1 /* crypto/rsa/rsa_eay.c */ 2 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com) 3 * All rights reserved. 4 * 5 * This package is an SSL implementation written 6 * by Eric Young (eay (at) 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 (at) 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 (at) 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 (at) 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 (at) 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 (at) cryptsoft.com). This product includes software written by Tim 108 * Hudson (tjh (at) 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) 119 120 static int RSA_eay_public_encrypt(int flen, const unsigned char *from, 121 unsigned char *to, RSA *rsa,int padding); 122 static int RSA_eay_private_encrypt(int flen, const unsigned char *from, 123 unsigned char *to, RSA *rsa,int padding); 124 static int RSA_eay_public_decrypt(int flen, const unsigned char *from, 125 unsigned char *to, RSA *rsa,int padding); 126 static int RSA_eay_private_decrypt(int flen, const unsigned char *from, 127 unsigned char *to, RSA *rsa,int padding); 128 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *i, RSA *rsa, BN_CTX *ctx); 129 static int RSA_eay_init(RSA *rsa); 130 static int RSA_eay_finish(RSA *rsa); 131 static 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 }; 147 148 const RSA_METHOD *RSA_PKCS1_SSLeay(void) 149 { 150 return(&rsa_pkcs1_eay_meth); 151 } 152 153 static 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; 241 err: 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 } 254 255 static 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 } 314 315 static int rsa_blinding_convert(BN_BLINDING *b, int local, BIGNUM *f, 316 BIGNUM *r, BN_CTX *ctx) 317 { 318 if (local) 319 return BN_BLINDING_convert_ex(f, NULL, b, ctx); 320 else 321 { 322 int ret; 323 CRYPTO_r_lock(CRYPTO_LOCK_RSA_BLINDING); 324 ret = BN_BLINDING_convert_ex(f, r, b, ctx); 325 CRYPTO_r_unlock(CRYPTO_LOCK_RSA_BLINDING); 326 return ret; 327 } 328 } 329 330 static int rsa_blinding_invert(BN_BLINDING *b, int local, BIGNUM *f, 331 BIGNUM *r, BN_CTX *ctx) 332 { 333 if (local) 334 return BN_BLINDING_invert_ex(f, NULL, b, ctx); 335 else 336 { 337 int ret; 338 CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING); 339 ret = BN_BLINDING_invert_ex(f, r, b, ctx); 340 CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING); 341 return ret; 342 } 343 } 344 345 /* signing */ 346 static int RSA_eay_private_encrypt(int flen, const unsigned char *from, 347 unsigned char *to, RSA *rsa, int padding) 348 { 349 BIGNUM *f, *ret, *br, *res; 350 int i,j,k,num=0,r= -1; 351 unsigned char *buf=NULL; 352 BN_CTX *ctx=NULL; 353 int local_blinding = 0; 354 BN_BLINDING *blinding = NULL; 355 356 if ((ctx=BN_CTX_new()) == NULL) goto err; 357 BN_CTX_start(ctx); 358 f = BN_CTX_get(ctx); 359 br = BN_CTX_get(ctx); 360 ret = BN_CTX_get(ctx); 361 num = BN_num_bytes(rsa->n); 362 buf = OPENSSL_malloc(num); 363 if(!f || !ret || !buf) 364 { 365 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE); 366 goto err; 367 } 368 369 switch (padding) 370 { 371 case RSA_PKCS1_PADDING: 372 i=RSA_padding_add_PKCS1_type_1(buf,num,from,flen); 373 break; 374 case RSA_X931_PADDING: 375 i=RSA_padding_add_X931(buf,num,from,flen); 376 break; 377 case RSA_NO_PADDING: 378 i=RSA_padding_add_none(buf,num,from,flen); 379 break; 380 case RSA_SSLV23_PADDING: 381 default: 382 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE); 383 goto err; 384 } 385 if (i <= 0) goto err; 386 387 if (BN_bin2bn(buf,num,f) == NULL) goto err; 388 389 if (BN_ucmp(f, rsa->n) >= 0) 390 { 391 /* usually the padding functions would catch this */ 392 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS); 393 goto err; 394 } 395 396 if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) 397 { 398 blinding = rsa_get_blinding(rsa, &local_blinding, ctx); 399 if (blinding == NULL) 400 { 401 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR); 402 goto err; 403 } 404 } 405 406 if (blinding != NULL) 407 if (!rsa_blinding_convert(blinding, local_blinding, f, br, ctx)) 408 goto err; 409 410 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) || 411 ((rsa->p != NULL) && 412 (rsa->q != NULL) && 413 (rsa->dmp1 != NULL) && 414 (rsa->dmq1 != NULL) && 415 (rsa->iqmp != NULL)) ) 416 { 417 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err; 418 } 419 else 420 { 421 BIGNUM local_d; 422 BIGNUM *d = NULL; 423 424 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 425 { 426 BN_init(&local_d); 427 d = &local_d; 428 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); 429 } 430 else 431 d= rsa->d; 432 433 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) 434 if(!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx)) 435 goto err; 436 437 if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx, 438 rsa->_method_mod_n)) goto err; 439 } 440 441 if (blinding) 442 if (!rsa_blinding_invert(blinding, local_blinding, ret, br, ctx)) 443 goto err; 444 445 if (padding == RSA_X931_PADDING) 446 { 447 BN_sub(f, rsa->n, ret); 448 if (BN_cmp(ret, f)) 449 res = f; 450 else 451 res = ret; 452 } 453 else 454 res = ret; 455 456 /* put in leading 0 bytes if the number is less than the 457 * length of the modulus */ 458 j=BN_num_bytes(res); 459 i=BN_bn2bin(res,&(to[num-j])); 460 for (k=0; k<(num-i); k++) 461 to[k]=0; 462 463 r=num; 464 err: 465 if (ctx != NULL) 466 { 467 BN_CTX_end(ctx); 468 BN_CTX_free(ctx); 469 } 470 if (buf != NULL) 471 { 472 OPENSSL_cleanse(buf,num); 473 OPENSSL_free(buf); 474 } 475 return(r); 476 } 477 478 static int RSA_eay_private_decrypt(int flen, const unsigned char *from, 479 unsigned char *to, RSA *rsa, int padding) 480 { 481 BIGNUM *f, *ret, *br; 482 int j,num=0,r= -1; 483 unsigned char *p; 484 unsigned char *buf=NULL; 485 BN_CTX *ctx=NULL; 486 int local_blinding = 0; 487 BN_BLINDING *blinding = NULL; 488 489 if((ctx = BN_CTX_new()) == NULL) goto err; 490 BN_CTX_start(ctx); 491 f = BN_CTX_get(ctx); 492 br = BN_CTX_get(ctx); 493 ret = BN_CTX_get(ctx); 494 num = BN_num_bytes(rsa->n); 495 buf = OPENSSL_malloc(num); 496 if(!f || !ret || !buf) 497 { 498 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE); 499 goto err; 500 } 501 502 /* This check was for equality but PGP does evil things 503 * and chops off the top '0' bytes */ 504 if (flen > num) 505 { 506 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN); 507 goto err; 508 } 509 510 /* make data into a big number */ 511 if (BN_bin2bn(from,(int)flen,f) == NULL) goto err; 512 513 if (BN_ucmp(f, rsa->n) >= 0) 514 { 515 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS); 516 goto err; 517 } 518 519 if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) 520 { 521 blinding = rsa_get_blinding(rsa, &local_blinding, ctx); 522 if (blinding == NULL) 523 { 524 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR); 525 goto err; 526 } 527 } 528 529 if (blinding != NULL) 530 if (!rsa_blinding_convert(blinding, local_blinding, f, br, ctx)) 531 goto err; 532 533 /* do the decrypt */ 534 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) || 535 ((rsa->p != NULL) && 536 (rsa->q != NULL) && 537 (rsa->dmp1 != NULL) && 538 (rsa->dmq1 != NULL) && 539 (rsa->iqmp != NULL)) ) 540 { 541 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err; 542 } 543 else 544 { 545 BIGNUM local_d; 546 BIGNUM *d = NULL; 547 548 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 549 { 550 d = &local_d; 551 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); 552 } 553 else 554 d = rsa->d; 555 556 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) 557 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx)) 558 goto err; 559 if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx, 560 rsa->_method_mod_n)) 561 goto err; 562 } 563 564 if (blinding) 565 if (!rsa_blinding_invert(blinding, local_blinding, ret, br, ctx)) 566 goto err; 567 568 p=buf; 569 j=BN_bn2bin(ret,p); /* j is only used with no-padding mode */ 570 571 switch (padding) 572 { 573 case RSA_PKCS1_PADDING: 574 r=RSA_padding_check_PKCS1_type_2(to,num,buf,j,num); 575 break; 576 #ifndef OPENSSL_NO_SHA 577 case RSA_PKCS1_OAEP_PADDING: 578 r=RSA_padding_check_PKCS1_OAEP(to,num,buf,j,num,NULL,0); 579 break; 580 #endif 581 case RSA_SSLV23_PADDING: 582 r=RSA_padding_check_SSLv23(to,num,buf,j,num); 583 break; 584 case RSA_NO_PADDING: 585 r=RSA_padding_check_none(to,num,buf,j,num); 586 break; 587 default: 588 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE); 589 goto err; 590 } 591 if (r < 0) 592 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_PADDING_CHECK_FAILED); 593 594 err: 595 if (ctx != NULL) 596 { 597 BN_CTX_end(ctx); 598 BN_CTX_free(ctx); 599 } 600 if (buf != NULL) 601 { 602 OPENSSL_cleanse(buf,num); 603 OPENSSL_free(buf); 604 } 605 return(r); 606 } 607 608 /* signature verification */ 609 static int RSA_eay_public_decrypt(int flen, const unsigned char *from, 610 unsigned char *to, RSA *rsa, int padding) 611 { 612 BIGNUM *f,*ret; 613 int i,num=0,r= -1; 614 unsigned char *p; 615 unsigned char *buf=NULL; 616 BN_CTX *ctx=NULL; 617 618 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) 619 { 620 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE); 621 return -1; 622 } 623 624 if (BN_ucmp(rsa->n, rsa->e) <= 0) 625 { 626 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE); 627 return -1; 628 } 629 630 /* for large moduli, enforce exponent limit */ 631 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) 632 { 633 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) 634 { 635 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE); 636 return -1; 637 } 638 } 639 640 if((ctx = BN_CTX_new()) == NULL) goto err; 641 BN_CTX_start(ctx); 642 f = BN_CTX_get(ctx); 643 ret = BN_CTX_get(ctx); 644 num=BN_num_bytes(rsa->n); 645 buf = OPENSSL_malloc(num); 646 if(!f || !ret || !buf) 647 { 648 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE); 649 goto err; 650 } 651 652 /* This check was for equality but PGP does evil things 653 * and chops off the top '0' bytes */ 654 if (flen > num) 655 { 656 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN); 657 goto err; 658 } 659 660 if (BN_bin2bn(from,flen,f) == NULL) goto err; 661 662 if (BN_ucmp(f, rsa->n) >= 0) 663 { 664 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS); 665 goto err; 666 } 667 668 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) 669 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx)) 670 goto err; 671 672 if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx, 673 rsa->_method_mod_n)) goto err; 674 675 if ((padding == RSA_X931_PADDING) && ((ret->d[0] & 0xf) != 12)) 676 BN_sub(ret, rsa->n, ret); 677 678 p=buf; 679 i=BN_bn2bin(ret,p); 680 681 switch (padding) 682 { 683 case RSA_PKCS1_PADDING: 684 r=RSA_padding_check_PKCS1_type_1(to,num,buf,i,num); 685 break; 686 case RSA_X931_PADDING: 687 r=RSA_padding_check_X931(to,num,buf,i,num); 688 break; 689 case RSA_NO_PADDING: 690 r=RSA_padding_check_none(to,num,buf,i,num); 691 break; 692 default: 693 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE); 694 goto err; 695 } 696 if (r < 0) 697 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_PADDING_CHECK_FAILED); 698 699 err: 700 if (ctx != NULL) 701 { 702 BN_CTX_end(ctx); 703 BN_CTX_free(ctx); 704 } 705 if (buf != NULL) 706 { 707 OPENSSL_cleanse(buf,num); 708 OPENSSL_free(buf); 709 } 710 return(r); 711 } 712 713 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx) 714 { 715 BIGNUM *r1,*m1,*vrfy; 716 BIGNUM local_dmp1,local_dmq1,local_c,local_r1; 717 BIGNUM *dmp1,*dmq1,*c,*pr1; 718 int ret=0; 719 720 BN_CTX_start(ctx); 721 r1 = BN_CTX_get(ctx); 722 m1 = BN_CTX_get(ctx); 723 vrfy = BN_CTX_get(ctx); 724 725 { 726 BIGNUM local_p, local_q; 727 BIGNUM *p = NULL, *q = NULL; 728 729 /* Make sure BN_mod_inverse in Montgomery intialization uses the 730 * BN_FLG_CONSTTIME flag (unless RSA_FLAG_NO_CONSTTIME is set) 731 */ 732 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 733 { 734 BN_init(&local_p); 735 p = &local_p; 736 BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME); 737 738 BN_init(&local_q); 739 q = &local_q; 740 BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME); 741 } 742 else 743 { 744 p = rsa->p; 745 q = rsa->q; 746 } 747 748 if (rsa->flags & RSA_FLAG_CACHE_PRIVATE) 749 { 750 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_p, CRYPTO_LOCK_RSA, p, ctx)) 751 goto err; 752 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_q, CRYPTO_LOCK_RSA, q, ctx)) 753 goto err; 754 } 755 } 756 757 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) 758 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx)) 759 goto err; 760 761 /* compute I mod q */ 762 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 763 { 764 c = &local_c; 765 BN_with_flags(c, I, BN_FLG_CONSTTIME); 766 if (!BN_mod(r1,c,rsa->q,ctx)) goto err; 767 } 768 else 769 { 770 if (!BN_mod(r1,I,rsa->q,ctx)) goto err; 771 } 772 773 /* compute r1^dmq1 mod q */ 774 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 775 { 776 dmq1 = &local_dmq1; 777 BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME); 778 } 779 else 780 dmq1 = rsa->dmq1; 781 if (!rsa->meth->bn_mod_exp(m1,r1,dmq1,rsa->q,ctx, 782 rsa->_method_mod_q)) goto err; 783 784 /* compute I mod p */ 785 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 786 { 787 c = &local_c; 788 BN_with_flags(c, I, BN_FLG_CONSTTIME); 789 if (!BN_mod(r1,c,rsa->p,ctx)) goto err; 790 } 791 else 792 { 793 if (!BN_mod(r1,I,rsa->p,ctx)) goto err; 794 } 795 796 /* compute r1^dmp1 mod p */ 797 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 798 { 799 dmp1 = &local_dmp1; 800 BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME); 801 } 802 else 803 dmp1 = rsa->dmp1; 804 if (!rsa->meth->bn_mod_exp(r0,r1,dmp1,rsa->p,ctx, 805 rsa->_method_mod_p)) goto err; 806 807 if (!BN_sub(r0,r0,m1)) goto err; 808 /* This will help stop the size of r0 increasing, which does 809 * affect the multiply if it optimised for a power of 2 size */ 810 if (BN_is_negative(r0)) 811 if (!BN_add(r0,r0,rsa->p)) goto err; 812 813 if (!BN_mul(r1,r0,rsa->iqmp,ctx)) goto err; 814 815 /* Turn BN_FLG_CONSTTIME flag on before division operation */ 816 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 817 { 818 pr1 = &local_r1; 819 BN_with_flags(pr1, r1, BN_FLG_CONSTTIME); 820 } 821 else 822 pr1 = r1; 823 if (!BN_mod(r0,pr1,rsa->p,ctx)) goto err; 824 825 /* If p < q it is occasionally possible for the correction of 826 * adding 'p' if r0 is negative above to leave the result still 827 * negative. This can break the private key operations: the following 828 * second correction should *always* correct this rare occurrence. 829 * This will *never* happen with OpenSSL generated keys because 830 * they ensure p > q [steve] 831 */ 832 if (BN_is_negative(r0)) 833 if (!BN_add(r0,r0,rsa->p)) goto err; 834 if (!BN_mul(r1,r0,rsa->q,ctx)) goto err; 835 if (!BN_add(r0,r1,m1)) goto err; 836 837 if (rsa->e && rsa->n) 838 { 839 if (!rsa->meth->bn_mod_exp(vrfy,r0,rsa->e,rsa->n,ctx,rsa->_method_mod_n)) goto err; 840 /* If 'I' was greater than (or equal to) rsa->n, the operation 841 * will be equivalent to using 'I mod n'. However, the result of 842 * the verify will *always* be less than 'n' so we don't check 843 * for absolute equality, just congruency. */ 844 if (!BN_sub(vrfy, vrfy, I)) goto err; 845 if (!BN_mod(vrfy, vrfy, rsa->n, ctx)) goto err; 846 if (BN_is_negative(vrfy)) 847 if (!BN_add(vrfy, vrfy, rsa->n)) goto err; 848 if (!BN_is_zero(vrfy)) 849 { 850 /* 'I' and 'vrfy' aren't congruent mod n. Don't leak 851 * miscalculated CRT output, just do a raw (slower) 852 * mod_exp and return that instead. */ 853 854 BIGNUM local_d; 855 BIGNUM *d = NULL; 856 857 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 858 { 859 d = &local_d; 860 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); 861 } 862 else 863 d = rsa->d; 864 if (!rsa->meth->bn_mod_exp(r0,I,d,rsa->n,ctx, 865 rsa->_method_mod_n)) goto err; 866 } 867 } 868 ret=1; 869 err: 870 BN_CTX_end(ctx); 871 return(ret); 872 } 873 874 static int RSA_eay_init(RSA *rsa) 875 { 876 rsa->flags|=RSA_FLAG_CACHE_PUBLIC|RSA_FLAG_CACHE_PRIVATE; 877 return(1); 878 } 879 880 static int RSA_eay_finish(RSA *rsa) 881 { 882 if (rsa->_method_mod_n != NULL) 883 BN_MONT_CTX_free(rsa->_method_mod_n); 884 if (rsa->_method_mod_p != NULL) 885 BN_MONT_CTX_free(rsa->_method_mod_p); 886 if (rsa->_method_mod_q != NULL) 887 BN_MONT_CTX_free(rsa->_method_mod_q); 888 return(1); 889 } 890 891 #endif 892
