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