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
 113
 114 #include "cryptlib.h"
 115 #include "internal/bn_int.h"
 116 #include <openssl/rsa.h>
 117 #include <openssl/rand.h>
 118
 119 #ifndef RSA_NULL
 120
 121 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
 122                 unsigned char *to, RSA *rsa,int padding);
 123 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
 124                 unsigned char *to, RSA *rsa,int padding);
 125 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
 126                 unsigned char *to, RSA *rsa,int padding);
 127 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
 128                 unsigned char *to, RSA *rsa,int padding);
 129 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *i, RSA *rsa, BN_CTX *ctx);
 130 static int RSA_eay_init(RSA *rsa);
 131 static int RSA_eay_finish(RSA *rsa);
 132 static RSA_METHOD rsa_pkcs1_eay_meth={
 133         "Eric Young's PKCS#1 RSA",
 134         RSA_eay_public_encrypt,
 135         RSA_eay_public_decrypt, /* signature verification */
 136         RSA_eay_private_encrypt, /* signing */
 137         RSA_eay_private_decrypt,
 138         RSA_eay_mod_exp,
 139         BN_mod_exp_mont, /* XXX probably we should not use Montgomery if  e == 3 */
 140         RSA_eay_init,
 141         RSA_eay_finish,
 142         RSA_FLAG_FIPS_METHOD, /* flags */
 143         NULL,
 144         0, /* rsa_sign */
 145         0, /* rsa_verify */
 146         NULL /* rsa_keygen */
 147         };
 148
 149 const RSA_METHOD *RSA_PKCS1_SSLeay(void)
 150         {
 151         return(&rsa_pkcs1_eay_meth);
 152         }
 153
 154 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
 155              unsigned char *to, RSA *rsa, int padding)
 156         {
 157         BIGNUM *f,*ret;
 158         int i,j,k,num=0,r= -1;
 159         unsigned char *buf=NULL;
 160         BN_CTX *ctx=NULL;
 161
 162         if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS)
 163                 {
 164                 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_MODULUS_TOO_LARGE);
 165                 return -1;
 166                 }
 167
 168         if (BN_ucmp(rsa->n, rsa->e) <= 0)
 169                 {
 170                 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
 171                 return -1;
 172                 }
 173
 174         /* for large moduli, enforce exponent limit */
 175         if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS)
 176                 {
 177                 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS)
 178                         {
 179                         RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
 180                         return -1;
 181                         }
 182                 }
 183
 184         if ((ctx=BN_CTX_new()) == NULL) goto err;
 185         BN_CTX_start(ctx);
 186         f = BN_CTX_get(ctx);
 187         ret = BN_CTX_get(ctx);
 188         num=BN_num_bytes(rsa->n);
 189         buf = OPENSSL_malloc(num);
 190         if (!f || !ret || !buf)
 191                 {
 192                 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,ERR_R_MALLOC_FAILURE);
 193                 goto err;
 194                 }
 195
 196         switch (padding)
 197                 {
 198         case RSA_PKCS1_PADDING:
 199                 i=RSA_padding_add_PKCS1_type_2(buf,num,from,flen);
 200                 break;
 201 #ifndef OPENSSL_NO_SHA
 202         case RSA_PKCS1_OAEP_PADDING:
 203                 i=RSA_padding_add_PKCS1_OAEP(buf,num,from,flen,NULL,0);
 204                 break;
 205 #endif
 206         case RSA_SSLV23_PADDING:
 207                 i=RSA_padding_add_SSLv23(buf,num,from,flen);
 208                 break;
 209         case RSA_NO_PADDING:
 210                 i=RSA_padding_add_none(buf,num,from,flen);
 211                 break;
 212         default:
 213                 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
 214                 goto err;
 215                 }
 216         if (i <= 0) goto err;
 217
 218         if (BN_bin2bn(buf,num,f) == NULL) goto err;
 219
 220         if (BN_ucmp(f, rsa->n) >= 0)
 221                 {
 222                 /* usually the padding functions would catch this */
 223                 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
 224                 goto err;
 225                 }
 226
 227         if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
 228                 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
 229                         goto err;
 230
 231         if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx,
 232                 rsa->_method_mod_n)) goto err;
 233
 234         /* put in leading 0 bytes if the number is less than the
 235          * length of the modulus */
 236         j=BN_num_bytes(ret);
 237         i=BN_bn2bin(ret,&(to[num-j]));
 238         for (k=0; k<(num-i); k++)
 239                 to[k]=0;
 240
 241         r=num;
 242 err:
 243         if (ctx != NULL)
 244                 {
 245                 BN_CTX_end(ctx);
 246                 BN_CTX_free(ctx);
 247                 }
 248         if (buf != NULL)
 249                 {
 250                 OPENSSL_cleanse(buf,num);
 251                 OPENSSL_free(buf);
 252                 }
 253         return(r);
 254         }
 255
 256 static BN_BLINDING *rsa_get_blinding(RSA *rsa, int *local, BN_CTX *ctx)
 257 {
 258         BN_BLINDING *ret;
 259         int got_write_lock = 0;
 260         CRYPTO_THREADID cur;
 261
 262         CRYPTO_r_lock(CRYPTO_LOCK_RSA);
 263
 264         if (rsa->blinding == NULL)
 265                 {
 266                 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
 267                 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
 268                 got_write_lock = 1;
 269
 270                 if (rsa->blinding == NULL)
 271                         rsa->blinding = RSA_setup_blinding(rsa, ctx);
 272                 }
 273
 274         ret = rsa->blinding;
 275         if (ret == NULL)
 276                 goto err;
 277
 278         CRYPTO_THREADID_current(&cur);
 279         if (!CRYPTO_THREADID_cmp(&cur, BN_BLINDING_thread_id(ret)))
 280                 {
 281                 /* rsa->blinding is ours! */
 282
 283                 *local = 1;
 284                 }
 285         else
 286                 {
 287                 /* resort to rsa->mt_blinding instead */
 288
 289                 /* instructs rsa_blinding_convert(), rsa_blinding_invert()
 290                  * that the BN_BLINDING is shared, meaning that accesses
 291                  * require locks, and that the blinding factor must be
 292                  * stored outside the BN_BLINDING
 293                  */
 294                 *local = 0;
 295
 296                 if (rsa->mt_blinding == NULL)
 297                         {
 298                         if (!got_write_lock)
 299                                 {
 300                                 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
 301                                 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
 302                                 got_write_lock = 1;
 303                                 }
 304
 305                         if (rsa->mt_blinding == NULL)
 306                                 rsa->mt_blinding = RSA_setup_blinding(rsa, ctx);
 307                         }
 308                 ret = rsa->mt_blinding;
 309                 }
 310
 311  err:
 312         if (got_write_lock)
 313                 CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
 314         else
 315                 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
 316         return ret;
 317 }
 318
 319 static int rsa_blinding_convert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
 320         BN_CTX *ctx)
 321         {
 322         if (unblind == NULL)
 323                 /* Local blinding: store the unblinding factor
 324                  * in BN_BLINDING. */
 325                 return BN_BLINDING_convert_ex(f, NULL, b, ctx);
 326         else
 327                 {
 328                 /* Shared blinding: store the unblinding factor
 329                  * outside BN_BLINDING. */
 330                 int ret;
 331                 CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING);
 332                 ret = BN_BLINDING_convert_ex(f, unblind, b, ctx);
 333                 CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING);
 334                 return ret;
 335                 }
 336         }
 337
 338 static int rsa_blinding_invert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
 339         BN_CTX *ctx)
 340         {
 341         /* For local blinding, unblind is set to NULL, and BN_BLINDING_invert_ex
 342          * will use the unblinding factor stored in BN_BLINDING.
 343          * If BN_BLINDING is shared between threads, unblind must be non-null:
 344          * BN_BLINDING_invert_ex will then use the local unblinding factor,
 345          * and will only read the modulus from BN_BLINDING.
 346          * In both cases it's safe to access the blinding without a lock.
 347          */
 348         return BN_BLINDING_invert_ex(f, unblind, b, ctx);
 349         }
 350
 351 /* signing */
 352 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
 353              unsigned char *to, RSA *rsa, int padding)
 354         {
 355         BIGNUM *f, *ret, *res;
 356         int i,j,k,num=0,r= -1;
 357         unsigned char *buf=NULL;
 358         BN_CTX *ctx=NULL;
 359         int local_blinding = 0;
 360         /* Used only if the blinding structure is shared. A non-NULL unblind
 361          * instructs rsa_blinding_convert() and rsa_blinding_invert() to store
 362          * the unblinding factor outside the blinding structure. */
 363         BIGNUM *unblind = NULL;
 364         BN_BLINDING *blinding = NULL;
 365
 366         if ((ctx=BN_CTX_new()) == NULL) goto err;
 367         BN_CTX_start(ctx);
 368         f   = BN_CTX_get(ctx);
 369         ret = BN_CTX_get(ctx);
 370         num = BN_num_bytes(rsa->n);
 371         buf = OPENSSL_malloc(num);
 372         if(!f || !ret || !buf)
 373                 {
 374                 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);
 375                 goto err;
 376                 }
 377
 378         switch (padding)
 379                 {
 380         case RSA_PKCS1_PADDING:
 381                 i=RSA_padding_add_PKCS1_type_1(buf,num,from,flen);
 382                 break;
 383         case RSA_X931_PADDING:
 384                 i=RSA_padding_add_X931(buf,num,from,flen);
 385                 break;
 386         case RSA_NO_PADDING:
 387                 i=RSA_padding_add_none(buf,num,from,flen);
 388                 break;
 389         case RSA_SSLV23_PADDING:
 390         default:
 391                 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
 392                 goto err;
 393                 }
 394         if (i <= 0) goto err;
 395
 396         if (BN_bin2bn(buf,num,f) == NULL) goto err;
 397
 398         if (BN_ucmp(f, rsa->n) >= 0)
 399                 {
 400                 /* usually the padding functions would catch this */
 401                 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
 402                 goto err;
 403                 }
 404
 405         if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
 406                 {
 407                 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
 408                 if (blinding == NULL)
 409                         {
 410                         RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);
 411                         goto err;
 412                         }
 413                 }
 414
 415         if (blinding != NULL)
 416                 {
 417                 if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL))
 418                         {
 419                         RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);
 420                         goto err;
 421                         }
 422                 if (!rsa_blinding_convert(blinding, f, unblind, ctx))
 423                         goto err;
 424                 }
 425
 426         if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
 427                 ((rsa->p != NULL) &&
 428                 (rsa->q != NULL) &&
 429                 (rsa->dmp1 != NULL) &&
 430                 (rsa->dmq1 != NULL) &&
 431                 (rsa->iqmp != NULL)) )
 432                 {
 433                 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err;
 434                 }
 435         else
 436                 {
 437                 BIGNUM *d = NULL, *local_d = NULL;
 438
 439                 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 440                         {
 441                         local_d = d = BN_new();
 442                         if(!d)
 443                                 {
 444                                 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);
 445                                 goto err;
 446                                 }
 447                         BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
 448                         }
 449                 else
 450                         d= rsa->d;
 451
 452                 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
 453                         if(!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
 454                                 {
 455                                 if(local_d) BN_free(local_d);
 456                                 goto err;
 457                                 }
 458
 459                 if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx,
 460                                 rsa->_method_mod_n))
 461                         {
 462                         if(local_d) BN_free(local_d);
 463                         goto err;
 464                         }
 465                 if(local_d) BN_free(local_d);
 466                 }
 467
 468         if (blinding)
 469                 if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
 470                         goto err;
 471
 472         if (padding == RSA_X931_PADDING)
 473                 {
 474                 BN_sub(f, rsa->n, ret);
 475                 if (BN_cmp(ret, f) > 0)
 476                         res = f;
 477                 else
 478                         res = ret;
 479                 }
 480         else
 481                 res = ret;
 482
 483         /* put in leading 0 bytes if the number is less than the
 484          * length of the modulus */
 485         j=BN_num_bytes(res);
 486         i=BN_bn2bin(res,&(to[num-j]));
 487         for (k=0; k<(num-i); k++)
 488                 to[k]=0;
 489
 490         r=num;
 491 err:
 492         if (ctx != NULL)
 493                 {
 494                 BN_CTX_end(ctx);
 495                 BN_CTX_free(ctx);
 496                 }
 497         if (buf != NULL)
 498                 {
 499                 OPENSSL_cleanse(buf,num);
 500                 OPENSSL_free(buf);
 501                 }
 502         return(r);
 503         }
 504
 505 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
 506              unsigned char *to, RSA *rsa, int padding)
 507         {
 508         BIGNUM *f, *ret;
 509         int j,num=0,r= -1;
 510         unsigned char *p;
 511         unsigned char *buf=NULL;
 512         BN_CTX *ctx=NULL;
 513         int local_blinding = 0;
 514         /* Used only if the blinding structure is shared. A non-NULL unblind
 515          * instructs rsa_blinding_convert() and rsa_blinding_invert() to store
 516          * the unblinding factor outside the blinding structure. */
 517         BIGNUM *unblind = NULL;
 518         BN_BLINDING *blinding = NULL;
 519
 520         if((ctx = BN_CTX_new()) == NULL) goto err;
 521         BN_CTX_start(ctx);
 522         f   = BN_CTX_get(ctx);
 523         ret = BN_CTX_get(ctx);
 524         num = BN_num_bytes(rsa->n);
 525         buf = OPENSSL_malloc(num);
 526         if(!f || !ret || !buf)
 527                 {
 528                 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
 529                 goto err;
 530                 }
 531
 532         /* This check was for equality but PGP does evil things
 533          * and chops off the top '0' bytes */
 534         if (flen > num)
 535                 {
 536                 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
 537                 goto err;
 538                 }
 539
 540         /* make data into a big number */
 541         if (BN_bin2bn(from,(int)flen,f) == NULL) goto err;
 542
 543         if (BN_ucmp(f, rsa->n) >= 0)
 544                 {
 545                 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
 546                 goto err;
 547                 }
 548
 549         if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
 550                 {
 551                 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
 552                 if (blinding == NULL)
 553                         {
 554                         RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);
 555                         goto err;
 556                         }
 557                 }
 558
 559         if (blinding != NULL)
 560                 {
 561                 if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL))
 562                         {
 563                         RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
 564                         goto err;
 565                         }
 566                 if (!rsa_blinding_convert(blinding, f, unblind, ctx))
 567                         goto err;
 568                 }
 569
 570         /* do the decrypt */
 571         if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
 572                 ((rsa->p != NULL) &&
 573                 (rsa->q != NULL) &&
 574                 (rsa->dmp1 != NULL) &&
 575                 (rsa->dmq1 != NULL) &&
 576                 (rsa->iqmp != NULL)) )
 577                 {
 578                 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err;
 579                 }
 580         else
 581                 {
 582                 BIGNUM *d = NULL, *local_d = NULL;
 583
 584                 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 585                         {
 586                         local_d = d = BN_new();
 587                         if(!d)
 588                                 {
 589                                 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
 590                                 goto err;
 591                                 }
 592                         BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
 593                         }
 594                 else
 595                         d = rsa->d;
 596
 597                 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
 598                         if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
 599                                 {
 600                                 if(local_d) BN_free(local_d);
 601                                 goto err;
 602                                 }
 603                 if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx,
 604                                 rsa->_method_mod_n))
 605                         {
 606                         if(local_d) BN_free(local_d);
 607                         goto err;
 608                         }
 609                 if(local_d) BN_free(local_d);
 610                 }
 611
 612         if (blinding)
 613                 if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
 614                         goto err;
 615
 616         p=buf;
 617         j=BN_bn2bin(ret,p); /* j is only used with no-padding mode */
 618
 619         switch (padding)
 620                 {
 621         case RSA_PKCS1_PADDING:
 622                 r=RSA_padding_check_PKCS1_type_2(to,num,buf,j,num);
 623                 break;
 624 #ifndef OPENSSL_NO_SHA
 625         case RSA_PKCS1_OAEP_PADDING:
 626                 r=RSA_padding_check_PKCS1_OAEP(to,num,buf,j,num,NULL,0);
 627                 break;
 628 #endif
 629         case RSA_SSLV23_PADDING:
 630                 r=RSA_padding_check_SSLv23(to,num,buf,j,num);
 631                 break;
 632         case RSA_NO_PADDING:
 633                 r=RSA_padding_check_none(to,num,buf,j,num);
 634                 break;
 635         default:
 636                 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
 637                 goto err;
 638                 }
 639         if (r < 0)
 640                 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
 641
 642 err:
 643         if (ctx != NULL)
 644                 {
 645                 BN_CTX_end(ctx);
 646                 BN_CTX_free(ctx);
 647                 }
 648         if (buf != NULL)
 649                 {
 650                 OPENSSL_cleanse(buf,num);
 651                 OPENSSL_free(buf);
 652                 }
 653         return(r);
 654         }
 655
 656 /* signature verification */
 657 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
 658              unsigned char *to, RSA *rsa, int padding)
 659         {
 660         BIGNUM *f,*ret;
 661         int i,num=0,r= -1;
 662         unsigned char *p;
 663         unsigned char *buf=NULL;
 664         BN_CTX *ctx=NULL;
 665
 666         if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS)
 667                 {
 668                 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE);
 669                 return -1;
 670                 }
 671
 672         if (BN_ucmp(rsa->n, rsa->e) <= 0)
 673                 {
 674                 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
 675                 return -1;
 676                 }
 677
 678         /* for large moduli, enforce exponent limit */
 679         if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS)
 680                 {
 681                 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS)
 682                         {
 683                         RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
 684                         return -1;
 685                         }
 686                 }
 687
 688         if((ctx = BN_CTX_new()) == NULL) goto err;
 689         BN_CTX_start(ctx);
 690         f = BN_CTX_get(ctx);
 691         ret = BN_CTX_get(ctx);
 692         num=BN_num_bytes(rsa->n);
 693         buf = OPENSSL_malloc(num);
 694         if(!f || !ret || !buf)
 695                 {
 696                 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE);
 697                 goto err;
 698                 }
 699
 700         /* This check was for equality but PGP does evil things
 701          * and chops off the top '0' bytes */
 702         if (flen > num)
 703                 {
 704                 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
 705                 goto err;
 706                 }
 707
 708         if (BN_bin2bn(from,flen,f) == NULL) goto err;
 709
 710         if (BN_ucmp(f, rsa->n) >= 0)
 711                 {
 712                 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
 713                 goto err;
 714                 }
 715
 716         if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
 717                 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
 718                         goto err;
 719
 720         if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx,
 721                 rsa->_method_mod_n)) goto err;
 722
 723         if ((padding == RSA_X931_PADDING) && ((bn_get_words(ret)[0] & 0xf) != 12))
 724                 if (!BN_sub(ret, rsa->n, ret)) goto err;
 725
 726         p=buf;
 727         i=BN_bn2bin(ret,p);
 728
 729         switch (padding)
 730                 {
 731         case RSA_PKCS1_PADDING:
 732                 r=RSA_padding_check_PKCS1_type_1(to,num,buf,i,num);
 733                 break;
 734         case RSA_X931_PADDING:
 735                 r=RSA_padding_check_X931(to,num,buf,i,num);
 736                 break;
 737         case RSA_NO_PADDING:
 738                 r=RSA_padding_check_none(to,num,buf,i,num);
 739                 break;
 740         default:
 741                 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
 742                 goto err;
 743                 }
 744         if (r < 0)
 745                 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
 746
 747 err:
 748         if (ctx != NULL)
 749                 {
 750                 BN_CTX_end(ctx);
 751                 BN_CTX_free(ctx);
 752                 }
 753         if (buf != NULL)
 754                 {
 755                 OPENSSL_cleanse(buf,num);
 756                 OPENSSL_free(buf);
 757                 }
 758         return(r);
 759         }
 760
 761 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
 762         {
 763         BIGNUM *r1,*m1,*vrfy;
 764         BIGNUM *local_dmp1, *local_dmq1, *local_c, *local_r1;
 765         BIGNUM *dmp1,*dmq1,*c,*pr1;
 766         int ret=0;
 767
 768
 769         local_dmp1 = BN_new();
 770         local_dmq1 = BN_new();
 771         local_c = BN_new();
 772         local_r1 = BN_new();
 773         if(!local_dmp1 || !local_dmq1 || !local_c || !local_r1)
 774                 goto err;
 775
 776         BN_CTX_start(ctx);
 777         r1 = BN_CTX_get(ctx);
 778         m1 = BN_CTX_get(ctx);
 779         vrfy = BN_CTX_get(ctx);
 780
 781         {
 782                 BIGNUM *local_p = NULL, *local_q = NULL;
 783                 BIGNUM *p = NULL, *q = NULL;
 784
 785                 /* Make sure BN_mod_inverse in Montgomery intialization uses the
 786                  * BN_FLG_CONSTTIME flag (unless RSA_FLAG_NO_CONSTTIME is set)
 787                  */
 788                 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 789                         {
 790                         local_p = p = BN_new();
 791                         if(!p) goto err;
 792                         BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
 793
 794                         local_q = q = BN_new();
 795                         if(!q)
 796                                 {
 797                                 BN_free(local_p);
 798                                 goto err;
 799                                 }
 800                         BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME);
 801                         }
 802                 else
 803                         {
 804                         p = rsa->p;
 805                         q = rsa->q;
 806                         }
 807
 808                 if (rsa->flags & RSA_FLAG_CACHE_PRIVATE)
 809                         {
 810                         if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_p, CRYPTO_LOCK_RSA, p, ctx) || !BN_MONT_CTX_set_locked(&rsa->_method_mod_q, CRYPTO_LOCK_RSA, q, ctx))
 811                                 {
 812                                 if(local_p) BN_free(local_p);
 813                                 if(local_q) BN_free(local_q);
 814                                 goto err;
 815                                 }
 816                         }
 817                 if(local_p) BN_free(local_p);
 818                 if(local_q) BN_free(local_q);
 819         }
 820
 821         if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
 822                 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
 823                         goto err;
 824
 825         /* compute I mod q */
 826         if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 827                 {
 828                 c = local_c;
 829                 BN_with_flags(c, I, BN_FLG_CONSTTIME);
 830                 if (!BN_mod(r1,c,rsa->q,ctx)) goto err;
 831                 }
 832         else
 833                 {
 834                 if (!BN_mod(r1,I,rsa->q,ctx)) goto err;
 835                 }
 836
 837         /* compute r1^dmq1 mod q */
 838         if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 839                 {
 840                 dmq1 = local_dmq1;
 841                 BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
 842                 }
 843         else
 844                 dmq1 = rsa->dmq1;
 845         if (!rsa->meth->bn_mod_exp(m1,r1,dmq1,rsa->q,ctx,
 846                 rsa->_method_mod_q)) goto err;
 847
 848         /* compute I mod p */
 849         if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 850                 {
 851                 c = local_c;
 852                 BN_with_flags(c, I, BN_FLG_CONSTTIME);
 853                 if (!BN_mod(r1,c,rsa->p,ctx)) goto err;
 854                 }
 855         else
 856                 {
 857                 if (!BN_mod(r1,I,rsa->p,ctx)) goto err;
 858                 }
 859
 860         /* compute r1^dmp1 mod p */
 861         if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 862                 {
 863                 dmp1 = local_dmp1;
 864                 BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
 865                 }
 866         else
 867                 dmp1 = rsa->dmp1;
 868         if (!rsa->meth->bn_mod_exp(r0,r1,dmp1,rsa->p,ctx,
 869                 rsa->_method_mod_p)) goto err;
 870
 871         if (!BN_sub(r0,r0,m1)) goto err;
 872         /* This will help stop the size of r0 increasing, which does
 873          * affect the multiply if it optimised for a power of 2 size */
 874         if (BN_is_negative(r0))
 875                 if (!BN_add(r0,r0,rsa->p)) goto err;
 876
 877         if (!BN_mul(r1,r0,rsa->iqmp,ctx)) goto err;
 878
 879         /* Turn BN_FLG_CONSTTIME flag on before division operation */
 880         if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 881                 {
 882                 pr1 = local_r1;
 883                 BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
 884                 }
 885         else
 886                 pr1 = r1;
 887         if (!BN_mod(r0,pr1,rsa->p,ctx)) goto err;
 888
 889         /* If p < q it is occasionally possible for the correction of
 890          * adding 'p' if r0 is negative above to leave the result still
 891          * negative. This can break the private key operations: the following
 892          * second correction should *always* correct this rare occurrence.
 893          * This will *never* happen with OpenSSL generated keys because
 894          * they ensure p > q [steve]
 895          */
 896         if (BN_is_negative(r0))
 897                 if (!BN_add(r0,r0,rsa->p)) goto err;
 898         if (!BN_mul(r1,r0,rsa->q,ctx)) goto err;
 899         if (!BN_add(r0,r1,m1)) goto err;
 900
 901         if (rsa->e && rsa->n)
 902                 {
 903                 if (!rsa->meth->bn_mod_exp(vrfy,r0,rsa->e,rsa->n,ctx,rsa->_method_mod_n)) goto err;
 904                 /* If 'I' was greater than (or equal to) rsa->n, the operation
 905                  * will be equivalent to using 'I mod n'. However, the result of
 906                  * the verify will *always* be less than 'n' so we don't check
 907                  * for absolute equality, just congruency. */
 908                 if (!BN_sub(vrfy, vrfy, I)) goto err;
 909                 if (!BN_mod(vrfy, vrfy, rsa->n, ctx)) goto err;
 910                 if (BN_is_negative(vrfy))
 911                         if (!BN_add(vrfy, vrfy, rsa->n)) goto err;
 912                 if (!BN_is_zero(vrfy))
 913                         {
 914                         /* 'I' and 'vrfy' aren't congruent mod n. Don't leak
 915                          * miscalculated CRT output, just do a raw (slower)
 916                          * mod_exp and return that instead. */
 917
 918                         BIGNUM *local_d = NULL;
 919                         BIGNUM *d = NULL;
 920
 921                         if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 922                                 {
 923                                 local_d = d = BN_new();
 924                                 if(!d) goto err;
 925                                 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
 926                                 }
 927                         else
 928                                 d = rsa->d;
 929                         if (!rsa->meth->bn_mod_exp(r0,I,d,rsa->n,ctx,
 930                                                    rsa->_method_mod_n))
 931                                 {
 932                                 if(local_d) BN_free(local_d);
 933                                 goto err;
 934                                 }
 935
 936                         if(local_d) BN_free(local_d);
 937                         }
 938                 }
 939         ret=1;
 940 err:
 941         if(local_dmp1) BN_free(local_dmp1);
 942         if(local_dmq1) BN_free(local_dmq1);
 943         if(local_c) BN_free(local_c);
 944         if(local_r1) BN_free(local_r1);
 945         BN_CTX_end(ctx);
 946         return(ret);
 947         }
 948
 949 static int RSA_eay_init(RSA *rsa)
 950         {
 951         rsa->flags|=RSA_FLAG_CACHE_PUBLIC|RSA_FLAG_CACHE_PRIVATE;
 952         return(1);
 953         }
 954
 955 static int RSA_eay_finish(RSA *rsa)
 956         {
 957         if (rsa->_method_mod_n != NULL)
 958                 BN_MONT_CTX_free(rsa->_method_mod_n);
 959         if (rsa->_method_mod_p != NULL)
 960                 BN_MONT_CTX_free(rsa->_method_mod_p);
 961         if (rsa->_method_mod_q != NULL)
 962                 BN_MONT_CTX_free(rsa->_method_mod_q);
 963         return(1);
 964         }
 965
 966 #endif