *p = output; 1771 unsigned int hlen; 1772 1773 if (f_rng == NULL) { 1774 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 1775 } 1776 1777 hlen = mbedtls_md_get_size_from_type((mbedtls_md_type_t) ctx->hash_id); 1778 if (hlen == 0) { 1779 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 1780 } 1781 1782 olen = ctx->len; 1783 1784 /* first comparison checks for overflow */ 1785 if (ilen + 2 * hlen + 2 < ilen || olen < ilen + 2 * hlen + 2) { 1786 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 1787 } 1788 1789 memset(output, 0, olen); 1790 1791 *p++ = 0; 1792 1793 /* Generate a random octet string seed */ 1794 if ((ret = f_rng(p_rng, p, hlen)) != 0) { 1795 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_RNG_FAILED, ret); 1796 } 1797 1798 p += hlen; 1799 1800 /* Construct DB */ 1801 ret = compute_hash((mbedtls_md_type_t) ctx->hash_id, label, label_len, p); 1802 if (ret != 0) { 1803 return ret; 1804 } 1805 p += hlen; 1806 p += olen - 2 * hlen - 2 - ilen; 1807 *p++ = 1; 1808 if (ilen != 0) { 1809 memcpy(p, input, ilen); 1810 } 1811 1812 /* maskedDB: Apply dbMask to DB */ 1813 if ((ret = mgf_mask(output + hlen + 1, olen - hlen - 1, output + 1, hlen, 1814 (mbedtls_md_type_t) ctx->hash_id)) != 0) { 1815 return ret; 1816 } 1817 1818 /* maskedSeed: Apply seedMask to seed */ 1819 if ((ret = mgf_mask(output + 1, hlen, output + hlen + 1, olen - hlen - 1, 1820 (mbedtls_md_type_t) ctx->hash_id)) != 0) { 1821 return ret; 1822 } 1823 1824 return mbedtls_rsa_public(ctx, output, output); 1825} 1826#endif /* MBEDTLS_PKCS1_V21 */ 1827 1828#if defined(MBEDTLS_PKCS1_V15) 1829/* 1830 * Implementation of the PKCS#1 v2.1 RSAES-PKCS1-V1_5-ENCRYPT function 1831 */ 1832int mbedtls_rsa_rsaes_pkcs1_v15_encrypt(mbedtls_rsa_context *ctx, 1833 int (*f_rng)(void *, unsigned char *, size_t), 1834 void *p_rng, size_t ilen, 1835 const unsigned char *input, 1836 unsigned char *output) 1837{ 1838 size_t nb_pad, olen; 1839 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 1840 unsigned char *p = output; 1841 1842 olen = ctx->len; 1843 1844 /* first comparison checks for overflow */ 1845 if (ilen + 11 < ilen || olen < ilen + 11) { 1846 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 1847 } 1848 1849 nb_pad = olen - 3 - ilen; 1850 1851 *p++ = 0; 1852 1853 if (f_rng == NULL) { 1854 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 1855 } 1856 1857 *p++ = MBEDTLS_RSA_CRYPT; 1858 1859 while (nb_pad-- > 0) { 1860 int rng_dl = 100; 1861 1862 do { 1863 ret = f_rng(p_rng, p, 1); 1864 } while (*p == 0 && --rng_dl && ret == 0); 1865 1866 /* Check if RNG failed to generate data */ 1867 if (rng_dl == 0 || ret != 0) { 1868 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_RNG_FAILED, ret); 1869 } 1870 1871 p++; 1872 } 1873 1874 *p++ = 0; 1875 if (ilen != 0) { 1876 memcpy(p, input, ilen); 1877 } 1878 1879 return mbedtls_rsa_public(ctx, output, output); 1880} 1881#endif /* MBEDTLS_PKCS1_V15 */ 1882 1883/* 1884 * Add the message padding, then do an RSA operation 1885 */ 1886int mbedtls_rsa_pkcs1_encrypt(mbedtls_rsa_context *ctx, 1887 int (*f_rng)(void *, unsigned char *, size_t), 1888 void *p_rng, 1889 size_t ilen, 1890 const unsigned char *input, 1891 unsigned char *output) 1892{ 1893 switch (ctx->padding) { 1894#if defined(MBEDTLS_PKCS1_V15) 1895 case MBEDTLS_RSA_PKCS_V15: 1896 return mbedtls_rsa_rsaes_pkcs1_v15_encrypt(ctx, f_rng, p_rng, 1897 ilen, input, output); 1898#endif 1899 1900#if defined(MBEDTLS_PKCS1_V21) 1901 case MBEDTLS_RSA_PKCS_V21: 1902 return mbedtls_rsa_rsaes_oaep_encrypt(ctx, f_rng, p_rng, NULL, 0, 1903 ilen, input, output); 1904#endif 1905 1906 default: 1907 return MBEDTLS_ERR_RSA_INVALID_PADDING; 1908 } 1909} 1910 1911#if defined(MBEDTLS_PKCS1_V21) 1912/* 1913 * Implementation of the PKCS#1 v2.1 RSAES-OAEP-DECRYPT function 1914 */ 1915int mbedtls_rsa_rsaes_oaep_decrypt(mbedtls_rsa_context *ctx, 1916 int (*f_rng)(void *, unsigned char *, size_t), 1917 void *p_rng, 1918 const unsigned char *label, size_t label_len, 1919 size_t *olen, 1920 const unsigned char *input, 1921 unsigned char *output, 1922 size_t output_max_len) 1923{ 1924 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 1925 size_t ilen, i, pad_len; 1926 unsigned char *p; 1927 mbedtls_ct_condition_t bad, in_padding; 1928 unsigned char buf[MBEDTLS_MPI_MAX_SIZE]; 1929 unsigned char lhash[MBEDTLS_MD_MAX_SIZE]; 1930 unsigned int hlen; 1931 1932 /* 1933 * Parameters sanity checks 1934 */ 1935 if (ctx->padding != MBEDTLS_RSA_PKCS_V21) { 1936 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 1937 } 1938 1939 ilen = ctx->len; 1940 1941 if (ilen < 16 || ilen > sizeof(buf)) { 1942 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 1943 } 1944 1945 hlen = mbedtls_md_get_size_from_type((mbedtls_md_type_t) ctx->hash_id); 1946 if (hlen == 0) { 1947 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 1948 } 1949 1950 // checking for integer underflow 1951 if (2 * hlen + 2 > ilen) { 1952 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 1953 } 1954 1955 /* 1956 * RSA operation 1957 */ 1958 ret = mbedtls_rsa_private(ctx, f_rng, p_rng, input, buf); 1959 1960 if (ret != 0) { 1961 goto cleanup; 1962 } 1963 1964 /* 1965 * Unmask data and generate lHash 1966 */ 1967 /* seed: Apply seedMask to maskedSeed */ 1968 if ((ret = mgf_mask(buf + 1, hlen, buf + hlen + 1, ilen - hlen - 1, 1969 (mbedtls_md_type_t) ctx->hash_id)) != 0 || 1970 /* DB: Apply dbMask to maskedDB */ 1971 (ret = mgf_mask(buf + hlen + 1, ilen - hlen - 1, buf + 1, hlen, 1972 (mbedtls_md_type_t) ctx->hash_id)) != 0) { 1973 goto cleanup; 1974 } 1975 1976 /* Generate lHash */ 1977 ret = compute_hash((mbedtls_md_type_t) ctx->hash_id, 1978 label, label_len, lhash); 1979 if (ret != 0) { 1980 goto cleanup; 1981 } 1982 1983 /* 1984 * Check contents, in "constant-time" 1985 */ 1986 p = buf; 1987 1988 bad = mbedtls_ct_bool(*p++); /* First byte must be 0 */ 1989 1990 p += hlen; /* Skip seed */ 1991 1992 /* Check lHash */ 1993 bad = mbedtls_ct_bool_or(bad, mbedtls_ct_bool(mbedtls_ct_memcmp(lhash, p, hlen))); 1994 p += hlen; 1995 1996 /* Get zero-padding len, but always read till end of buffer 1997 * (minus one, for the 01 byte) */ 1998 pad_len = 0; 1999 in_padding = MBEDTLS_CT_TRUE; 2000 for (i = 0; i < ilen - 2 * hlen - 2; i++) { 2001 in_padding = mbedtls_ct_bool_and(in_padding, mbedtls_ct_uint_eq(p[i], 0)); 2002 pad_len += mbedtls_ct_uint_if_else_0(in_padding, 1); 2003 } 2004 2005 p += pad_len; 2006 bad = mbedtls_ct_bool_or(bad, mbedtls_ct_uint_ne(*p++, 0x01)); 2007 2008 /* 2009 * The only information "leaked" is whether the padding was correct or not 2010 * (eg, no data is copied if it was not correct). This meets the 2011 * recommendations in PKCS#1 v2.2: an opponent cannot distinguish between 2012 * the different error conditions. 2013 */ 2014 if (bad != MBEDTLS_CT_FALSE) { 2015 ret = MBEDTLS_ERR_RSA_INVALID_PADDING; 2016 goto cleanup; 2017 } 2018 2019 if (ilen - ((size_t) (p - buf)) > output_max_len) { 2020 ret = MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE; 2021 goto cleanup; 2022 } 2023 2024 *olen = ilen - ((size_t) (p - buf)); 2025 if (*olen != 0) { 2026 memcpy(output, p, *olen); 2027 } 2028 ret = 0; 2029 2030cleanup: 2031 mbedtls_platform_zeroize(buf, sizeof(buf)); 2032 mbedtls_platform_zeroize(lhash, sizeof(lhash)); 2033 2034 return ret; 2035} 2036#endif /* MBEDTLS_PKCS1_V21 */ 2037 2038#if defined(MBEDTLS_PKCS1_V15) 2039/* 2040 * Implementation of the PKCS#1 v2.1 RSAES-PKCS1-V1_5-DECRYPT function 2041 */ 2042int mbedtls_rsa_rsaes_pkcs1_v15_decrypt(mbedtls_rsa_context *ctx, 2043 int (*f_rng)(void *, unsigned char *, size_t), 2044 void *p_rng, 2045 size_t *olen, 2046 const unsigned char *input, 2047 unsigned char *output, 2048 size_t output_max_len) 2049{ 2050 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 2051 size_t ilen; 2052 unsigned char buf[MBEDTLS_MPI_MAX_SIZE]; 2053 2054 ilen = ctx->len; 2055 2056 if (ctx->padding != MBEDTLS_RSA_PKCS_V15) { 2057 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2058 } 2059 2060 if (ilen < 16 || ilen > sizeof(buf)) { 2061 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2062 } 2063 2064 ret = mbedtls_rsa_private(ctx, f_rng, p_rng, input, buf); 2065 2066 if (ret != 0) { 2067 goto cleanup; 2068 } 2069 2070 ret = mbedtls_ct_rsaes_pkcs1_v15_unpadding(buf, ilen, 2071 output, output_max_len, olen); 2072 2073cleanup: 2074 mbedtls_platform_zeroize(buf, sizeof(buf)); 2075 2076 return ret; 2077} 2078#endif /* MBEDTLS_PKCS1_V15 */ 2079 2080/* 2081 * Do an RSA operation, then remove the message padding 2082 */ 2083int mbedtls_rsa_pkcs1_decrypt(mbedtls_rsa_context *ctx, 2084 int (*f_rng)(void *, unsigned char *, size_t), 2085 void *p_rng, 2086 size_t *olen, 2087 const unsigned char *input, 2088 unsigned char *output, 2089 size_t output_max_len) 2090{ 2091 switch (ctx->padding) { 2092#if defined(MBEDTLS_PKCS1_V15) 2093 case MBEDTLS_RSA_PKCS_V15: 2094 return mbedtls_rsa_rsaes_pkcs1_v15_decrypt(ctx, f_rng, p_rng, olen, 2095 input, output, output_max_len); 2096#endif 2097 2098#if defined(MBEDTLS_PKCS1_V21) 2099 case MBEDTLS_RSA_PKCS_V21: 2100 return mbedtls_rsa_rsaes_oaep_decrypt(ctx, f_rng, p_rng, NULL, 0, 2101 olen, input, output, 2102 output_max_len); 2103#endif 2104 2105 default: 2106 return MBEDTLS_ERR_RSA_INVALID_PADDING; 2107 } 2108} 2109 2110#if defined(MBEDTLS_PKCS1_V21) 2111static int rsa_rsassa_pss_sign_no_mode_check(mbedtls_rsa_context *ctx, 2112 int (*f_rng)(void *, unsigned char *, size_t), 2113 void *p_rng, 2114 mbedtls_md_type_t md_alg, 2115 unsigned int hashlen, 2116 const unsigned char *hash, 2117 int saltlen, 2118 unsigned char *sig) 2119{ 2120 size_t olen; 2121 unsigned char *p = sig; 2122 unsigned char *salt = NULL; 2123 size_t slen, min_slen, hlen, offset = 0; 2124 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 2125 size_t msb; 2126 mbedtls_md_type_t hash_id; 2127 2128 if ((md_alg != MBEDTLS_MD_NONE || hashlen != 0) && hash == NULL) { 2129 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2130 } 2131 2132 if (f_rng == NULL) { 2133 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2134 } 2135 2136 olen = ctx->len; 2137 2138 if (md_alg != MBEDTLS_MD_NONE) { 2139 /* Gather length of hash to sign */ 2140 size_t exp_hashlen = mbedtls_md_get_size_from_type(md_alg); 2141 if (exp_hashlen == 0) { 2142 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2143 } 2144 2145 if (hashlen != exp_hashlen) { 2146 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2147 } 2148 } 2149 2150 hash_id = (mbedtls_md_type_t) ctx->hash_id; 2151 if (hash_id == MBEDTLS_MD_NONE) { 2152 hash_id = md_alg; 2153 } 2154 hlen = mbedtls_md_get_size_from_type(hash_id); 2155 if (hlen == 0) { 2156 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2157 } 2158 2159 if (saltlen == MBEDTLS_RSA_SALT_LEN_ANY) { 2160 /* Calculate the largest possible salt length, up to the hash size. 2161 * Normally this is the hash length, which is the maximum salt length 2162 * according to FIPS 185-4 §5.5 (e) and common practice. If there is not 2163 * enough room, use the maximum salt length that fits. The constraint is 2164 * that the hash length plus the salt length plus 2 bytes must be at most 2165 * the key length. This complies with FIPS 186-4 §5.5 (e) and RFC 8017 2166 * (PKCS#1 v2.2) §9.1.1 step 3. */ 2167 min_slen = hlen - 2; 2168 if (olen < hlen + min_slen + 2) { 2169 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2170 } else if (olen >= hlen + hlen + 2) { 2171 slen = hlen; 2172 } else { 2173 slen = olen - hlen - 2; 2174 } 2175 } else if ((saltlen < 0) || (saltlen + hlen + 2 > olen)) { 2176 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2177 } else { 2178 slen = (size_t) saltlen; 2179 } 2180 2181 memset(sig, 0, olen); 2182 2183 /* Note: EMSA-PSS encoding is over the length of N - 1 bits */ 2184 msb = mbedtls_mpi_bitlen(&ctx->N) - 1; 2185 p += olen - hlen - slen - 2; 2186 *p++ = 0x01; 2187 2188 /* Generate salt of length slen in place in the encoded message */ 2189 salt = p; 2190 if ((ret = f_rng(p_rng, salt, slen)) != 0) { 2191 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_RSA_RNG_FAILED, ret); 2192 } 2193 2194 p += slen; 2195 2196 /* Generate H = Hash( M' ) */ 2197 ret = hash_mprime(hash, hashlen, salt, slen, p, (mbedtls_md_type_t)ctx->hash_id); 2198 if (ret != 0) { 2199 return ret; 2200 } 2201 2202 /* Compensate for boundary condition when applying mask */ 2203 if (msb % 8 == 0) { 2204 offset = 1; 2205 } 2206 2207 /* maskedDB: Apply dbMask to DB */ 2208 ret = mgf_mask(sig + offset, olen - hlen - 1 - offset, p, hlen, 2209 (mbedtls_md_type_t)ctx->hash_id); 2210 if (ret != 0) { 2211 return ret; 2212 } 2213 2214 msb = mbedtls_mpi_bitlen(&ctx->N) - 1; 2215 sig[0] &= 0xFF >> (olen * 8 - msb); 2216 2217 p += hlen; 2218 *p++ = 0xBC; 2219 2220 return mbedtls_rsa_private(ctx, f_rng, p_rng, sig, sig); 2221} 2222 2223static int rsa_rsassa_pss_sign(mbedtls_rsa_context *ctx, 2224 int (*f_rng)(void *, unsigned char *, size_t), 2225 void *p_rng, 2226 mbedtls_md_type_t md_alg, 2227 unsigned int hashlen, 2228 const unsigned char *hash, 2229 int saltlen, 2230 unsigned char *sig) 2231{ 2232 if (ctx->padding != MBEDTLS_RSA_PKCS_V21) { 2233 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2234 } 2235 if ((ctx->hash_id == MBEDTLS_MD_NONE) && (md_alg == MBEDTLS_MD_NONE)) { 2236 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2237 } 2238 return rsa_rsassa_pss_sign_no_mode_check(ctx, f_rng, p_rng, md_alg, hashlen, hash, saltlen, 2239 sig); 2240} 2241 2242int mbedtls_rsa_rsassa_pss_sign_no_mode_check(mbedtls_rsa_context *ctx, 2243 int (*f_rng)(void *, unsigned char *, size_t), 2244 void *p_rng, 2245 mbedtls_md_type_t md_alg, 2246 unsigned int hashlen, 2247 const unsigned char *hash, 2248 unsigned char *sig) 2249{ 2250 return rsa_rsassa_pss_sign_no_mode_check(ctx, f_rng, p_rng, md_alg, 2251 hashlen, hash, MBEDTLS_RSA_SALT_LEN_ANY, sig); 2252} 2253 2254/* 2255 * Implementation of the PKCS#1 v2.1 RSASSA-PSS-SIGN function with 2256 * the option to pass in the salt length. 2257 */ 2258int mbedtls_rsa_rsassa_pss_sign_ext(mbedtls_rsa_context *ctx, 2259 int (*f_rng)(void *, unsigned char *, size_t), 2260 void *p_rng, 2261 mbedtls_md_type_t md_alg, 2262 unsigned int hashlen, 2263 const unsigned char *hash, 2264 int saltlen, 2265 unsigned char *sig) 2266{ 2267 return rsa_rsassa_pss_sign(ctx, f_rng, p_rng, md_alg, 2268 hashlen, hash, saltlen, sig); 2269} 2270 2271/* 2272 * Implementation of the PKCS#1 v2.1 RSASSA-PSS-SIGN function 2273 */ 2274int mbedtls_rsa_rsassa_pss_sign(mbedtls_rsa_context *ctx, 2275 int (*f_rng)(void *, unsigned char *, size_t), 2276 void *p_rng, 2277 mbedtls_md_type_t md_alg, 2278 unsigned int hashlen, 2279 const unsigned char *hash, 2280 unsigned char *sig) 2281{ 2282 return rsa_rsassa_pss_sign(ctx, f_rng, p_rng, md_alg, 2283 hashlen, hash, MBEDTLS_RSA_SALT_LEN_ANY, sig); 2284} 2285#endif /* MBEDTLS_PKCS1_V21 */ 2286 2287#if defined(MBEDTLS_PKCS1_V15) 2288/* 2289 * Implementation of the PKCS#1 v2.1 RSASSA-PKCS1-V1_5-SIGN function 2290 */ 2291 2292/* Construct a PKCS v1.5 encoding of a hashed message 2293 * 2294 * This is used both for signature generation and verification. 2295 * 2296 * Parameters: 2297 * - md_alg: Identifies the hash algorithm used to generate the given hash; 2298 * MBEDTLS_MD_NONE if raw data is signed. 2299 * - hashlen: Length of hash. Must match md_alg if that's not NONE. 2300 * - hash: Buffer containing the hashed message or the raw data. 2301 * - dst_len: Length of the encoded message. 2302 * - dst: Buffer to hold the encoded message. 2303 * 2304 * Assumptions: 2305 * - hash has size hashlen. 2306 * - dst points to a buffer of size at least dst_len. 2307 * 2308 */ 2309static int rsa_rsassa_pkcs1_v15_encode(mbedtls_md_type_t md_alg, 2310 unsigned int hashlen, 2311 const unsigned char *hash, 2312 size_t dst_len, 2313 unsigned char *dst) 2314{ 2315 size_t oid_size = 0; 2316 size_t nb_pad = dst_len; 2317 unsigned char *p = dst; 2318 const char *oid = NULL; 2319 2320 /* Are we signing hashed or raw data? */ 2321 if (md_alg != MBEDTLS_MD_NONE) { 2322 unsigned char md_size = mbedtls_md_get_size_from_type(md_alg); 2323 if (md_size == 0) { 2324 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2325 } 2326 2327 if (mbedtls_oid_get_oid_by_md(md_alg, &oid, &oid_size) != 0) { 2328 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2329 } 2330 2331 if (hashlen != md_size) { 2332 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2333 } 2334 2335 /* Double-check that 8 + hashlen + oid_size can be used as a 2336 * 1-byte ASN.1 length encoding and that there's no overflow. */ 2337 if (8 + hashlen + oid_size >= 0x80 || 2338 10 + hashlen < hashlen || 2339 10 + hashlen + oid_size < 10 + hashlen) { 2340 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2341 } 2342 2343 /* 2344 * Static bounds check: 2345 * - Need 10 bytes for five tag-length pairs. 2346 * (Insist on 1-byte length encodings to protect against variants of 2347 * Bleichenbacher's forgery attack against lax PKCS#1v1.5 verification) 2348 * - Need hashlen bytes for hash 2349 * - Need oid_size bytes for hash alg OID. 2350 */ 2351 if (nb_pad < 10 + hashlen + oid_size) { 2352 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2353 } 2354 nb_pad -= 10 + hashlen + oid_size; 2355 } else { 2356 if (nb_pad < hashlen) { 2357 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2358 } 2359 2360 nb_pad -= hashlen; 2361 } 2362 2363 /* Need space for signature header and padding delimiter (3 bytes), 2364 * and 8 bytes for the minimal padding */ 2365 if (nb_pad < 3 + 8) { 2366 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2367 } 2368 nb_pad -= 3; 2369 2370 /* Now nb_pad is the amount of memory to be filled 2371 * with padding, and at least 8 bytes long. */ 2372 2373 /* Write signature header and padding */ 2374 *p++ = 0; 2375 *p++ = MBEDTLS_RSA_SIGN; 2376 memset(p, 0xFF, nb_pad); 2377 p += nb_pad; 2378 *p++ = 0; 2379 2380 /* Are we signing raw data? */ 2381 if (md_alg == MBEDTLS_MD_NONE) { 2382 memcpy(p, hash, hashlen); 2383 return 0; 2384 } 2385 2386 /* Signing hashed data, add corresponding ASN.1 structure 2387 * 2388 * DigestInfo ::= SEQUENCE { 2389 * digestAlgorithm DigestAlgorithmIdentifier, 2390 * digest Digest } 2391 * DigestAlgorithmIdentifier ::= AlgorithmIdentifier 2392 * Digest ::= OCTET STRING 2393 * 2394 * Schematic: 2395 * TAG-SEQ + LEN [ TAG-SEQ + LEN [ TAG-OID + LEN [ OID ] 2396 * TAG-NULL + LEN [ NULL ] ] 2397 * TAG-OCTET + LEN [ HASH ] ] 2398 */ 2399 *p++ = MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED; 2400 *p++ = (unsigned char) (0x08 + oid_size + hashlen); 2401 *p++ = MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED; 2402 *p++ = (unsigned char) (0x04 + oid_size); 2403 *p++ = MBEDTLS_ASN1_OID; 2404 *p++ = (unsigned char) oid_size; 2405 memcpy(p, oid, oid_size); 2406 p += oid_size; 2407 *p++ = MBEDTLS_ASN1_NULL; 2408 *p++ = 0x00; 2409 *p++ = MBEDTLS_ASN1_OCTET_STRING; 2410 *p++ = (unsigned char) hashlen; 2411 memcpy(p, hash, hashlen); 2412 p += hashlen; 2413 2414 /* Just a sanity-check, should be automatic 2415 * after the initial bounds check. */ 2416 if (p != dst + dst_len) { 2417 mbedtls_platform_zeroize(dst, dst_len); 2418 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2419 } 2420 2421 return 0; 2422} 2423 2424/* 2425 * Do an RSA operation to sign the message digest 2426 */ 2427int mbedtls_rsa_rsassa_pkcs1_v15_sign(mbedtls_rsa_context *ctx, 2428 int (*f_rng)(void *, unsigned char *, size_t), 2429 void *p_rng, 2430 mbedtls_md_type_t md_alg, 2431 unsigned int hashlen, 2432 const unsigned char *hash, 2433 unsigned char *sig) 2434{ 2435 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 2436 unsigned char *sig_try = NULL, *verif = NULL; 2437 2438 if ((md_alg != MBEDTLS_MD_NONE || hashlen != 0) && hash == NULL) { 2439 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2440 } 2441 2442 if (ctx->padding != MBEDTLS_RSA_PKCS_V15) { 2443 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2444 } 2445 2446 /* 2447 * Prepare PKCS1-v1.5 encoding (padding and hash identifier) 2448 */ 2449 2450 if ((ret = rsa_rsassa_pkcs1_v15_encode(md_alg, hashlen, hash, 2451 ctx->len, sig)) != 0) { 2452 return ret; 2453 } 2454 2455 /* Private key operation 2456 * 2457 * In order to prevent Lenstra's attack, make the signature in a 2458 * temporary buffer and check it before returning it. 2459 */ 2460 2461 sig_try = mbedtls_calloc(1, ctx->len); 2462 if (sig_try == NULL) { 2463 return MBEDTLS_ERR_MPI_ALLOC_FAILED; 2464 } 2465 2466 verif = mbedtls_calloc(1, ctx->len); 2467 if (verif == NULL) { 2468 mbedtls_free(sig_try); 2469 return MBEDTLS_ERR_MPI_ALLOC_FAILED; 2470 } 2471 2472 MBEDTLS_MPI_CHK(mbedtls_rsa_private(ctx, f_rng, p_rng, sig, sig_try)); 2473 MBEDTLS_MPI_CHK(mbedtls_rsa_public(ctx, sig_try, verif)); 2474 2475 if (mbedtls_ct_memcmp(verif, sig, ctx->len) != 0) { 2476 ret = MBEDTLS_ERR_RSA_PRIVATE_FAILED; 2477 goto cleanup; 2478 } 2479 2480 memcpy(sig, sig_try, ctx->len); 2481 2482cleanup: 2483 mbedtls_zeroize_and_free(sig_try, ctx->len); 2484 mbedtls_zeroize_and_free(verif, ctx->len); 2485 2486 if (ret != 0) { 2487 memset(sig, '!', ctx->len); 2488 } 2489 return ret; 2490} 2491#endif /* MBEDTLS_PKCS1_V15 */ 2492 2493/* 2494 * Do an RSA operation to sign the message digest 2495 */ 2496int mbedtls_rsa_pkcs1_sign(mbedtls_rsa_context *ctx, 2497 int (*f_rng)(void *, unsigned char *, size_t), 2498 void *p_rng, 2499 mbedtls_md_type_t md_alg, 2500 unsigned int hashlen, 2501 const unsigned char *hash, 2502 unsigned char *sig) 2503{ 2504 if ((md_alg != MBEDTLS_MD_NONE || hashlen != 0) && hash == NULL) { 2505 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2506 } 2507 2508 switch (ctx->padding) { 2509#if defined(MBEDTLS_PKCS1_V15) 2510 case MBEDTLS_RSA_PKCS_V15: 2511 return mbedtls_rsa_rsassa_pkcs1_v15_sign(ctx, f_rng, p_rng, 2512 md_alg, hashlen, hash, sig); 2513#endif 2514 2515#if defined(MBEDTLS_PKCS1_V21) 2516 case MBEDTLS_RSA_PKCS_V21: 2517 return mbedtls_rsa_rsassa_pss_sign(ctx, f_rng, p_rng, md_alg, 2518 hashlen, hash, sig); 2519#endif 2520 2521 default: 2522 return MBEDTLS_ERR_RSA_INVALID_PADDING; 2523 } 2524} 2525 2526#if defined(MBEDTLS_PKCS1_V21) 2527/* 2528 * Implementation of the PKCS#1 v2.1 RSASSA-PSS-VERIFY function 2529 */ 2530int mbedtls_rsa_rsassa_pss_verify_ext(mbedtls_rsa_context *ctx, 2531 mbedtls_md_type_t md_alg, 2532 unsigned int hashlen, 2533 const unsigned char *hash, 2534 mbedtls_md_type_t mgf1_hash_id, 2535 int expected_salt_len, 2536 const unsigned char *sig) 2537{ 2538 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 2539 size_t siglen; 2540 unsigned char *p; 2541 unsigned char *hash_start; 2542 unsigned char result[MBEDTLS_MD_MAX_SIZE]; 2543 unsigned int hlen; 2544 size_t observed_salt_len, msb; 2545 unsigned char buf[MBEDTLS_MPI_MAX_SIZE] = { 0 }; 2546 2547 if ((md_alg != MBEDTLS_MD_NONE || hashlen != 0) && hash == NULL) { 2548 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2549 } 2550 2551 siglen = ctx->len; 2552 2553 if (siglen < 16 || siglen > sizeof(buf)) { 2554 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2555 } 2556 2557 ret = mbedtls_rsa_public(ctx, sig, buf); 2558 2559 if (ret != 0) { 2560 return ret; 2561 } 2562 2563 p = buf; 2564 2565 if (buf[siglen - 1] != 0xBC) { 2566 return MBEDTLS_ERR_RSA_INVALID_PADDING; 2567 } 2568 2569 if (md_alg != MBEDTLS_MD_NONE) { 2570 /* Gather length of hash to sign */ 2571 size_t exp_hashlen = mbedtls_md_get_size_from_type(md_alg); 2572 if (exp_hashlen == 0) { 2573 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2574 } 2575 2576 if (hashlen != exp_hashlen) { 2577 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2578 } 2579 } 2580 2581 hlen = mbedtls_md_get_size_from_type(mgf1_hash_id); 2582 if (hlen == 0) { 2583 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2584 } 2585 2586 /* 2587 * Note: EMSA-PSS verification is over the length of N - 1 bits 2588 */ 2589 msb = mbedtls_mpi_bitlen(&ctx->N) - 1; 2590 2591 if (buf[0] >> (8 - siglen * 8 + msb)) { 2592 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2593 } 2594 2595 /* Compensate for boundary condition when applying mask */ 2596 if (msb % 8 == 0) { 2597 p++; 2598 siglen -= 1; 2599 } 2600 2601 if (siglen < hlen + 2) { 2602 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2603 } 2604 hash_start = p + siglen - hlen - 1; 2605 2606 ret = mgf_mask(p, siglen - hlen - 1, hash_start, hlen, mgf1_hash_id); 2607 if (ret != 0) { 2608 return ret; 2609 } 2610 2611 buf[0] &= 0xFF >> (siglen * 8 - msb); 2612 2613 while (p < hash_start - 1 && *p == 0) { 2614 p++; 2615 } 2616 2617 if (*p++ != 0x01) { 2618 return MBEDTLS_ERR_RSA_INVALID_PADDING; 2619 } 2620 2621 observed_salt_len = (size_t) (hash_start - p); 2622 2623 if (expected_salt_len != MBEDTLS_RSA_SALT_LEN_ANY && 2624 observed_salt_len != (size_t) expected_salt_len) { 2625 return MBEDTLS_ERR_RSA_INVALID_PADDING; 2626 } 2627 2628 /* 2629 * Generate H = Hash( M' ) 2630 */ 2631 ret = hash_mprime(hash, hashlen, p, observed_salt_len, 2632 result, mgf1_hash_id); 2633 if (ret != 0) { 2634 return ret; 2635 } 2636 2637 if (memcmp(hash_start, result, hlen) != 0) { 2638 return MBEDTLS_ERR_RSA_VERIFY_FAILED; 2639 } 2640 2641 return 0; 2642} 2643 2644/* 2645 * Simplified PKCS#1 v2.1 RSASSA-PSS-VERIFY function 2646 */ 2647int mbedtls_rsa_rsassa_pss_verify(mbedtls_rsa_context *ctx, 2648 mbedtls_md_type_t md_alg, 2649 unsigned int hashlen, 2650 const unsigned char *hash, 2651 const unsigned char *sig) 2652{ 2653 mbedtls_md_type_t mgf1_hash_id; 2654 if ((md_alg != MBEDTLS_MD_NONE || hashlen != 0) && hash == NULL) { 2655 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2656 } 2657 2658 mgf1_hash_id = (ctx->hash_id != MBEDTLS_MD_NONE) 2659 ? (mbedtls_md_type_t) ctx->hash_id 2660 : md_alg; 2661 2662 return mbedtls_rsa_rsassa_pss_verify_ext(ctx, 2663 md_alg, hashlen, hash, 2664 mgf1_hash_id, 2665 MBEDTLS_RSA_SALT_LEN_ANY, 2666 sig); 2667 2668} 2669#endif /* MBEDTLS_PKCS1_V21 */ 2670 2671#if defined(MBEDTLS_PKCS1_V15) 2672/* 2673 * Implementation of the PKCS#1 v2.1 RSASSA-PKCS1-v1_5-VERIFY function 2674 */ 2675int mbedtls_rsa_rsassa_pkcs1_v15_verify(mbedtls_rsa_context *ctx, 2676 mbedtls_md_type_t md_alg, 2677 unsigned int hashlen, 2678 const unsigned char *hash, 2679 const unsigned char *sig) 2680{ 2681 int ret = 0; 2682 size_t sig_len; 2683 unsigned char *encoded = NULL, *encoded_expected = NULL; 2684 2685 if ((md_alg != MBEDTLS_MD_NONE || hashlen != 0) && hash == NULL) { 2686 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2687 } 2688 2689 sig_len = ctx->len; 2690 2691 /* 2692 * Prepare expected PKCS1 v1.5 encoding of hash. 2693 */ 2694 2695 if ((encoded = mbedtls_calloc(1, sig_len)) == NULL || 2696 (encoded_expected = mbedtls_calloc(1, sig_len)) == NULL) { 2697 ret = MBEDTLS_ERR_MPI_ALLOC_FAILED; 2698 goto cleanup; 2699 } 2700 2701 if ((ret = rsa_rsassa_pkcs1_v15_encode(md_alg, hashlen, hash, sig_len, 2702 encoded_expected)) != 0) { 2703 goto cleanup; 2704 } 2705 2706 /* 2707 * Apply RSA primitive to get what should be PKCS1 encoded hash. 2708 */ 2709 2710 ret = mbedtls_rsa_public(ctx, sig, encoded); 2711 if (ret != 0) { 2712 goto cleanup; 2713 } 2714 2715 /* 2716 * Compare 2717 */ 2718 2719 if ((ret = mbedtls_ct_memcmp(encoded, encoded_expected, 2720 sig_len)) != 0) { 2721 ret = MBEDTLS_ERR_RSA_VERIFY_FAILED; 2722 goto cleanup; 2723 } 2724 2725cleanup: 2726 2727 if (encoded != NULL) { 2728 mbedtls_zeroize_and_free(encoded, sig_len); 2729 } 2730 2731 if (encoded_expected != NULL) { 2732 mbedtls_zeroize_and_free(encoded_expected, sig_len); 2733 } 2734 2735 return ret; 2736} 2737#endif /* MBEDTLS_PKCS1_V15 */ 2738 2739/* 2740 * Do an RSA operation and check the message digest 2741 */ 2742int mbedtls_rsa_pkcs1_verify(mbedtls_rsa_context *ctx, 2743 mbedtls_md_type_t md_alg, 2744 unsigned int hashlen, 2745 const unsigned char *hash, 2746 const unsigned char *sig) 2747{ 2748 if ((md_alg != MBEDTLS_MD_NONE || hashlen != 0) && hash == NULL) { 2749 return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; 2750 } 2751 2752 switch (ctx->padding) { 2753#if defined(MBEDTLS_PKCS1_V15) 2754 case MBEDTLS_RSA_PKCS_V15: 2755 return mbedtls_rsa_rsassa_pkcs1_v15_verify(ctx, md_alg, 2756 hashlen, hash, sig); 2757#endif 2758 2759#if defined(MBEDTLS_PKCS1_V21) 2760 case MBEDTLS_RSA_PKCS_V21: 2761 return mbedtls_rsa_rsassa_pss_verify(ctx, md_alg, 2762 hashlen, hash, sig); 2763#endif 2764 2765 default: 2766 return MBEDTLS_ERR_RSA_INVALID_PADDING; 2767 } 2768} 2769 2770/* 2771 * Copy the components of an RSA key 2772 */ 2773int mbedtls_rsa_copy(mbedtls_rsa_context *dst, const mbedtls_rsa_context *src) 2774{ 2775 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 2776 2777 dst->len = src->len; 2778 2779 MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->N, &src->N)); 2780 MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->E, &src->E)); 2781 2782 MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->D, &src->D)); 2783 MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->P, &src->P)); 2784 MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->Q, &src->Q)); 2785 2786#if !defined(MBEDTLS_RSA_NO_CRT) 2787 MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->DP, &src->DP)); 2788 MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->DQ, &src->DQ)); 2789 MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->QP, &src->QP)); 2790 MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->RP, &src->RP)); 2791 MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->RQ, &src->RQ)); 2792#endif 2793 2794 MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->RN, &src->RN)); 2795 2796 MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->Vi, &src->Vi)); 2797 MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&dst->Vf, &src->Vf)); 2798 2799 dst->padding = src->padding; 2800 dst->hash_id = src->hash_id; 2801 2802cleanup: 2803 if (ret != 0) { 2804 mbedtls_rsa_free(dst); 2805 } 2806 2807 return ret; 2808} 2809 2810/* 2811 * Free the components of an RSA key 2812 */ 2813void mbedtls_rsa_free(mbedtls_rsa_context *ctx) 2814{ 2815 if (ctx == NULL) { 2816 return; 2817 } 2818 2819 mbedtls_mpi_free(&ctx->Vi); 2820 mbedtls_mpi_free(&ctx->Vf); 2821 mbedtls_mpi_free(&ctx->RN); 2822 mbedtls_mpi_free(&ctx->D); 2823 mbedtls_mpi_free(&ctx->Q); 2824 mbedtls_mpi_free(&ctx->P); 2825 mbedtls_mpi_free(&ctx->E); 2826 mbedtls_mpi_free(&ctx->N); 2827 2828#if !defined(MBEDTLS_RSA_NO_CRT) 2829 mbedtls_mpi_free(&ctx->RQ); 2830 mbedtls_mpi_free(&ctx->RP); 2831 mbedtls_mpi_free(&ctx->QP); 2832 mbedtls_mpi_free(&ctx->DQ); 2833 mbedtls_mpi_free(&ctx->DP); 2834#endif /* MBEDTLS_RSA_NO_CRT */ 2835 2836#if defined(MBEDTLS_THREADING_C) 2837 /* Free the mutex, but only if it hasn't been freed already. */ 2838 if (ctx->ver != 0) { 2839 mbedtls_mutex_free(&ctx->mutex); 2840 ctx->ver = 0; 2841 } 2842#endif 2843} 2844 2845#endif /* !MBEDTLS_RSA_ALT */ 2846 2847#if defined(MBEDTLS_SELF_TEST) 2848 2849 2850/* 2851 * Example RSA-1024 keypair, for test purposes 2852 */ 2853#define KEY_LEN 128 2854 2855#define RSA_N "9292758453063D803DD603D5E777D788" \ 2856 "8ED1D5BF35786190FA2F23EBC0848AEA" \ 2857 "DDA92CA6C3D80B32C4D109BE0F36D6AE" \ 2858 "7130B9CED7ACDF54CFC7555AC14EEBAB" \ 2859 "93A89813FBF3C4F8066D2D800F7C38A8" \ 2860 "1AE31942917403FF4946B0A83D3D3E05" \ 2861 "EE57C6F5F5606FB5D4BC6CD34EE0801A" \ 2862 "5E94BB77B07507233A0BC7BAC8F90F79" 2863 2864#define RSA_E "10001" 2865 2866#define RSA_D "24BF6185468786FDD303083D25E64EFC" \ 2867 "66CA472BC44D253102F8B4A9D3BFA750" \ 2868 "91386C0077937FE33FA3252D28855837" \ 2869 "AE1B484A8A9A45F7EE8C0C634F99E8CD" \ 2870 "DF79C5CE07EE72C7F123142198164234" \ 2871 "CABB724CF78B8173B9F880FC86322407" \ 2872 "AF1FEDFDDE2BEB674CA15F3E81A1521E" \ 2873 "071513A1E85B5DFA031F21ECAE91A34D" 2874 2875#define RSA_P "C36D0EB7FCD285223CFB5AABA5BDA3D8" \ 2876 "2C01CAD19EA484A87EA4377637E75500" \ 2877 "FCB2005C5C7DD6EC4AC023CDA285D796" \ 2878 "C3D9E75E1EFC42488BB4F1D13AC30A57" 2879 2880#define RSA_Q "C000DF51A7C77AE8D7C7370C1FF55B69" \ 2881 "E211C2B9E5DB1ED0BF61D0D9899620F4" \ 2882 "910E4168387E3C30AA1E00C339A79508" \ 2883 "8452DD96A9A5EA5D9DCA68DA636032AF" 2884 2885#define PT_LEN 24 2886#define RSA_PT "\xAA\xBB\xCC\x03\x02\x01\x00\xFF\xFF\xFF\xFF\xFF" \ 2887 "\x11\x22\x33\x0A\x0B\x0C\xCC\xDD\xDD\xDD\xDD\xDD" 2888 2889#if defined(MBEDTLS_PKCS1_V15) 2890static int myrand(void *rng_state, unsigned char *output, size_t len) 2891{ 2892#if !defined(__OpenBSD__) && !defined(__NetBSD__) 2893 size_t i; 2894 2895 if (rng_state != NULL) { 2896 rng_state = NULL; 2897 } 2898 2899 for (i = 0; i < len; ++i) { 2900 output[i] = rand(); 2901 } 2902#else 2903 if (rng_state != NULL) { 2904 rng_state = NULL; 2905 } 2906 2907 arc4random_buf(output, len); 2908#endif /* !OpenBSD && !NetBSD */ 2909 2910 return 0; 2911} 2912#endif /* MBEDTLS_PKCS1_V15 */ 2913 2914/* 2915 * Checkup routine 2916 */ 2917int mbedtls_rsa_self_test(int verbose) 2918{ 2919 int ret = 0; 2920#if defined(MBEDTLS_PKCS1_V15) 2921 size_t len; 2922 mbedtls_rsa_context rsa; 2923 unsigned char rsa_plaintext[PT_LEN]; 2924 unsigned char rsa_decrypted[PT_LEN]; 2925 unsigned char rsa_ciphertext[KEY_LEN]; 2926#if defined(MBEDTLS_MD_CAN_SHA1) 2927 unsigned char sha1sum[20]; 2928#endif 2929 2930 mbedtls_mpi K; 2931 2932 mbedtls_mpi_init(&K); 2933 mbedtls_rsa_init(&rsa); 2934 2935 MBEDTLS_MPI_CHK(mbedtls_mpi_read_string(&K, 16, RSA_N)); 2936 MBEDTLS_MPI_CHK(mbedtls_rsa_import(&rsa, &K, NULL, NULL, NULL, NULL)); 2937 MBEDTLS_MPI_CHK(mbedtls_mpi_read_string(&K, 16, RSA_P)); 2938 MBEDTLS_MPI_CHK(mbedtls_rsa_import(&rsa, NULL, &K, NULL, NULL, NULL)); 2939 MBEDTLS_MPI_CHK(mbedtls_mpi_read_string(&K, 16, RSA_Q)); 2940 MBEDTLS_MPI_CHK(mbedtls_rsa_import(&rsa, NULL, NULL, &K, NULL, NULL)); 2941 MBEDTLS_MPI_CHK(mbedtls_mpi_read_string(&K, 16, RSA_D)); 2942 MBEDTLS_MPI_CHK(mbedtls_rsa_import(&rsa, NULL, NULL, NULL, &K, NULL)); 2943 MBEDTLS_MPI_CHK(mbedtls_mpi_read_string(&K, 16, RSA_E)); 2944 MBEDTLS_MPI_CHK(mbedtls_rsa_import(&rsa, NULL, NULL, NULL, NULL, &K)); 2945 2946 MBEDTLS_MPI_CHK(mbedtls_rsa_complete(&rsa)); 2947 2948 if (verbose != 0) { 2949 mbedtls_printf(" RSA key validation: "); 2950 } 2951 2952 if (mbedtls_rsa_check_pubkey(&rsa) != 0 || 2953 mbedtls_rsa_check_privkey(&rsa) != 0) { 2954 if (verbose != 0) { 2955 mbedtls_printf("failed\n"); 2956 } 2957 2958 ret = 1; 2959 goto cleanup; 2960 } 2961 2962 if (verbose != 0) { 2963 mbedtls_printf("passed\n PKCS#1 encryption : "); 2964 } 2965 2966 memcpy(rsa_plaintext, RSA_PT, PT_LEN); 2967 2968 if (mbedtls_rsa_pkcs1_encrypt(&rsa, myrand, NULL, 2969 PT_LEN, rsa_plaintext, 2970 rsa_ciphertext) != 0) { 2971 if (verbose != 0) { 2972 mbedtls_printf("failed\n"); 2973 } 2974 2975 ret = 1; 2976 goto cleanup; 2977 } 2978 2979 if (verbose != 0) { 2980 mbedtls_printf("passed\n PKCS#1 decryption : "); 2981 } 2982 2983 if (mbedtls_rsa_pkcs1_decrypt(&rsa, myrand, NULL, 2984 &len, rsa_ciphertext, rsa_decrypted, 2985 sizeof(rsa_decrypted)) != 0) { 2986 if (verbose != 0) { 2987 mbedtls_printf("failed\n"); 2988 } 2989 2990 ret = 1; 2991 goto cleanup; 2992 } 2993 2994 if (memcmp(rsa_decrypted, rsa_plaintext, len) != 0) { 2995 if (verbose != 0) { 2996 mbedtls_printf("failed\n"); 2997 } 2998 2999 ret = 1; 3000 goto cleanup; 3001 } 3002 3003 if (verbose != 0) { 3004 mbedtls_printf("passed\n"); 3005 } 3006 3007#if defined(MBEDTLS_MD_CAN_SHA1) 3008 if (verbose != 0) { 3009 mbedtls_printf(" PKCS#1 data sign : "); 3010 } 3011 3012 if (mbedtls_md(mbedtls_md_info_from_type(MBEDTLS_MD_SHA1), 3013 rsa_plaintext, PT_LEN, sha1sum) != 0) { 3014 if (verbose != 0) { 3015 mbedtls_printf("failed\n"); 3016 } 3017 3018 return 1; 3019 } 3020 3021 if (mbedtls_rsa_pkcs1_sign(&rsa, myrand, NULL, 3022 MBEDTLS_MD_SHA1, 20, 3023 sha1sum, rsa_ciphertext) != 0) { 3024 if (verbose != 0) { 3025 mbedtls_printf("failed\n"); 3026 } 3027 3028 ret = 1; 3029 goto cleanup; 3030 } 3031 3032 if (verbose != 0) { 3033 mbedtls_printf("passed\n PKCS#1 sig. verify: "); 3034 } 3035 3036 if (mbedtls_rsa_pkcs1_verify(&rsa, MBEDTLS_MD_SHA1, 20, 3037 sha1sum, rsa_ciphertext) != 0) { 3038 if (verbose != 0) { 3039 mbedtls_printf("failed\n"); 3040 } 3041 3042 ret = 1; 3043 goto cleanup; 3044 } 3045 3046 if (verbose != 0) { 3047 mbedtls_printf("passed\n"); 3048 } 3049#endif /* MBEDTLS_MD_CAN_SHA1 */ 3050 3051 if (verbose != 0) { 3052 mbedtls_printf("\n"); 3053 } 3054 3055cleanup: 3056 mbedtls_mpi_free(&K); 3057 mbedtls_rsa_free(&rsa); 3058#else /* MBEDTLS_PKCS1_V15 */ 3059 ((void) verbose); 3060#endif /* MBEDTLS_PKCS1_V15 */ 3061 return ret; 3062} 3063 3064#endif /* MBEDTLS_SELF_TEST */ 3065 3066#endif /* MBEDTLS_RSA_C */ 3067