1/* crypto/rsa/rsa_eay.c */ 2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 3 * All rights reserved. 4 * 5 * This package is an SSL implementation written 6 * by Eric Young (eay@cryptsoft.com). 7 * The implementation was written so as to conform with Netscapes SSL. 8 * 9 * This library is free for commercial and non-commercial use as long as 10 * the following conditions are aheared to. The following conditions 11 * apply to all code found in this distribution, be it the RC4, RSA, 12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 13 * included with this distribution is covered by the same copyright terms 14 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 15 * 16 * Copyright remains Eric Young's, and as such any Copyright notices in 17 * the code are not to be removed. 18 * If this package is used in a product, Eric Young should be given attribution 19 * as the author of the parts of the library used. 20 * This can be in the form of a textual message at program startup or 21 * in documentation (online or textual) provided with the package. 22 * 23 * Redistribution and use in source and binary forms, with or without 24 * modification, are permitted provided that the following conditions 25 * are met: 26 * 1. Redistributions of source code must retain the copyright 27 * notice, this list of conditions and the following disclaimer. 28 * 2. Redistributions in binary form must reproduce the above copyright 29 * notice, this list of conditions and the following disclaimer in the 30 * documentation and/or other materials provided with the distribution. 31 * 3. All advertising materials mentioning features or use of this software 32 * must display the following acknowledgement: 33 * "This product includes cryptographic software written by 34 * Eric Young (eay@cryptsoft.com)" 35 * The word 'cryptographic' can be left out if the rouines from the library 36 * being used are not cryptographic related :-). 37 * 4. If you include any Windows specific code (or a derivative thereof) from 38 * the apps directory (application code) you must include an acknowledgement: 39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 40 * 41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 51 * SUCH DAMAGE. 52 * 53 * The licence and distribution terms for any publically available version or 54 * derivative of this code cannot be changed. i.e. this code cannot simply be 55 * copied and put under another distribution licence 56 * [including the GNU Public Licence.] 57 */ 58/* ==================================================================== 59 * Copyright (c) 1998-2006 The OpenSSL Project. All rights reserved. 60 * 61 * Redistribution and use in source and binary forms, with or without 62 * modification, are permitted provided that the following conditions 63 * are met: 64 * 65 * 1. Redistributions of source code must retain the above copyright 66 * notice, this list of conditions and the following disclaimer. 67 * 68 * 2. Redistributions in binary form must reproduce the above copyright 69 * notice, this list of conditions and the following disclaimer in 70 * the documentation and/or other materials provided with the 71 * distribution. 72 * 73 * 3. All advertising materials mentioning features or use of this 74 * software must display the following acknowledgment: 75 * "This product includes software developed by the OpenSSL Project 76 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 77 * 78 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 79 * endorse or promote products derived from this software without 80 * prior written permission. For written permission, please contact 81 * openssl-core@openssl.org. 82 * 83 * 5. Products derived from this software may not be called "OpenSSL" 84 * nor may "OpenSSL" appear in their names without prior written 85 * permission of the OpenSSL Project. 86 * 87 * 6. Redistributions of any form whatsoever must retain the following 88 * acknowledgment: 89 * "This product includes software developed by the OpenSSL Project 90 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" 91 * 92 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 93 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 94 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 95 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 96 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 97 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 98 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 99 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 100 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 101 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 102 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 103 * OF THE POSSIBILITY OF SUCH DAMAGE. 104 * ==================================================================== 105 * 106 * This product includes cryptographic software written by Eric Young 107 * (eay@cryptsoft.com). This product includes software written by Tim 108 * Hudson (tjh@cryptsoft.com). 109 * 110 */ 111 112#include <stdio.h> 113#include "cryptlib.h" 114#include <openssl/bn.h> 115#include <openssl/rsa.h> 116#include <openssl/rand.h> 117 118#if !defined(RSA_NULL) && !defined(OPENSSL_FIPS) 119 120static int RSA_eay_public_encrypt(int flen, const unsigned char *from, 121 unsigned char *to, RSA *rsa,int padding); 122static int RSA_eay_private_encrypt(int flen, const unsigned char *from, 123 unsigned char *to, RSA *rsa,int padding); 124static int RSA_eay_public_decrypt(int flen, const unsigned char *from, 125 unsigned char *to, RSA *rsa,int padding); 126static int RSA_eay_private_decrypt(int flen, const unsigned char *from, 127 unsigned char *to, RSA *rsa,int padding); 128static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *i, RSA *rsa, BN_CTX *ctx); 129static int RSA_eay_init(RSA *rsa); 130static int RSA_eay_finish(RSA *rsa); 131static RSA_METHOD rsa_pkcs1_eay_meth={ 132 "Eric Young's PKCS#1 RSA", 133 RSA_eay_public_encrypt, 134 RSA_eay_public_decrypt, /* signature verification */ 135 RSA_eay_private_encrypt, /* signing */ 136 RSA_eay_private_decrypt, 137 RSA_eay_mod_exp, 138 BN_mod_exp_mont, /* XXX probably we should not use Montgomery if e == 3 */ 139 RSA_eay_init, 140 RSA_eay_finish, 141 0, /* flags */ 142 NULL, 143 0, /* rsa_sign */ 144 0, /* rsa_verify */ 145 NULL /* rsa_keygen */ 146 }; 147 148const RSA_METHOD *RSA_PKCS1_SSLeay(void) 149 { 150 return(&rsa_pkcs1_eay_meth); 151 } 152 153static int RSA_eay_public_encrypt(int flen, const unsigned char *from, 154 unsigned char *to, RSA *rsa, int padding) 155 { 156 BIGNUM *f,*ret; 157 int i,j,k,num=0,r= -1; 158 unsigned char *buf=NULL; 159 BN_CTX *ctx=NULL; 160 161 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) 162 { 163 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_MODULUS_TOO_LARGE); 164 return -1; 165 } 166 167 if (BN_ucmp(rsa->n, rsa->e) <= 0) 168 { 169 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE); 170 return -1; 171 } 172 173 /* for large moduli, enforce exponent limit */ 174 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) 175 { 176 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) 177 { 178 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE); 179 return -1; 180 } 181 } 182 183 if ((ctx=BN_CTX_new()) == NULL) goto err; 184 BN_CTX_start(ctx); 185 f = BN_CTX_get(ctx); 186 ret = BN_CTX_get(ctx); 187 num=BN_num_bytes(rsa->n); 188 buf = OPENSSL_malloc(num); 189 if (!f || !ret || !buf) 190 { 191 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,ERR_R_MALLOC_FAILURE); 192 goto err; 193 } 194 195 switch (padding) 196 { 197 case RSA_PKCS1_PADDING: 198 i=RSA_padding_add_PKCS1_type_2(buf,num,from,flen); 199 break; 200#ifndef OPENSSL_NO_SHA 201 case RSA_PKCS1_OAEP_PADDING: 202 i=RSA_padding_add_PKCS1_OAEP(buf,num,from,flen,NULL,0); 203 break; 204#endif 205 case RSA_SSLV23_PADDING: 206 i=RSA_padding_add_SSLv23(buf,num,from,flen); 207 break; 208 case RSA_NO_PADDING: 209 i=RSA_padding_add_none(buf,num,from,flen); 210 break; 211 default: 212 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE); 213 goto err; 214 } 215 if (i <= 0) goto err; 216 217 if (BN_bin2bn(buf,num,f) == NULL) goto err; 218 219 if (BN_ucmp(f, rsa->n) >= 0) 220 { 221 /* usually the padding functions would catch this */ 222 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS); 223 goto err; 224 } 225 226 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) 227 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx)) 228 goto err; 229 230 if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx, 231 rsa->_method_mod_n)) goto err; 232 233 /* put in leading 0 bytes if the number is less than the 234 * length of the modulus */ 235 j=BN_num_bytes(ret); 236 i=BN_bn2bin(ret,&(to[num-j])); 237 for (k=0; k<(num-i); k++) 238 to[k]=0; 239 240 r=num; 241err: 242 if (ctx != NULL) 243 { 244 BN_CTX_end(ctx); 245 BN_CTX_free(ctx); 246 } 247 if (buf != NULL) 248 { 249 OPENSSL_cleanse(buf,num); 250 OPENSSL_free(buf); 251 } 252 return(r); 253 } 254 255static BN_BLINDING *rsa_get_blinding(RSA *rsa, int *local, BN_CTX *ctx) 256{ 257 BN_BLINDING *ret; 258 int got_write_lock = 0; 259 260 CRYPTO_r_lock(CRYPTO_LOCK_RSA); 261 262 if (rsa->blinding == NULL) 263 { 264 CRYPTO_r_unlock(CRYPTO_LOCK_RSA); 265 CRYPTO_w_lock(CRYPTO_LOCK_RSA); 266 got_write_lock = 1; 267 268 if (rsa->blinding == NULL) 269 rsa->blinding = RSA_setup_blinding(rsa, ctx); 270 } 271 272 ret = rsa->blinding; 273 if (ret == NULL) 274 goto err; 275 276 if (BN_BLINDING_get_thread_id(ret) == CRYPTO_thread_id()) 277 { 278 /* rsa->blinding is ours! */ 279 280 *local = 1; 281 } 282 else 283 { 284 /* resort to rsa->mt_blinding instead */ 285 286 *local = 0; /* instructs rsa_blinding_convert(), rsa_blinding_invert() 287 * that the BN_BLINDING is shared, meaning that accesses 288 * require locks, and that the blinding factor must be 289 * stored outside the BN_BLINDING 290 */ 291 292 if (rsa->mt_blinding == NULL) 293 { 294 if (!got_write_lock) 295 { 296 CRYPTO_r_unlock(CRYPTO_LOCK_RSA); 297 CRYPTO_w_lock(CRYPTO_LOCK_RSA); 298 got_write_lock = 1; 299 } 300 301 if (rsa->mt_blinding == NULL) 302 rsa->mt_blinding = RSA_setup_blinding(rsa, ctx); 303 } 304 ret = rsa->mt_blinding; 305 } 306 307 err: 308 if (got_write_lock) 309 CRYPTO_w_unlock(CRYPTO_LOCK_RSA); 310 else 311 CRYPTO_r_unlock(CRYPTO_LOCK_RSA); 312 return ret; 313} 314 315static int rsa_blinding_convert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind, 316 BN_CTX *ctx) 317 { 318 if (unblind == NULL) 319 /* Local blinding: store the unblinding factor 320 * in BN_BLINDING. */ 321 return BN_BLINDING_convert_ex(f, NULL, b, ctx); 322 else 323 { 324 /* Shared blinding: store the unblinding factor 325 * outside BN_BLINDING. */ 326 int ret; 327 CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING); 328 ret = BN_BLINDING_convert_ex(f, unblind, b, ctx); 329 CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING); 330 return ret; 331 } 332 } 333 334static int rsa_blinding_invert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind, 335 BN_CTX *ctx) 336 { 337 /* For local blinding, unblind is set to NULL, and BN_BLINDING_invert_ex 338 * will use the unblinding factor stored in BN_BLINDING. 339 * If BN_BLINDING is shared between threads, unblind must be non-null: 340 * BN_BLINDING_invert_ex will then use the local unblinding factor, 341 * and will only read the modulus from BN_BLINDING. 342 * In both cases it's safe to access the blinding without a lock. 343 */ 344 return BN_BLINDING_invert_ex(f, unblind, b, ctx); 345 } 346 347/* signing */ 348static int RSA_eay_private_encrypt(int flen, const unsigned char *from, 349 unsigned char *to, RSA *rsa, int padding) 350 { 351 BIGNUM *f, *ret, *res; 352 int i,j,k,num=0,r= -1; 353 unsigned char *buf=NULL; 354 BN_CTX *ctx=NULL; 355 int local_blinding = 0; 356 /* Used only if the blinding structure is shared. A non-NULL unblind 357 * instructs rsa_blinding_convert() and rsa_blinding_invert() to store 358 * the unblinding factor outside the blinding structure. */ 359 BIGNUM *unblind = NULL; 360 BN_BLINDING *blinding = NULL; 361 362 if ((ctx=BN_CTX_new()) == NULL) goto err; 363 BN_CTX_start(ctx); 364 f = BN_CTX_get(ctx); 365 ret = BN_CTX_get(ctx); 366 num = BN_num_bytes(rsa->n); 367 buf = OPENSSL_malloc(num); 368 if(!f || !ret || !buf) 369 { 370 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE); 371 goto err; 372 } 373 374 switch (padding) 375 { 376 case RSA_PKCS1_PADDING: 377 i=RSA_padding_add_PKCS1_type_1(buf,num,from,flen); 378 break; 379 case RSA_X931_PADDING: 380 i=RSA_padding_add_X931(buf,num,from,flen); 381 break; 382 case RSA_NO_PADDING: 383 i=RSA_padding_add_none(buf,num,from,flen); 384 break; 385 case RSA_SSLV23_PADDING: 386 default: 387 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE); 388 goto err; 389 } 390 if (i <= 0) goto err; 391 392 if (BN_bin2bn(buf,num,f) == NULL) goto err; 393 394 if (BN_ucmp(f, rsa->n) >= 0) 395 { 396 /* usually the padding functions would catch this */ 397 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS); 398 goto err; 399 } 400 401 if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) 402 { 403 blinding = rsa_get_blinding(rsa, &local_blinding, ctx); 404 if (blinding == NULL) 405 { 406 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR); 407 goto err; 408 } 409 } 410 411 if (blinding != NULL) 412 { 413 if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) 414 { 415 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE); 416 goto err; 417 } 418 if (!rsa_blinding_convert(blinding, f, unblind, ctx)) 419 goto err; 420 } 421 422 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) || 423 ((rsa->p != NULL) && 424 (rsa->q != NULL) && 425 (rsa->dmp1 != NULL) && 426 (rsa->dmq1 != NULL) && 427 (rsa->iqmp != NULL)) ) 428 { 429 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err; 430 } 431 else 432 { 433 BIGNUM local_d; 434 BIGNUM *d = NULL; 435 436 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 437 { 438 BN_init(&local_d); 439 d = &local_d; 440 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); 441 } 442 else 443 d= rsa->d; 444 445 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) 446 if(!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx)) 447 goto err; 448 449 if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx, 450 rsa->_method_mod_n)) goto err; 451 } 452 453 if (blinding) 454 if (!rsa_blinding_invert(blinding, ret, unblind, ctx)) 455 goto err; 456 457 if (padding == RSA_X931_PADDING) 458 { 459 BN_sub(f, rsa->n, ret); 460 if (BN_cmp(ret, f)) 461 res = f; 462 else 463 res = ret; 464 } 465 else 466 res = ret; 467 468 /* put in leading 0 bytes if the number is less than the 469 * length of the modulus */ 470 j=BN_num_bytes(res); 471 i=BN_bn2bin(res,&(to[num-j])); 472 for (k=0; k<(num-i); k++) 473 to[k]=0; 474 475 r=num; 476err: 477 if (ctx != NULL) 478 { 479 BN_CTX_end(ctx); 480 BN_CTX_free(ctx); 481 } 482 if (buf != NULL) 483 { 484 OPENSSL_cleanse(buf,num); 485 OPENSSL_free(buf); 486 } 487 return(r); 488 } 489 490static int RSA_eay_private_decrypt(int flen, const unsigned char *from, 491 unsigned char *to, RSA *rsa, int padding) 492 { 493 BIGNUM *f, *ret; 494 int j,num=0,r= -1; 495 unsigned char *p; 496 unsigned char *buf=NULL; 497 BN_CTX *ctx=NULL; 498 int local_blinding = 0; 499 /* Used only if the blinding structure is shared. A non-NULL unblind 500 * instructs rsa_blinding_convert() and rsa_blinding_invert() to store 501 * the unblinding factor outside the blinding structure. */ 502 BIGNUM *unblind = NULL; 503 BN_BLINDING *blinding = NULL; 504 505 if((ctx = BN_CTX_new()) == NULL) goto err; 506 BN_CTX_start(ctx); 507 f = BN_CTX_get(ctx); 508 ret = BN_CTX_get(ctx); 509 num = BN_num_bytes(rsa->n); 510 buf = OPENSSL_malloc(num); 511 if(!f || !ret || !buf) 512 { 513 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE); 514 goto err; 515 } 516 517 /* This check was for equality but PGP does evil things 518 * and chops off the top '0' bytes */ 519 if (flen > num) 520 { 521 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN); 522 goto err; 523 } 524 525 /* make data into a big number */ 526 if (BN_bin2bn(from,(int)flen,f) == NULL) goto err; 527 528 if (BN_ucmp(f, rsa->n) >= 0) 529 { 530 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS); 531 goto err; 532 } 533 534 if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) 535 { 536 blinding = rsa_get_blinding(rsa, &local_blinding, ctx); 537 if (blinding == NULL) 538 { 539 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR); 540 goto err; 541 } 542 } 543 544 if (blinding != NULL) 545 { 546 if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) 547 { 548 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE); 549 goto err; 550 } 551 if (!rsa_blinding_convert(blinding, f, unblind, ctx)) 552 goto err; 553 } 554 555 /* do the decrypt */ 556 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) || 557 ((rsa->p != NULL) && 558 (rsa->q != NULL) && 559 (rsa->dmp1 != NULL) && 560 (rsa->dmq1 != NULL) && 561 (rsa->iqmp != NULL)) ) 562 { 563 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err; 564 } 565 else 566 { 567 BIGNUM local_d; 568 BIGNUM *d = NULL; 569 570 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 571 { 572 d = &local_d; 573 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); 574 } 575 else 576 d = rsa->d; 577 578 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) 579 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx)) 580 goto err; 581 if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx, 582 rsa->_method_mod_n)) 583 goto err; 584 } 585 586 if (blinding) 587 if (!rsa_blinding_invert(blinding, ret, unblind, ctx)) 588 goto err; 589 590 p=buf; 591 j=BN_bn2bin(ret,p); /* j is only used with no-padding mode */ 592 593 switch (padding) 594 { 595 case RSA_PKCS1_PADDING: 596 r=RSA_padding_check_PKCS1_type_2(to,num,buf,j,num); 597 break; 598#ifndef OPENSSL_NO_SHA 599 case RSA_PKCS1_OAEP_PADDING: 600 r=RSA_padding_check_PKCS1_OAEP(to,num,buf,j,num,NULL,0); 601 break; 602#endif 603 case RSA_SSLV23_PADDING: 604 r=RSA_padding_check_SSLv23(to,num,buf,j,num); 605 break; 606 case RSA_NO_PADDING: 607 r=RSA_padding_check_none(to,num,buf,j,num); 608 break; 609 default: 610 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE); 611 goto err; 612 } 613 if (r < 0) 614 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_PADDING_CHECK_FAILED); 615 616err: 617 if (ctx != NULL) 618 { 619 BN_CTX_end(ctx); 620 BN_CTX_free(ctx); 621 } 622 if (buf != NULL) 623 { 624 OPENSSL_cleanse(buf,num); 625 OPENSSL_free(buf); 626 } 627 return(r); 628 } 629 630/* signature verification */ 631static int RSA_eay_public_decrypt(int flen, const unsigned char *from, 632 unsigned char *to, RSA *rsa, int padding) 633 { 634 BIGNUM *f,*ret; 635 int i,num=0,r= -1; 636 unsigned char *p; 637 unsigned char *buf=NULL; 638 BN_CTX *ctx=NULL; 639 640 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) 641 { 642 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE); 643 return -1; 644 } 645 646 if (BN_ucmp(rsa->n, rsa->e) <= 0) 647 { 648 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE); 649 return -1; 650 } 651 652 /* for large moduli, enforce exponent limit */ 653 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) 654 { 655 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) 656 { 657 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE); 658 return -1; 659 } 660 } 661 662 if((ctx = BN_CTX_new()) == NULL) goto err; 663 BN_CTX_start(ctx); 664 f = BN_CTX_get(ctx); 665 ret = BN_CTX_get(ctx); 666 num=BN_num_bytes(rsa->n); 667 buf = OPENSSL_malloc(num); 668 if(!f || !ret || !buf) 669 { 670 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE); 671 goto err; 672 } 673 674 /* This check was for equality but PGP does evil things 675 * and chops off the top '0' bytes */ 676 if (flen > num) 677 { 678 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN); 679 goto err; 680 } 681 682 if (BN_bin2bn(from,flen,f) == NULL) goto err; 683 684 if (BN_ucmp(f, rsa->n) >= 0) 685 { 686 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS); 687 goto err; 688 } 689 690 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) 691 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx)) 692 goto err; 693 694 if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx, 695 rsa->_method_mod_n)) goto err; 696 697 if ((padding == RSA_X931_PADDING) && ((ret->d[0] & 0xf) != 12)) 698 if (!BN_sub(ret, rsa->n, ret)) goto err; 699 700 p=buf; 701 i=BN_bn2bin(ret,p); 702 703 switch (padding) 704 { 705 case RSA_PKCS1_PADDING: 706 r=RSA_padding_check_PKCS1_type_1(to,num,buf,i,num); 707 break; 708 case RSA_X931_PADDING: 709 r=RSA_padding_check_X931(to,num,buf,i,num); 710 break; 711 case RSA_NO_PADDING: 712 r=RSA_padding_check_none(to,num,buf,i,num); 713 break; 714 default: 715 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE); 716 goto err; 717 } 718 if (r < 0) 719 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_PADDING_CHECK_FAILED); 720 721err: 722 if (ctx != NULL) 723 { 724 BN_CTX_end(ctx); 725 BN_CTX_free(ctx); 726 } 727 if (buf != NULL) 728 { 729 OPENSSL_cleanse(buf,num); 730 OPENSSL_free(buf); 731 } 732 return(r); 733 } 734 735static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx) 736 { 737 BIGNUM *r1,*m1,*vrfy; 738 BIGNUM local_dmp1,local_dmq1,local_c,local_r1; 739 BIGNUM *dmp1,*dmq1,*c,*pr1; 740 int ret=0; 741 742 BN_CTX_start(ctx); 743 r1 = BN_CTX_get(ctx); 744 m1 = BN_CTX_get(ctx); 745 vrfy = BN_CTX_get(ctx); 746 747 { 748 BIGNUM local_p, local_q; 749 BIGNUM *p = NULL, *q = NULL; 750 751 /* Make sure BN_mod_inverse in Montgomery intialization uses the 752 * BN_FLG_CONSTTIME flag (unless RSA_FLAG_NO_CONSTTIME is set) 753 */ 754 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 755 { 756 BN_init(&local_p); 757 p = &local_p; 758 BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME); 759 760 BN_init(&local_q); 761 q = &local_q; 762 BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME); 763 } 764 else 765 { 766 p = rsa->p; 767 q = rsa->q; 768 } 769 770 if (rsa->flags & RSA_FLAG_CACHE_PRIVATE) 771 { 772 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_p, CRYPTO_LOCK_RSA, p, ctx)) 773 goto err; 774 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_q, CRYPTO_LOCK_RSA, q, ctx)) 775 goto err; 776 } 777 } 778 779 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) 780 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx)) 781 goto err; 782 783 /* compute I mod q */ 784 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 785 { 786 c = &local_c; 787 BN_with_flags(c, I, BN_FLG_CONSTTIME); 788 if (!BN_mod(r1,c,rsa->q,ctx)) goto err; 789 } 790 else 791 { 792 if (!BN_mod(r1,I,rsa->q,ctx)) goto err; 793 } 794 795 /* compute r1^dmq1 mod q */ 796 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 797 { 798 dmq1 = &local_dmq1; 799 BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME); 800 } 801 else 802 dmq1 = rsa->dmq1; 803 if (!rsa->meth->bn_mod_exp(m1,r1,dmq1,rsa->q,ctx, 804 rsa->_method_mod_q)) goto err; 805 806 /* compute I mod p */ 807 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 808 { 809 c = &local_c; 810 BN_with_flags(c, I, BN_FLG_CONSTTIME); 811 if (!BN_mod(r1,c,rsa->p,ctx)) goto err; 812 } 813 else 814 { 815 if (!BN_mod(r1,I,rsa->p,ctx)) goto err; 816 } 817 818 /* compute r1^dmp1 mod p */ 819 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 820 { 821 dmp1 = &local_dmp1; 822 BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME); 823 } 824 else 825 dmp1 = rsa->dmp1; 826 if (!rsa->meth->bn_mod_exp(r0,r1,dmp1,rsa->p,ctx, 827 rsa->_method_mod_p)) goto err; 828 829 if (!BN_sub(r0,r0,m1)) goto err; 830 /* This will help stop the size of r0 increasing, which does 831 * affect the multiply if it optimised for a power of 2 size */ 832 if (BN_is_negative(r0)) 833 if (!BN_add(r0,r0,rsa->p)) goto err; 834 835 if (!BN_mul(r1,r0,rsa->iqmp,ctx)) goto err; 836 837 /* Turn BN_FLG_CONSTTIME flag on before division operation */ 838 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 839 { 840 pr1 = &local_r1; 841 BN_with_flags(pr1, r1, BN_FLG_CONSTTIME); 842 } 843 else 844 pr1 = r1; 845 if (!BN_mod(r0,pr1,rsa->p,ctx)) goto err; 846 847 /* If p < q it is occasionally possible for the correction of 848 * adding 'p' if r0 is negative above to leave the result still 849 * negative. This can break the private key operations: the following 850 * second correction should *always* correct this rare occurrence. 851 * This will *never* happen with OpenSSL generated keys because 852 * they ensure p > q [steve] 853 */ 854 if (BN_is_negative(r0)) 855 if (!BN_add(r0,r0,rsa->p)) goto err; 856 if (!BN_mul(r1,r0,rsa->q,ctx)) goto err; 857 if (!BN_add(r0,r1,m1)) goto err; 858 859 if (rsa->e && rsa->n) 860 { 861 if (!rsa->meth->bn_mod_exp(vrfy,r0,rsa->e,rsa->n,ctx,rsa->_method_mod_n)) goto err; 862 /* If 'I' was greater than (or equal to) rsa->n, the operation 863 * will be equivalent to using 'I mod n'. However, the result of 864 * the verify will *always* be less than 'n' so we don't check 865 * for absolute equality, just congruency. */ 866 if (!BN_sub(vrfy, vrfy, I)) goto err; 867 if (!BN_mod(vrfy, vrfy, rsa->n, ctx)) goto err; 868 if (BN_is_negative(vrfy)) 869 if (!BN_add(vrfy, vrfy, rsa->n)) goto err; 870 if (!BN_is_zero(vrfy)) 871 { 872 /* 'I' and 'vrfy' aren't congruent mod n. Don't leak 873 * miscalculated CRT output, just do a raw (slower) 874 * mod_exp and return that instead. */ 875 876 BIGNUM local_d; 877 BIGNUM *d = NULL; 878 879 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 880 { 881 d = &local_d; 882 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); 883 } 884 else 885 d = rsa->d; 886 if (!rsa->meth->bn_mod_exp(r0,I,d,rsa->n,ctx, 887 rsa->_method_mod_n)) goto err; 888 } 889 } 890 ret=1; 891err: 892 BN_CTX_end(ctx); 893 return(ret); 894 } 895 896static int RSA_eay_init(RSA *rsa) 897 { 898 rsa->flags|=RSA_FLAG_CACHE_PUBLIC|RSA_FLAG_CACHE_PRIVATE; 899 return(1); 900 } 901 902static int RSA_eay_finish(RSA *rsa) 903 { 904 if (rsa->_method_mod_n != NULL) 905 BN_MONT_CTX_free(rsa->_method_mod_n); 906 if (rsa->_method_mod_p != NULL) 907 BN_MONT_CTX_free(rsa->_method_mod_p); 908 if (rsa->_method_mod_q != NULL) 909 BN_MONT_CTX_free(rsa->_method_mod_q); 910 return(1); 911 } 912 913#endif 914