crypto/rsa/rsa_eay.c

   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 #define OPENSSL_FIPSAPI
 113
 114 #include <stdio.h>
 115 #include "cryptlib.h"
 116 #include <openssl/bn.h>
 117 #include <openssl/rsa.h>
 118 #include <openssl/rand.h>
 119 #ifdef OPENSSL_FIPS
 120 #include <openssl/fips.h>
 121 #endif
 122
 123 #ifndef RSA_NULL
 124
 125 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
 126                 unsigned char *to, RSA *rsa,int padding);
 127 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
 128                 unsigned char *to, RSA *rsa,int padding);
 129 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
 130                 unsigned char *to, RSA *rsa,int padding);
 131 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
 132                 unsigned char *to, RSA *rsa,int padding);
 133 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *i, RSA *rsa, BN_CTX *ctx);
 134 static int RSA_eay_init(RSA *rsa);
 135 static int RSA_eay_finish(RSA *rsa);
 136 static RSA_METHOD rsa_pkcs1_eay_meth={
 137         "Eric Young's PKCS#1 RSA",
 138         RSA_eay_public_encrypt,
 139         RSA_eay_public_decrypt, /* signature verification */
 140         RSA_eay_private_encrypt, /* signing */
 141         RSA_eay_private_decrypt,
 142         RSA_eay_mod_exp,
 143         BN_mod_exp_mont, /* XXX probably we should not use Montgomery if  e == 3 */
 144         RSA_eay_init,
 145         RSA_eay_finish,
 146         RSA_FLAG_FIPS_METHOD, /* flags */
 147         NULL,
 148         0, /* rsa_sign */
 149         0, /* rsa_verify */
 150         NULL /* rsa_keygen */
 151         };
 152
 153 const RSA_METHOD *RSA_PKCS1_SSLeay(void)
 154         {
 155         return(&rsa_pkcs1_eay_meth);
 156         }
 157
 158 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
 159              unsigned char *to, RSA *rsa, int padding)
 160         {
 161         BIGNUM *f,*ret;
 162         int i,j,k,num=0,r= -1;
 163         unsigned char *buf=NULL;
 164         BN_CTX *ctx=NULL;
 165
 166 #ifdef OPENSSL_FIPS
 167         if(FIPS_selftest_failed())
 168                 {
 169                 FIPSerr(FIPS_F_RSA_EAY_PUBLIC_ENCRYPT,FIPS_R_FIPS_SELFTEST_FAILED);
 170                 goto err;
 171                 }
 172
 173         if (FIPS_module_mode() && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)
 174                 && (BN_num_bits(rsa->n) < OPENSSL_RSA_FIPS_MIN_MODULUS_BITS))
 175                 {
 176                 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_KEY_SIZE_TOO_SMALL);
 177                 return -1;
 178                 }
 179 #endif
 180
 181         if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS)
 182                 {
 183                 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_MODULUS_TOO_LARGE);
 184                 return -1;
 185                 }
 186
 187         if (BN_ucmp(rsa->n, rsa->e) <= 0)
 188                 {
 189                 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
 190                 return -1;
 191                 }
 192
 193         /* for large moduli, enforce exponent limit */
 194         if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS)
 195                 {
 196                 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS)
 197                         {
 198                         RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
 199                         return -1;
 200                         }
 201                 }
 202
 203         if ((ctx=BN_CTX_new()) == NULL) goto err;
 204         BN_CTX_start(ctx);
 205         f = BN_CTX_get(ctx);
 206         ret = BN_CTX_get(ctx);
 207         num=BN_num_bytes(rsa->n);
 208         buf = OPENSSL_malloc(num);
 209         if (!f || !ret || !buf)
 210                 {
 211                 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,ERR_R_MALLOC_FAILURE);
 212                 goto err;
 213                 }
 214
 215         switch (padding)
 216                 {
 217         case RSA_PKCS1_PADDING:
 218                 i=RSA_padding_add_PKCS1_type_2(buf,num,from,flen);
 219                 break;
 220 #ifndef OPENSSL_NO_SHA
 221         case RSA_PKCS1_OAEP_PADDING:
 222                 i=RSA_padding_add_PKCS1_OAEP(buf,num,from,flen,NULL,0);
 223                 break;
 224 #endif
 225         case RSA_SSLV23_PADDING:
 226                 i=RSA_padding_add_SSLv23(buf,num,from,flen);
 227                 break;
 228         case RSA_NO_PADDING:
 229                 i=RSA_padding_add_none(buf,num,from,flen);
 230                 break;
 231         default:
 232                 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
 233                 goto err;
 234                 }
 235         if (i <= 0) goto err;
 236
 237         if (BN_bin2bn(buf,num,f) == NULL) goto err;
 238
 239         if (BN_ucmp(f, rsa->n) >= 0)
 240                 {
 241                 /* usually the padding functions would catch this */
 242                 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
 243                 goto err;
 244                 }
 245
 246         if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
 247                 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
 248                         goto err;
 249
 250         if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx,
 251                 rsa->_method_mod_n)) goto err;
 252
 253         /* put in leading 0 bytes if the number is less than the
 254          * length of the modulus */
 255         j=BN_num_bytes(ret);
 256         i=BN_bn2bin(ret,&(to[num-j]));
 257         for (k=0; k<(num-i); k++)
 258                 to[k]=0;
 259
 260         r=num;
 261 err:
 262         if (ctx != NULL)
 263                 {
 264                 BN_CTX_end(ctx);
 265                 BN_CTX_free(ctx);
 266                 }
 267         if (buf != NULL)
 268                 {
 269                 OPENSSL_cleanse(buf,num);
 270                 OPENSSL_free(buf);
 271                 }
 272         return(r);
 273         }
 274
 275 static BN_BLINDING *rsa_get_blinding(RSA *rsa, int *local, BN_CTX *ctx)
 276 {
 277         BN_BLINDING *ret;
 278         int got_write_lock = 0;
 279         CRYPTO_THREADID cur;
 280
 281         CRYPTO_r_lock(CRYPTO_LOCK_RSA);
 282
 283         if (rsa->blinding == NULL)
 284                 {
 285                 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
 286                 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
 287                 got_write_lock = 1;
 288
 289                 if (rsa->blinding == NULL)
 290                         rsa->blinding = RSA_setup_blinding(rsa, ctx);
 291                 }
 292
 293         ret = rsa->blinding;
 294         if (ret == NULL)
 295                 goto err;
 296
 297         CRYPTO_THREADID_current(&cur);
 298         if (!CRYPTO_THREADID_cmp(&cur, BN_BLINDING_thread_id(ret)))
 299                 {
 300                 /* rsa->blinding is ours! */
 301
 302                 *local = 1;
 303                 }
 304         else
 305                 {
 306                 /* resort to rsa->mt_blinding instead */
 307
 308                 *local = 0; /* instructs rsa_blinding_convert(), rsa_blinding_invert()
 309                              * that the BN_BLINDING is shared, meaning that accesses
 310                              * require locks, and that the blinding factor must be
 311                              * stored outside the BN_BLINDING
 312                              */
 313
 314                 if (rsa->mt_blinding == NULL)
 315                         {
 316                         if (!got_write_lock)
 317                                 {
 318                                 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
 319                                 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
 320                                 got_write_lock = 1;
 321                                 }
 322
 323                         if (rsa->mt_blinding == NULL)
 324                                 rsa->mt_blinding = RSA_setup_blinding(rsa, ctx);
 325                         }
 326                 ret = rsa->mt_blinding;
 327                 }
 328
 329  err:
 330         if (got_write_lock)
 331                 CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
 332         else
 333                 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
 334         return ret;
 335 }
 336
 337 static int rsa_blinding_convert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
 338         BN_CTX *ctx)
 339         {
 340         if (unblind == NULL)
 341                 /* Local blinding: store the unblinding factor
 342                  * in BN_BLINDING. */
 343                 return BN_BLINDING_convert_ex(f, NULL, b, ctx);
 344         else
 345                 {
 346                 /* Shared blinding: store the unblinding factor
 347                  * outside BN_BLINDING. */
 348                 int ret;
 349                 CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING);
 350                 ret = BN_BLINDING_convert_ex(f, unblind, b, ctx);
 351                 CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING);
 352                 return ret;
 353                 }
 354         }
 355
 356 static int rsa_blinding_invert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
 357         BN_CTX *ctx)
 358         {
 359         /* For local blinding, unblind is set to NULL, and BN_BLINDING_invert_ex
 360          * will use the unblinding factor stored in BN_BLINDING.
 361          * If BN_BLINDING is shared between threads, unblind must be non-null:
 362          * BN_BLINDING_invert_ex will then use the local unblinding factor,
 363          * and will only read the modulus from BN_BLINDING.
 364          * In both cases it's safe to access the blinding without a lock.
 365          */
 366         return BN_BLINDING_invert_ex(f, unblind, b, ctx);
 367         }
 368
 369 /* signing */
 370 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
 371              unsigned char *to, RSA *rsa, int padding)
 372         {
 373         BIGNUM *f, *ret, *res;
 374         int i,j,k,num=0,r= -1;
 375         unsigned char *buf=NULL;
 376         BN_CTX *ctx=NULL;
 377         int local_blinding = 0;
 378         /* Used only if the blinding structure is shared. A non-NULL unblind
 379          * instructs rsa_blinding_convert() and rsa_blinding_invert() to store
 380          * the unblinding factor outside the blinding structure. */
 381         BIGNUM *unblind = NULL;
 382         BN_BLINDING *blinding = NULL;
 383
 384 #ifdef OPENSSL_FIPS
 385         if(FIPS_selftest_failed())
 386                 {
 387                 FIPSerr(FIPS_F_RSA_EAY_PRIVATE_ENCRYPT,FIPS_R_FIPS_SELFTEST_FAILED);
 388                 goto err;
 389                 }
 390
 391         if (FIPS_module_mode() && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)
 392                 && (BN_num_bits(rsa->n) < OPENSSL_RSA_FIPS_MIN_MODULUS_BITS))
 393                 {
 394                 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, RSA_R_KEY_SIZE_TOO_SMALL);
 395                 return -1;
 396                 }
 397 #endif
 398
 399         if ((ctx=BN_CTX_new()) == NULL) goto err;
 400         BN_CTX_start(ctx);
 401         f   = BN_CTX_get(ctx);
 402         ret = BN_CTX_get(ctx);
 403         num = BN_num_bytes(rsa->n);
 404         buf = OPENSSL_malloc(num);
 405         if(!f || !ret || !buf)
 406                 {
 407                 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);
 408                 goto err;
 409                 }
 410
 411         switch (padding)
 412                 {
 413         case RSA_PKCS1_PADDING:
 414                 i=RSA_padding_add_PKCS1_type_1(buf,num,from,flen);
 415                 break;
 416         case RSA_X931_PADDING:
 417                 i=RSA_padding_add_X931(buf,num,from,flen);
 418                 break;
 419         case RSA_NO_PADDING:
 420                 i=RSA_padding_add_none(buf,num,from,flen);
 421                 break;
 422         case RSA_SSLV23_PADDING:
 423         default:
 424                 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
 425                 goto err;
 426                 }
 427         if (i <= 0) goto err;
 428
 429         if (BN_bin2bn(buf,num,f) == NULL) goto err;
 430
 431         if (BN_ucmp(f, rsa->n) >= 0)
 432                 {
 433                 /* usually the padding functions would catch this */
 434                 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
 435                 goto err;
 436                 }
 437
 438         if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
 439                 {
 440                 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
 441                 if (blinding == NULL)
 442                         {
 443                         RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);
 444                         goto err;
 445                         }
 446                 }
 447
 448         if (blinding != NULL)
 449                 {
 450                 if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL))
 451                         {
 452                         RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);
 453                         goto err;
 454                         }
 455                 if (!rsa_blinding_convert(blinding, f, unblind, ctx))
 456                         goto err;
 457                 }
 458
 459         if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
 460                 ((rsa->p != NULL) &&
 461                 (rsa->q != NULL) &&
 462                 (rsa->dmp1 != NULL) &&
 463                 (rsa->dmq1 != NULL) &&
 464                 (rsa->iqmp != NULL)) )
 465                 {
 466                 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err;
 467                 }
 468         else
 469                 {
 470                 BIGNUM local_d;
 471                 BIGNUM *d = NULL;
 472
 473                 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 474                         {
 475                         BN_init(&local_d);
 476                         d = &local_d;
 477                         BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
 478                         }
 479                 else
 480                         d= rsa->d;
 481
 482                 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
 483                         if(!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
 484                                 goto err;
 485
 486                 if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx,
 487                                 rsa->_method_mod_n)) goto err;
 488                 }
 489
 490         if (blinding)
 491                 if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
 492                         goto err;
 493
 494         if (padding == RSA_X931_PADDING)
 495                 {
 496                 BN_sub(f, rsa->n, ret);
 497                 if (BN_cmp(ret, f))
 498                         res = f;
 499                 else
 500                         res = ret;
 501                 }
 502         else
 503                 res = ret;
 504
 505         /* put in leading 0 bytes if the number is less than the
 506          * length of the modulus */
 507         j=BN_num_bytes(res);
 508         i=BN_bn2bin(res,&(to[num-j]));
 509         for (k=0; k<(num-i); k++)
 510                 to[k]=0;
 511
 512         r=num;
 513 err:
 514         if (ctx != NULL)
 515                 {
 516                 BN_CTX_end(ctx);
 517                 BN_CTX_free(ctx);
 518                 }
 519         if (buf != NULL)
 520                 {
 521                 OPENSSL_cleanse(buf,num);
 522                 OPENSSL_free(buf);
 523                 }
 524         return(r);
 525         }
 526
 527 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
 528              unsigned char *to, RSA *rsa, int padding)
 529         {
 530         BIGNUM *f, *ret;
 531         int j,num=0,r= -1;
 532         unsigned char *p;
 533         unsigned char *buf=NULL;
 534         BN_CTX *ctx=NULL;
 535         int local_blinding = 0;
 536         /* Used only if the blinding structure is shared. A non-NULL unblind
 537          * instructs rsa_blinding_convert() and rsa_blinding_invert() to store
 538          * the unblinding factor outside the blinding structure. */
 539         BIGNUM *unblind = NULL;
 540         BN_BLINDING *blinding = NULL;
 541
 542 #ifdef OPENSSL_FIPS
 543         if(FIPS_selftest_failed())
 544                 {
 545                 FIPSerr(FIPS_F_RSA_EAY_PRIVATE_DECRYPT,FIPS_R_FIPS_SELFTEST_FAILED);
 546                 goto err;
 547                 }
 548
 549         if (FIPS_module_mode() && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)
 550                 && (BN_num_bits(rsa->n) < OPENSSL_RSA_FIPS_MIN_MODULUS_BITS))
 551                 {
 552                 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, RSA_R_KEY_SIZE_TOO_SMALL);
 553                 return -1;
 554                 }
 555 #endif
 556
 557         if((ctx = BN_CTX_new()) == NULL) goto err;
 558         BN_CTX_start(ctx);
 559         f   = BN_CTX_get(ctx);
 560         ret = BN_CTX_get(ctx);
 561         num = BN_num_bytes(rsa->n);
 562         buf = OPENSSL_malloc(num);
 563         if(!f || !ret || !buf)
 564                 {
 565                 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
 566                 goto err;
 567                 }
 568
 569         /* This check was for equality but PGP does evil things
 570          * and chops off the top '0' bytes */
 571         if (flen > num)
 572                 {
 573                 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
 574                 goto err;
 575                 }
 576
 577         /* make data into a big number */
 578         if (BN_bin2bn(from,(int)flen,f) == NULL) goto err;
 579
 580         if (BN_ucmp(f, rsa->n) >= 0)
 581                 {
 582                 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
 583                 goto err;
 584                 }
 585
 586         if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
 587                 {
 588                 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
 589                 if (blinding == NULL)
 590                         {
 591                         RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);
 592                         goto err;
 593                         }
 594                 }
 595
 596         if (blinding != NULL)
 597                 {
 598                 if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL))
 599                         {
 600                         RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
 601                         goto err;
 602                         }
 603                 if (!rsa_blinding_convert(blinding, f, unblind, ctx))
 604                         goto err;
 605                 }
 606
 607         /* do the decrypt */
 608         if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
 609                 ((rsa->p != NULL) &&
 610                 (rsa->q != NULL) &&
 611                 (rsa->dmp1 != NULL) &&
 612                 (rsa->dmq1 != NULL) &&
 613                 (rsa->iqmp != NULL)) )
 614                 {
 615                 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err;
 616                 }
 617         else
 618                 {
 619                 BIGNUM local_d;
 620                 BIGNUM *d = NULL;
 621
 622                 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 623                         {
 624                         d = &local_d;
 625                         BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
 626                         }
 627                 else
 628                         d = rsa->d;
 629
 630                 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
 631                         if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
 632                                 goto err;
 633                 if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx,
 634                                 rsa->_method_mod_n))
 635                   goto err;
 636                 }
 637
 638         if (blinding)
 639                 if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
 640                         goto err;
 641
 642         p=buf;
 643         j=BN_bn2bin(ret,p); /* j is only used with no-padding mode */
 644
 645         switch (padding)
 646                 {
 647         case RSA_PKCS1_PADDING:
 648                 r=RSA_padding_check_PKCS1_type_2(to,num,buf,j,num);
 649                 break;
 650 #ifndef OPENSSL_NO_SHA
 651         case RSA_PKCS1_OAEP_PADDING:
 652                 r=RSA_padding_check_PKCS1_OAEP(to,num,buf,j,num,NULL,0);
 653                 break;
 654 #endif
 655         case RSA_SSLV23_PADDING:
 656                 r=RSA_padding_check_SSLv23(to,num,buf,j,num);
 657                 break;
 658         case RSA_NO_PADDING:
 659                 r=RSA_padding_check_none(to,num,buf,j,num);
 660                 break;
 661         default:
 662                 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
 663                 goto err;
 664                 }
 665         if (r < 0)
 666                 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
 667
 668 err:
 669         if (ctx != NULL)
 670                 {
 671                 BN_CTX_end(ctx);
 672                 BN_CTX_free(ctx);
 673                 }
 674         if (buf != NULL)
 675                 {
 676                 OPENSSL_cleanse(buf,num);
 677                 OPENSSL_free(buf);
 678                 }
 679         return(r);
 680         }
 681
 682 /* signature verification */
 683 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
 684              unsigned char *to, RSA *rsa, int padding)
 685         {
 686         BIGNUM *f,*ret;
 687         int i,num=0,r= -1;
 688         unsigned char *p;
 689         unsigned char *buf=NULL;
 690         BN_CTX *ctx=NULL;
 691
 692 #ifdef OPENSSL_FIPS
 693         if(FIPS_selftest_failed())
 694                 {
 695                 FIPSerr(FIPS_F_RSA_EAY_PUBLIC_DECRYPT,FIPS_R_FIPS_SELFTEST_FAILED);
 696                 goto err;
 697                 }
 698
 699         if (FIPS_module_mode() && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)
 700                 && (BN_num_bits(rsa->n) < OPENSSL_RSA_FIPS_MIN_MODULUS_BITS))
 701                 {
 702                 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_KEY_SIZE_TOO_SMALL);
 703                 return -1;
 704                 }
 705 #endif
 706
 707         if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS)
 708                 {
 709                 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE);
 710                 return -1;
 711                 }
 712
 713         if (BN_ucmp(rsa->n, rsa->e) <= 0)
 714                 {
 715                 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
 716                 return -1;
 717                 }
 718
 719         /* for large moduli, enforce exponent limit */
 720         if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS)
 721                 {
 722                 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS)
 723                         {
 724                         RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
 725                         return -1;
 726                         }
 727                 }
 728
 729         if((ctx = BN_CTX_new()) == NULL) goto err;
 730         BN_CTX_start(ctx);
 731         f = BN_CTX_get(ctx);
 732         ret = BN_CTX_get(ctx);
 733         num=BN_num_bytes(rsa->n);
 734         buf = OPENSSL_malloc(num);
 735         if(!f || !ret || !buf)
 736                 {
 737                 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE);
 738                 goto err;
 739                 }
 740
 741         /* This check was for equality but PGP does evil things
 742          * and chops off the top '0' bytes */
 743         if (flen > num)
 744                 {
 745                 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
 746                 goto err;
 747                 }
 748
 749         if (BN_bin2bn(from,flen,f) == NULL) goto err;
 750
 751         if (BN_ucmp(f, rsa->n) >= 0)
 752                 {
 753                 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
 754                 goto err;
 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         if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx,
 762                 rsa->_method_mod_n)) goto err;
 763
 764         if ((padding == RSA_X931_PADDING) && ((ret->d[0] & 0xf) != 12))
 765                 if (!BN_sub(ret, rsa->n, ret)) goto err;
 766
 767         p=buf;
 768         i=BN_bn2bin(ret,p);
 769
 770         switch (padding)
 771                 {
 772         case RSA_PKCS1_PADDING:
 773                 r=RSA_padding_check_PKCS1_type_1(to,num,buf,i,num);
 774                 break;
 775         case RSA_X931_PADDING:
 776                 r=RSA_padding_check_X931(to,num,buf,i,num);
 777                 break;
 778         case RSA_NO_PADDING:
 779                 r=RSA_padding_check_none(to,num,buf,i,num);
 780                 break;
 781         default:
 782                 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
 783                 goto err;
 784                 }
 785         if (r < 0)
 786                 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
 787
 788 err:
 789         if (ctx != NULL)
 790                 {
 791                 BN_CTX_end(ctx);
 792                 BN_CTX_free(ctx);
 793                 }
 794         if (buf != NULL)
 795                 {
 796                 OPENSSL_cleanse(buf,num);
 797                 OPENSSL_free(buf);
 798                 }
 799         return(r);
 800         }
 801
 802 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
 803         {
 804         BIGNUM *r1,*m1,*vrfy;
 805         BIGNUM local_dmp1,local_dmq1,local_c,local_r1;
 806         BIGNUM *dmp1,*dmq1,*c,*pr1;
 807         int ret=0;
 808
 809         BN_CTX_start(ctx);
 810         r1 = BN_CTX_get(ctx);
 811         m1 = BN_CTX_get(ctx);
 812         vrfy = BN_CTX_get(ctx);
 813
 814         {
 815                 BIGNUM local_p, local_q;
 816                 BIGNUM *p = NULL, *q = NULL;
 817
 818                 /* Make sure BN_mod_inverse in Montgomery intialization uses the
 819                  * BN_FLG_CONSTTIME flag (unless RSA_FLAG_NO_CONSTTIME is set)
 820                  */
 821                 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 822                         {
 823                         BN_init(&local_p);
 824                         p = &local_p;
 825                         BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
 826
 827                         BN_init(&local_q);
 828                         q = &local_q;
 829                         BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME);
 830                         }
 831                 else
 832                         {
 833                         p = rsa->p;
 834                         q = rsa->q;
 835                         }
 836
 837                 if (rsa->flags & RSA_FLAG_CACHE_PRIVATE)
 838                         {
 839                         if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_p, CRYPTO_LOCK_RSA, p, ctx))
 840                                 goto err;
 841                         if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_q, CRYPTO_LOCK_RSA, q, ctx))
 842                                 goto err;
 843                         }
 844         }
 845
 846         if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
 847                 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
 848                         goto err;
 849
 850         /* compute I mod q */
 851         if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 852                 {
 853                 c = &local_c;
 854                 BN_with_flags(c, I, BN_FLG_CONSTTIME);
 855                 if (!BN_mod(r1,c,rsa->q,ctx)) goto err;
 856                 }
 857         else
 858                 {
 859                 if (!BN_mod(r1,I,rsa->q,ctx)) goto err;
 860                 }
 861
 862         /* compute r1^dmq1 mod q */
 863         if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 864                 {
 865                 dmq1 = &local_dmq1;
 866                 BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
 867                 }
 868         else
 869                 dmq1 = rsa->dmq1;
 870         if (!rsa->meth->bn_mod_exp(m1,r1,dmq1,rsa->q,ctx,
 871                 rsa->_method_mod_q)) goto err;
 872
 873         /* compute I mod p */
 874         if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 875                 {
 876                 c = &local_c;
 877                 BN_with_flags(c, I, BN_FLG_CONSTTIME);
 878                 if (!BN_mod(r1,c,rsa->p,ctx)) goto err;
 879                 }
 880         else
 881                 {
 882                 if (!BN_mod(r1,I,rsa->p,ctx)) goto err;
 883                 }
 884
 885         /* compute r1^dmp1 mod p */
 886         if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 887                 {
 888                 dmp1 = &local_dmp1;
 889                 BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
 890                 }
 891         else
 892                 dmp1 = rsa->dmp1;
 893         if (!rsa->meth->bn_mod_exp(r0,r1,dmp1,rsa->p,ctx,
 894                 rsa->_method_mod_p)) goto err;
 895
 896         if (!BN_sub(r0,r0,m1)) goto err;
 897         /* This will help stop the size of r0 increasing, which does
 898          * affect the multiply if it optimised for a power of 2 size */
 899         if (BN_is_negative(r0))
 900                 if (!BN_add(r0,r0,rsa->p)) goto err;
 901
 902         if (!BN_mul(r1,r0,rsa->iqmp,ctx)) goto err;
 903
 904         /* Turn BN_FLG_CONSTTIME flag on before division operation */
 905         if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 906                 {
 907                 pr1 = &local_r1;
 908                 BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
 909                 }
 910         else
 911                 pr1 = r1;
 912         if (!BN_mod(r0,pr1,rsa->p,ctx)) goto err;
 913
 914         /* If p < q it is occasionally possible for the correction of
 915          * adding 'p' if r0 is negative above to leave the result still
 916          * negative. This can break the private key operations: the following
 917          * second correction should *always* correct this rare occurrence.
 918          * This will *never* happen with OpenSSL generated keys because
 919          * they ensure p > q [steve]
 920          */
 921         if (BN_is_negative(r0))
 922                 if (!BN_add(r0,r0,rsa->p)) goto err;
 923         if (!BN_mul(r1,r0,rsa->q,ctx)) goto err;
 924         if (!BN_add(r0,r1,m1)) goto err;
 925
 926         if (rsa->e && rsa->n)
 927                 {
 928                 if (!rsa->meth->bn_mod_exp(vrfy,r0,rsa->e,rsa->n,ctx,rsa->_method_mod_n)) goto err;
 929                 /* If 'I' was greater than (or equal to) rsa->n, the operation
 930                  * will be equivalent to using 'I mod n'. However, the result of
 931                  * the verify will *always* be less than 'n' so we don't check
 932                  * for absolute equality, just congruency. */
 933                 if (!BN_sub(vrfy, vrfy, I)) goto err;
 934                 if (!BN_mod(vrfy, vrfy, rsa->n, ctx)) goto err;
 935                 if (BN_is_negative(vrfy))
 936                         if (!BN_add(vrfy, vrfy, rsa->n)) goto err;
 937                 if (!BN_is_zero(vrfy))
 938                         {
 939                         /* 'I' and 'vrfy' aren't congruent mod n. Don't leak
 940                          * miscalculated CRT output, just do a raw (slower)
 941                          * mod_exp and return that instead. */
 942
 943                         BIGNUM local_d;
 944                         BIGNUM *d = NULL;
 945
 946                         if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 947                                 {
 948                                 d = &local_d;
 949                                 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
 950                                 }
 951                         else
 952                                 d = rsa->d;
 953                         if (!rsa->meth->bn_mod_exp(r0,I,d,rsa->n,ctx,
 954                                                    rsa->_method_mod_n)) goto err;
 955                         }
 956                 }
 957         ret=1;
 958 err:
 959         BN_CTX_end(ctx);
 960         return(ret);
 961         }
 962
 963 static int RSA_eay_init(RSA *rsa)
 964         {
 965 #ifdef OPENSSL_FIPS
 966         if(FIPS_selftest_failed())
 967                 {
 968                 FIPSerr(FIPS_F_RSA_EAY_INIT,FIPS_R_FIPS_SELFTEST_FAILED);
 969                 return 0;
 970                 }
 971 #endif
 972         rsa->flags|=RSA_FLAG_CACHE_PUBLIC|RSA_FLAG_CACHE_PRIVATE;
 973         return(1);
 974         }
 975
 976 static int RSA_eay_finish(RSA *rsa)
 977         {
 978         if (rsa->_method_mod_n != NULL)
 979                 BN_MONT_CTX_free(rsa->_method_mod_n);
 980         if (rsa->_method_mod_p != NULL)
 981                 BN_MONT_CTX_free(rsa->_method_mod_p);
 982         if (rsa->_method_mod_q != NULL)
 983                 BN_MONT_CTX_free(rsa->_method_mod_q);
 984         return(1);
 985         }
 986
 987 #endif