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 #ifndef RSA_NULL 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 CRYPTO_THREADID cur; 260 261 CRYPTO_r_lock(CRYPTO_LOCK_RSA); 262 263 if (rsa->blinding == NULL) 264 { 265 CRYPTO_r_unlock(CRYPTO_LOCK_RSA); 266 CRYPTO_w_lock(CRYPTO_LOCK_RSA); 267 got_write_lock = 1; 268 269 if (rsa->blinding == NULL) 270 rsa->blinding = RSA_setup_blinding(rsa, ctx); 271 } 272 273 ret = rsa->blinding; 274 if (ret == NULL) 275 goto err; 276 277 CRYPTO_THREADID_current(&cur); 278 if (!CRYPTO_THREADID_cmp(&cur, BN_BLINDING_thread_id(ret))) 279 { 280 /* rsa->blinding is ours! */ 281 282 *local = 1; 283 } 284 else 285 { 286 /* resort to rsa->mt_blinding instead */ 287 288 *local = 0; /* instructs rsa_blinding_convert(), rsa_blinding_invert() 289 * that the BN_BLINDING is shared, meaning that accesses 290 * require locks, and that the blinding factor must be 291 * stored outside the BN_BLINDING 292 */ 293 294 if (rsa->mt_blinding == NULL) 295 { 296 if (!got_write_lock) 297 { 298 CRYPTO_r_unlock(CRYPTO_LOCK_RSA); 299 CRYPTO_w_lock(CRYPTO_LOCK_RSA); 300 got_write_lock = 1; 301 } 302 303 if (rsa->mt_blinding == NULL) 304 rsa->mt_blinding = RSA_setup_blinding(rsa, ctx); 305 } 306 ret = rsa->mt_blinding; 307 } 308 309 err: 310 if (got_write_lock) 311 CRYPTO_w_unlock(CRYPTO_LOCK_RSA); 312 else 313 CRYPTO_r_unlock(CRYPTO_LOCK_RSA); 314 return ret; 315 } 316 317 static int rsa_blinding_convert(BN_BLINDING *b, int local, BIGNUM *f, 318 BIGNUM *r, BN_CTX *ctx) 319 { 320 if (local) 321 return BN_BLINDING_convert_ex(f, NULL, b, ctx); 322 else 323 { 324 int ret; 325 CRYPTO_r_lock(CRYPTO_LOCK_RSA_BLINDING); 326 ret = BN_BLINDING_convert_ex(f, r, b, ctx); 327 CRYPTO_r_unlock(CRYPTO_LOCK_RSA_BLINDING); 328 return ret; 329 } 330 } 331 332 static int rsa_blinding_invert(BN_BLINDING *b, int local, BIGNUM *f, 333 BIGNUM *r, BN_CTX *ctx) 334 { 335 if (local) 336 return BN_BLINDING_invert_ex(f, NULL, b, ctx); 337 else 338 { 339 int ret; 340 CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING); 341 ret = BN_BLINDING_invert_ex(f, r, b, ctx); 342 CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING); 343 return ret; 344 } 345 } 346 347 /* signing */ 348 static int RSA_eay_private_encrypt(int flen, const unsigned char *from, 349 unsigned char *to, RSA *rsa, int padding) 350 { 351 BIGNUM *f, *ret, *br, *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 BN_BLINDING *blinding = NULL; 357 358 if ((ctx=BN_CTX_new()) == NULL) goto err; 359 BN_CTX_start(ctx); 360 f = BN_CTX_get(ctx); 361 br = BN_CTX_get(ctx); 362 ret = BN_CTX_get(ctx); 363 num = BN_num_bytes(rsa->n); 364 buf = OPENSSL_malloc(num); 365 if(!f || !ret || !buf) 366 { 367 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE); 368 goto err; 369 } 370 371 switch (padding) 372 { 373 case RSA_PKCS1_PADDING: 374 i=RSA_padding_add_PKCS1_type_1(buf,num,from,flen); 375 break; 376 case RSA_X931_PADDING: 377 i=RSA_padding_add_X931(buf,num,from,flen); 378 break; 379 case RSA_NO_PADDING: 380 i=RSA_padding_add_none(buf,num,from,flen); 381 break; 382 case RSA_SSLV23_PADDING: 383 default: 384 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE); 385 goto err; 386 } 387 if (i <= 0) goto err; 388 389 if (BN_bin2bn(buf,num,f) == NULL) goto err; 390 391 if (BN_ucmp(f, rsa->n) >= 0) 392 { 393 /* usually the padding functions would catch this */ 394 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS); 395 goto err; 396 } 397 398 if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) 399 { 400 blinding = rsa_get_blinding(rsa, &local_blinding, ctx); 401 if (blinding == NULL) 402 { 403 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR); 404 goto err; 405 } 406 } 407 408 if (blinding != NULL) 409 if (!rsa_blinding_convert(blinding, local_blinding, f, br, ctx)) 410 goto err; 411 412 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) || 413 ((rsa->p != NULL) && 414 (rsa->q != NULL) && 415 (rsa->dmp1 != NULL) && 416 (rsa->dmq1 != NULL) && 417 (rsa->iqmp != NULL)) ) 418 { 419 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err; 420 } 421 else 422 { 423 BIGNUM local_d; 424 BIGNUM *d = NULL; 425 426 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 427 { 428 BN_init(&local_d); 429 d = &local_d; 430 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); 431 } 432 else 433 d= rsa->d; 434 435 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) 436 if(!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx)) 437 goto err; 438 439 if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx, 440 rsa->_method_mod_n)) goto err; 441 } 442 443 if (blinding) 444 if (!rsa_blinding_invert(blinding, local_blinding, ret, br, ctx)) 445 goto err; 446 447 if (padding == RSA_X931_PADDING) 448 { 449 BN_sub(f, rsa->n, ret); 450 if (BN_cmp(ret, f)) 451 res = f; 452 else 453 res = ret; 454 } 455 else 456 res = ret; 457 458 /* put in leading 0 bytes if the number is less than the 459 * length of the modulus */ 460 j=BN_num_bytes(res); 461 i=BN_bn2bin(res,&(to[num-j])); 462 for (k=0; k<(num-i); k++) 463 to[k]=0; 464 465 r=num; 466 err: 467 if (ctx != NULL) 468 { 469 BN_CTX_end(ctx); 470 BN_CTX_free(ctx); 471 } 472 if (buf != NULL) 473 { 474 OPENSSL_cleanse(buf,num); 475 OPENSSL_free(buf); 476 } 477 return(r); 478 } 479 480 static int RSA_eay_private_decrypt(int flen, const unsigned char *from, 481 unsigned char *to, RSA *rsa, int padding) 482 { 483 BIGNUM *f, *ret, *br; 484 int j,num=0,r= -1; 485 unsigned char *p; 486 unsigned char *buf=NULL; 487 BN_CTX *ctx=NULL; 488 int local_blinding = 0; 489 BN_BLINDING *blinding = NULL; 490 491 if((ctx = BN_CTX_new()) == NULL) goto err; 492 BN_CTX_start(ctx); 493 f = BN_CTX_get(ctx); 494 br = BN_CTX_get(ctx); 495 ret = BN_CTX_get(ctx); 496 num = BN_num_bytes(rsa->n); 497 buf = OPENSSL_malloc(num); 498 if(!f || !ret || !buf) 499 { 500 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE); 501 goto err; 502 } 503 504 /* This check was for equality but PGP does evil things 505 * and chops off the top '0' bytes */ 506 if (flen > num) 507 { 508 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN); 509 goto err; 510 } 511 512 /* make data into a big number */ 513 if (BN_bin2bn(from,(int)flen,f) == NULL) goto err; 514 515 if (BN_ucmp(f, rsa->n) >= 0) 516 { 517 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS); 518 goto err; 519 } 520 521 if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) 522 { 523 blinding = rsa_get_blinding(rsa, &local_blinding, ctx); 524 if (blinding == NULL) 525 { 526 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR); 527 goto err; 528 } 529 } 530 531 if (blinding != NULL) 532 if (!rsa_blinding_convert(blinding, local_blinding, f, br, ctx)) 533 goto err; 534 535 /* do the decrypt */ 536 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) || 537 ((rsa->p != NULL) && 538 (rsa->q != NULL) && 539 (rsa->dmp1 != NULL) && 540 (rsa->dmq1 != NULL) && 541 (rsa->iqmp != NULL)) ) 542 { 543 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err; 544 } 545 else 546 { 547 BIGNUM local_d; 548 BIGNUM *d = NULL; 549 550 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 551 { 552 d = &local_d; 553 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); 554 } 555 else 556 d = rsa->d; 557 558 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) 559 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx)) 560 goto err; 561 if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx, 562 rsa->_method_mod_n)) 563 goto err; 564 } 565 566 if (blinding) 567 if (!rsa_blinding_invert(blinding, local_blinding, ret, br, ctx)) 568 goto err; 569 570 p=buf; 571 j=BN_bn2bin(ret,p); /* j is only used with no-padding mode */ 572 573 switch (padding) 574 { 575 case RSA_PKCS1_PADDING: 576 r=RSA_padding_check_PKCS1_type_2(to,num,buf,j,num); 577 break; 578 #ifndef OPENSSL_NO_SHA 579 case RSA_PKCS1_OAEP_PADDING: 580 r=RSA_padding_check_PKCS1_OAEP(to,num,buf,j,num,NULL,0); 581 break; 582 #endif 583 case RSA_SSLV23_PADDING: 584 r=RSA_padding_check_SSLv23(to,num,buf,j,num); 585 break; 586 case RSA_NO_PADDING: 587 r=RSA_padding_check_none(to,num,buf,j,num); 588 break; 589 default: 590 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE); 591 goto err; 592 } 593 if (r < 0) 594 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_PADDING_CHECK_FAILED); 595 596 err: 597 if (ctx != NULL) 598 { 599 BN_CTX_end(ctx); 600 BN_CTX_free(ctx); 601 } 602 if (buf != NULL) 603 { 604 OPENSSL_cleanse(buf,num); 605 OPENSSL_free(buf); 606 } 607 return(r); 608 } 609 610 /* signature verification */ 611 static int RSA_eay_public_decrypt(int flen, const unsigned char *from, 612 unsigned char *to, RSA *rsa, int padding) 613 { 614 BIGNUM *f,*ret; 615 int i,num=0,r= -1; 616 unsigned char *p; 617 unsigned char *buf=NULL; 618 BN_CTX *ctx=NULL; 619 620 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) 621 { 622 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE); 623 return -1; 624 } 625 626 if (BN_ucmp(rsa->n, rsa->e) <= 0) 627 { 628 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE); 629 return -1; 630 } 631 632 /* for large moduli, enforce exponent limit */ 633 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) 634 { 635 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) 636 { 637 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE); 638 return -1; 639 } 640 } 641 642 if((ctx = BN_CTX_new()) == NULL) goto err; 643 BN_CTX_start(ctx); 644 f = BN_CTX_get(ctx); 645 ret = BN_CTX_get(ctx); 646 num=BN_num_bytes(rsa->n); 647 buf = OPENSSL_malloc(num); 648 if(!f || !ret || !buf) 649 { 650 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE); 651 goto err; 652 } 653 654 /* This check was for equality but PGP does evil things 655 * and chops off the top '0' bytes */ 656 if (flen > num) 657 { 658 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN); 659 goto err; 660 } 661 662 if (BN_bin2bn(from,flen,f) == NULL) goto err; 663 664 if (BN_ucmp(f, rsa->n) >= 0) 665 { 666 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS); 667 goto err; 668 } 669 670 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) 671 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx)) 672 goto err; 673 674 if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx, 675 rsa->_method_mod_n)) goto err; 676 677 if ((padding == RSA_X931_PADDING) && ((ret->d[0] & 0xf) != 12)) 678 if (!BN_sub(ret, rsa->n, ret)) goto err; 679 680 p=buf; 681 i=BN_bn2bin(ret,p); 682 683 switch (padding) 684 { 685 case RSA_PKCS1_PADDING: 686 r=RSA_padding_check_PKCS1_type_1(to,num,buf,i,num); 687 break; 688 case RSA_X931_PADDING: 689 r=RSA_padding_check_X931(to,num,buf,i,num); 690 break; 691 case RSA_NO_PADDING: 692 r=RSA_padding_check_none(to,num,buf,i,num); 693 break; 694 default: 695 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE); 696 goto err; 697 } 698 if (r < 0) 699 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_PADDING_CHECK_FAILED); 700 701 err: 702 if (ctx != NULL) 703 { 704 BN_CTX_end(ctx); 705 BN_CTX_free(ctx); 706 } 707 if (buf != NULL) 708 { 709 OPENSSL_cleanse(buf,num); 710 OPENSSL_free(buf); 711 } 712 return(r); 713 } 714 715 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx) 716 { 717 BIGNUM *r1,*m1,*vrfy; 718 BIGNUM local_dmp1,local_dmq1,local_c,local_r1; 719 BIGNUM *dmp1,*dmq1,*c,*pr1; 720 int ret=0; 721 722 BN_CTX_start(ctx); 723 r1 = BN_CTX_get(ctx); 724 m1 = BN_CTX_get(ctx); 725 vrfy = BN_CTX_get(ctx); 726 727 { 728 BIGNUM local_p, local_q; 729 BIGNUM *p = NULL, *q = NULL; 730 731 /* Make sure BN_mod_inverse in Montgomery intialization uses the 732 * BN_FLG_CONSTTIME flag (unless RSA_FLAG_NO_CONSTTIME is set) 733 */ 734 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 735 { 736 BN_init(&local_p); 737 p = &local_p; 738 BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME); 739 740 BN_init(&local_q); 741 q = &local_q; 742 BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME); 743 } 744 else 745 { 746 p = rsa->p; 747 q = rsa->q; 748 } 749 750 if (rsa->flags & RSA_FLAG_CACHE_PRIVATE) 751 { 752 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_p, CRYPTO_LOCK_RSA, p, ctx)) 753 goto err; 754 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_q, CRYPTO_LOCK_RSA, q, ctx)) 755 goto err; 756 } 757 } 758 759 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) 760 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx)) 761 goto err; 762 763 /* compute I mod q */ 764 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 765 { 766 c = &local_c; 767 BN_with_flags(c, I, BN_FLG_CONSTTIME); 768 if (!BN_mod(r1,c,rsa->q,ctx)) goto err; 769 } 770 else 771 { 772 if (!BN_mod(r1,I,rsa->q,ctx)) goto err; 773 } 774 775 /* compute r1^dmq1 mod q */ 776 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 777 { 778 dmq1 = &local_dmq1; 779 BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME); 780 } 781 else 782 dmq1 = rsa->dmq1; 783 if (!rsa->meth->bn_mod_exp(m1,r1,dmq1,rsa->q,ctx, 784 rsa->_method_mod_q)) goto err; 785 786 /* compute I mod p */ 787 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 788 { 789 c = &local_c; 790 BN_with_flags(c, I, BN_FLG_CONSTTIME); 791 if (!BN_mod(r1,c,rsa->p,ctx)) goto err; 792 } 793 else 794 { 795 if (!BN_mod(r1,I,rsa->p,ctx)) goto err; 796 } 797 798 /* compute r1^dmp1 mod p */ 799 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 800 { 801 dmp1 = &local_dmp1; 802 BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME); 803 } 804 else 805 dmp1 = rsa->dmp1; 806 if (!rsa->meth->bn_mod_exp(r0,r1,dmp1,rsa->p,ctx, 807 rsa->_method_mod_p)) goto err; 808 809 if (!BN_sub(r0,r0,m1)) goto err; 810 /* This will help stop the size of r0 increasing, which does 811 * affect the multiply if it optimised for a power of 2 size */ 812 if (BN_is_negative(r0)) 813 if (!BN_add(r0,r0,rsa->p)) goto err; 814 815 if (!BN_mul(r1,r0,rsa->iqmp,ctx)) goto err; 816 817 /* Turn BN_FLG_CONSTTIME flag on before division operation */ 818 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 819 { 820 pr1 = &local_r1; 821 BN_with_flags(pr1, r1, BN_FLG_CONSTTIME); 822 } 823 else 824 pr1 = r1; 825 if (!BN_mod(r0,pr1,rsa->p,ctx)) goto err; 826 827 /* If p < q it is occasionally possible for the correction of 828 * adding 'p' if r0 is negative above to leave the result still 829 * negative. This can break the private key operations: the following 830 * second correction should *always* correct this rare occurrence. 831 * This will *never* happen with OpenSSL generated keys because 832 * they ensure p > q [steve] 833 */ 834 if (BN_is_negative(r0)) 835 if (!BN_add(r0,r0,rsa->p)) goto err; 836 if (!BN_mul(r1,r0,rsa->q,ctx)) goto err; 837 if (!BN_add(r0,r1,m1)) goto err; 838 839 if (rsa->e && rsa->n) 840 { 841 if (!rsa->meth->bn_mod_exp(vrfy,r0,rsa->e,rsa->n,ctx,rsa->_method_mod_n)) goto err; 842 /* If 'I' was greater than (or equal to) rsa->n, the operation 843 * will be equivalent to using 'I mod n'. However, the result of 844 * the verify will *always* be less than 'n' so we don't check 845 * for absolute equality, just congruency. */ 846 if (!BN_sub(vrfy, vrfy, I)) goto err; 847 if (!BN_mod(vrfy, vrfy, rsa->n, ctx)) goto err; 848 if (BN_is_negative(vrfy)) 849 if (!BN_add(vrfy, vrfy, rsa->n)) goto err; 850 if (!BN_is_zero(vrfy)) 851 { 852 /* 'I' and 'vrfy' aren't congruent mod n. Don't leak 853 * miscalculated CRT output, just do a raw (slower) 854 * mod_exp and return that instead. */ 855 856 BIGNUM local_d; 857 BIGNUM *d = NULL; 858 859 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) 860 { 861 d = &local_d; 862 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); 863 } 864 else 865 d = rsa->d; 866 if (!rsa->meth->bn_mod_exp(r0,I,d,rsa->n,ctx, 867 rsa->_method_mod_n)) goto err; 868 } 869 } 870 ret=1; 871 err: 872 BN_CTX_end(ctx); 873 return(ret); 874 } 875 876 static int RSA_eay_init(RSA *rsa) 877 { 878 rsa->flags|=RSA_FLAG_CACHE_PUBLIC|RSA_FLAG_CACHE_PRIVATE; 879 return(1); 880 } 881 882 static int RSA_eay_finish(RSA *rsa) 883 { 884 if (rsa->_method_mod_n != NULL) 885 BN_MONT_CTX_free(rsa->_method_mod_n); 886 if (rsa->_method_mod_p != NULL) 887 BN_MONT_CTX_free(rsa->_method_mod_p); 888 if (rsa->_method_mod_q != NULL) 889 BN_MONT_CTX_free(rsa->_method_mod_q); 890 return(1); 891 } 892 893 #endif 894
