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 #include <stdio.h>
  60 #include "cryptlib.h"
  61 #include <openssl/bn.h>
  62 #include <openssl/rsa.h>
  63 #include <openssl/rand.h>
  64 #include <openssl/engine.h>
  65
  66 #ifndef RSA_NULL
  67
  68 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
  69                 unsigned char *to, RSA *rsa,int padding);
  70 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
  71                 unsigned char *to, RSA *rsa,int padding);
  72 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
  73                 unsigned char *to, RSA *rsa,int padding);
  74 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
  75                 unsigned char *to, RSA *rsa,int padding);
  76 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *i, RSA *rsa);
  77 static int RSA_eay_init(RSA *rsa);
  78 static int RSA_eay_finish(RSA *rsa);
  79 static RSA_METHOD rsa_pkcs1_eay_meth={
  80         "Eric Young's PKCS#1 RSA",
  81         RSA_eay_public_encrypt,
  82         RSA_eay_public_decrypt,
  83         RSA_eay_private_encrypt,
  84         RSA_eay_private_decrypt,
  85         RSA_eay_mod_exp,
  86         BN_mod_exp_mont, /* XXX probably we should not use Montgomery if  e == 3 */
  87         RSA_eay_init,
  88         RSA_eay_finish,
  89         0,
  90         NULL,
  91         };
  92
  93 const RSA_METHOD *RSA_PKCS1_SSLeay(void)
  94         {
  95         return(&rsa_pkcs1_eay_meth);
  96         }
  97
  98 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
  99              unsigned char *to, RSA *rsa, int padding)
 100         {
 101         const RSA_METHOD *meth;
 102         BIGNUM f,ret;
 103         int i,j,k,num=0,r= -1;
 104         unsigned char *buf=NULL;
 105         BN_CTX *ctx=NULL;
 106
 107         meth = ENGINE_get_RSA(rsa->engine);
 108         BN_init(&f);
 109         BN_init(&ret);
 110         if ((ctx=BN_CTX_new()) == NULL) goto err;
 111         num=BN_num_bytes(rsa->n);
 112         if ((buf=(unsigned char *)OPENSSL_malloc(num)) == NULL)
 113                 {
 114                 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,ERR_R_MALLOC_FAILURE);
 115                 goto err;
 116                 }
 117
 118         switch (padding)
 119                 {
 120         case RSA_PKCS1_PADDING:
 121                 i=RSA_padding_add_PKCS1_type_2(buf,num,from,flen);
 122                 break;
 123 #ifndef OPENSSL_NO_SHA
 124         case RSA_PKCS1_OAEP_PADDING:
 125                 i=RSA_padding_add_PKCS1_OAEP(buf,num,from,flen,NULL,0);
 126                 break;
 127 #endif
 128         case RSA_SSLV23_PADDING:
 129                 i=RSA_padding_add_SSLv23(buf,num,from,flen);
 130                 break;
 131         case RSA_NO_PADDING:
 132                 i=RSA_padding_add_none(buf,num,from,flen);
 133                 break;
 134         default:
 135                 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
 136                 goto err;
 137                 }
 138         if (i <= 0) goto err;
 139
 140         if (BN_bin2bn(buf,num,&f) == NULL) goto err;
 141
 142         if ((rsa->_method_mod_n == NULL) && (rsa->flags & RSA_FLAG_CACHE_PUBLIC))
 143                 {
 144                 BN_MONT_CTX* bn_mont_ctx;
 145                 if ((bn_mont_ctx=BN_MONT_CTX_new()) == NULL)
 146                         goto err;
 147                 if (!BN_MONT_CTX_set(bn_mont_ctx,rsa->n,ctx))
 148                         {
 149                         BN_MONT_CTX_free(bn_mont_ctx);
 150                         goto err;
 151                         }
 152                 if (rsa->_method_mod_n == NULL) /* other thread may have finished first */
 153                         {
 154                         CRYPTO_w_lock(CRYPTO_LOCK_RSA);
 155                         if (rsa->_method_mod_n == NULL)
 156                                 {
 157                                 rsa->_method_mod_n = bn_mont_ctx;
 158                                 bn_mont_ctx = NULL;
 159                                 }
 160                         CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
 161                         }
 162                 if (bn_mont_ctx)
 163                         BN_MONT_CTX_free(bn_mont_ctx);
 164                 }
 165
 166         if (!meth->bn_mod_exp(&ret,&f,rsa->e,rsa->n,ctx,
 167                 rsa->_method_mod_n)) goto err;
 168
 169         /* put in leading 0 bytes if the number is less than the
 170          * length of the modulus */
 171         j=BN_num_bytes(&ret);
 172         i=BN_bn2bin(&ret,&(to[num-j]));
 173         for (k=0; k<(num-i); k++)
 174                 to[k]=0;
 175
 176         r=num;
 177 err:
 178         if (ctx != NULL) BN_CTX_free(ctx);
 179         BN_clear_free(&f);
 180         BN_clear_free(&ret);
 181         if (buf != NULL)
 182                 {
 183                 memset(buf,0,num);
 184                 OPENSSL_free(buf);
 185                 }
 186         return(r);
 187         }
 188
 189 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
 190              unsigned char *to, RSA *rsa, int padding)
 191         {
 192         const RSA_METHOD *meth;
 193         BIGNUM f,ret;
 194         int i,j,k,num=0,r= -1;
 195         unsigned char *buf=NULL;
 196         BN_CTX *ctx=NULL;
 197
 198         meth = ENGINE_get_RSA(rsa->engine);
 199         BN_init(&f);
 200         BN_init(&ret);
 201
 202         if ((ctx=BN_CTX_new()) == NULL) goto err;
 203         num=BN_num_bytes(rsa->n);
 204         if ((buf=(unsigned char *)OPENSSL_malloc(num)) == NULL)
 205                 {
 206                 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);
 207                 goto err;
 208                 }
 209
 210         switch (padding)
 211                 {
 212         case RSA_PKCS1_PADDING:
 213                 i=RSA_padding_add_PKCS1_type_1(buf,num,from,flen);
 214                 break;
 215         case RSA_NO_PADDING:
 216                 i=RSA_padding_add_none(buf,num,from,flen);
 217                 break;
 218         case RSA_SSLV23_PADDING:
 219         default:
 220                 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
 221                 goto err;
 222                 }
 223         if (i <= 0) goto err;
 224
 225         if (BN_bin2bn(buf,num,&f) == NULL) goto err;
 226
 227         if ((rsa->flags & RSA_FLAG_BLINDING) && (rsa->blinding == NULL))
 228                 RSA_blinding_on(rsa,ctx);
 229         if (rsa->flags & RSA_FLAG_BLINDING)
 230                 if (!BN_BLINDING_convert(&f,rsa->blinding,ctx)) goto err;
 231
 232         if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
 233                 ((rsa->p != NULL) &&
 234                 (rsa->q != NULL) &&
 235                 (rsa->dmp1 != NULL) &&
 236                 (rsa->dmq1 != NULL) &&
 237                 (rsa->iqmp != NULL)) )
 238                 { if (!meth->rsa_mod_exp(&ret,&f,rsa)) goto err; }
 239         else
 240                 {
 241                 if (!meth->bn_mod_exp(&ret,&f,rsa->d,rsa->n,ctx,NULL)) goto err;
 242                 }
 243
 244         if (rsa->flags & RSA_FLAG_BLINDING)
 245                 if (!BN_BLINDING_invert(&ret,rsa->blinding,ctx)) goto err;
 246
 247         /* put in leading 0 bytes if the number is less than the
 248          * length of the modulus */
 249         j=BN_num_bytes(&ret);
 250         i=BN_bn2bin(&ret,&(to[num-j]));
 251         for (k=0; k<(num-i); k++)
 252                 to[k]=0;
 253
 254         r=num;
 255 err:
 256         if (ctx != NULL) BN_CTX_free(ctx);
 257         BN_clear_free(&ret);
 258         BN_clear_free(&f);
 259         if (buf != NULL)
 260                 {
 261                 memset(buf,0,num);
 262                 OPENSSL_free(buf);
 263                 }
 264         return(r);
 265         }
 266
 267 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
 268              unsigned char *to, RSA *rsa, int padding)
 269         {
 270         const RSA_METHOD *meth;
 271         BIGNUM f,ret;
 272         int j,num=0,r= -1;
 273         unsigned char *p;
 274         unsigned char *buf=NULL;
 275         BN_CTX *ctx=NULL;
 276
 277         meth = ENGINE_get_RSA(rsa->engine);
 278         BN_init(&f);
 279         BN_init(&ret);
 280         ctx=BN_CTX_new();
 281         if (ctx == NULL) goto err;
 282
 283         num=BN_num_bytes(rsa->n);
 284
 285         if ((buf=(unsigned char *)OPENSSL_malloc(num)) == NULL)
 286                 {
 287                 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
 288                 goto err;
 289                 }
 290
 291         /* This check was for equality but PGP does evil things
 292          * and chops off the top '0' bytes */
 293         if (flen > num)
 294                 {
 295                 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
 296                 goto err;
 297                 }
 298
 299         /* make data into a big number */
 300         if (BN_bin2bn(from,(int)flen,&f) == NULL) goto err;
 301
 302         if ((rsa->flags & RSA_FLAG_BLINDING) && (rsa->blinding == NULL))
 303                 RSA_blinding_on(rsa,ctx);
 304         if (rsa->flags & RSA_FLAG_BLINDING)
 305                 if (!BN_BLINDING_convert(&f,rsa->blinding,ctx)) goto err;
 306
 307         /* do the decrypt */
 308         if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
 309                 ((rsa->p != NULL) &&
 310                 (rsa->q != NULL) &&
 311                 (rsa->dmp1 != NULL) &&
 312                 (rsa->dmq1 != NULL) &&
 313                 (rsa->iqmp != NULL)) )
 314                 { if (!meth->rsa_mod_exp(&ret,&f,rsa)) goto err; }
 315         else
 316                 {
 317                 if (!meth->bn_mod_exp(&ret,&f,rsa->d,rsa->n,ctx,NULL))
 318                         goto err;
 319                 }
 320
 321         if (rsa->flags & RSA_FLAG_BLINDING)
 322                 if (!BN_BLINDING_invert(&ret,rsa->blinding,ctx)) goto err;
 323
 324         p=buf;
 325         j=BN_bn2bin(&ret,p); /* j is only used with no-padding mode */
 326
 327         switch (padding)
 328                 {
 329         case RSA_PKCS1_PADDING:
 330                 r=RSA_padding_check_PKCS1_type_2(to,num,buf,j,num);
 331                 break;
 332 #ifndef OPENSSL_NO_SHA
 333         case RSA_PKCS1_OAEP_PADDING:
 334                 r=RSA_padding_check_PKCS1_OAEP(to,num,buf,j,num,NULL,0);
 335                 break;
 336 #endif
 337         case RSA_SSLV23_PADDING:
 338                 r=RSA_padding_check_SSLv23(to,num,buf,j,num);
 339                 break;
 340         case RSA_NO_PADDING:
 341                 r=RSA_padding_check_none(to,num,buf,j,num);
 342                 break;
 343         default:
 344                 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
 345                 goto err;
 346                 }
 347         if (r < 0)
 348                 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
 349
 350 err:
 351         if (ctx != NULL) BN_CTX_free(ctx);
 352         BN_clear_free(&f);
 353         BN_clear_free(&ret);
 354         if (buf != NULL)
 355                 {
 356                 memset(buf,0,num);
 357                 OPENSSL_free(buf);
 358                 }
 359         return(r);
 360         }
 361
 362 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
 363              unsigned char *to, RSA *rsa, int padding)
 364         {
 365         const RSA_METHOD *meth;
 366         BIGNUM f,ret;
 367         int i,num=0,r= -1;
 368         unsigned char *p;
 369         unsigned char *buf=NULL;
 370         BN_CTX *ctx=NULL;
 371
 372         meth = ENGINE_get_RSA(rsa->engine);
 373         BN_init(&f);
 374         BN_init(&ret);
 375         ctx=BN_CTX_new();
 376         if (ctx == NULL) goto err;
 377
 378         num=BN_num_bytes(rsa->n);
 379         buf=(unsigned char *)OPENSSL_malloc(num);
 380         if (buf == NULL)
 381                 {
 382                 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE);
 383                 goto err;
 384                 }
 385
 386         /* This check was for equality but PGP does evil things
 387          * and chops off the top '0' bytes */
 388         if (flen > num)
 389                 {
 390                 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
 391                 goto err;
 392                 }
 393
 394         if (BN_bin2bn(from,flen,&f) == NULL) goto err;
 395         /* do the decrypt */
 396         if ((rsa->_method_mod_n == NULL) && (rsa->flags & RSA_FLAG_CACHE_PUBLIC))
 397                 {
 398                 BN_MONT_CTX* bn_mont_ctx;
 399                 if ((bn_mont_ctx=BN_MONT_CTX_new()) == NULL)
 400                         goto err;
 401                 if (!BN_MONT_CTX_set(bn_mont_ctx,rsa->n,ctx))
 402                         {
 403                         BN_MONT_CTX_free(bn_mont_ctx);
 404                         goto err;
 405                         }
 406                 if (rsa->_method_mod_n == NULL) /* other thread may have finished first */
 407                         {
 408                         CRYPTO_w_lock(CRYPTO_LOCK_RSA);
 409                         if (rsa->_method_mod_n == NULL)
 410                                 {
 411                                 rsa->_method_mod_n = bn_mont_ctx;
 412                                 bn_mont_ctx = NULL;
 413                                 }
 414                         CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
 415                         }
 416                 if (bn_mont_ctx)
 417                         BN_MONT_CTX_free(bn_mont_ctx);
 418                 }
 419
 420         if (!meth->bn_mod_exp(&ret,&f,rsa->e,rsa->n,ctx,
 421                 rsa->_method_mod_n)) goto err;
 422
 423         p=buf;
 424         i=BN_bn2bin(&ret,p);
 425
 426         switch (padding)
 427                 {
 428         case RSA_PKCS1_PADDING:
 429                 r=RSA_padding_check_PKCS1_type_1(to,num,buf,i,num);
 430                 break;
 431         case RSA_NO_PADDING:
 432                 r=RSA_padding_check_none(to,num,buf,i,num);
 433                 break;
 434         default:
 435                 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
 436                 goto err;
 437                 }
 438         if (r < 0)
 439                 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
 440
 441 err:
 442         if (ctx != NULL) BN_CTX_free(ctx);
 443         BN_clear_free(&f);
 444         BN_clear_free(&ret);
 445         if (buf != NULL)
 446                 {
 447                 memset(buf,0,num);
 448                 OPENSSL_free(buf);
 449                 }
 450         return(r);
 451         }
 452
 453 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa)
 454         {
 455         const RSA_METHOD *meth;
 456         BIGNUM r1,m1,vrfy;
 457         int ret=0;
 458         BN_CTX *ctx;
 459
 460         meth = ENGINE_get_RSA(rsa->engine);
 461         if ((ctx=BN_CTX_new()) == NULL) goto err;
 462         BN_init(&m1);
 463         BN_init(&r1);
 464         BN_init(&vrfy);
 465
 466         if (rsa->flags & RSA_FLAG_CACHE_PRIVATE)
 467                 {
 468                 if (rsa->_method_mod_p == NULL)
 469                         {
 470                         BN_MONT_CTX* bn_mont_ctx;
 471                         if ((bn_mont_ctx=BN_MONT_CTX_new()) == NULL)
 472                                 goto err;
 473                         if (!BN_MONT_CTX_set(bn_mont_ctx,rsa->p,ctx))
 474                                 {
 475                                 BN_MONT_CTX_free(bn_mont_ctx);
 476                                 goto err;
 477                                 }
 478                         if (rsa->_method_mod_p == NULL) /* other thread may have finished first */
 479                                 {
 480                                 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
 481                                 if (rsa->_method_mod_p == NULL)
 482                                         {
 483                                         rsa->_method_mod_p = bn_mont_ctx;
 484                                         bn_mont_ctx = NULL;
 485                                         }
 486                                 CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
 487                                 }
 488                         if (bn_mont_ctx)
 489                                 BN_MONT_CTX_free(bn_mont_ctx);
 490                         }
 491
 492                 if (rsa->_method_mod_q == NULL)
 493                         {
 494                         BN_MONT_CTX* bn_mont_ctx;
 495                         if ((bn_mont_ctx=BN_MONT_CTX_new()) == NULL)
 496                                 goto err;
 497                         if (!BN_MONT_CTX_set(bn_mont_ctx,rsa->q,ctx))
 498                                 {
 499                                 BN_MONT_CTX_free(bn_mont_ctx);
 500                                 goto err;
 501                                 }
 502                         if (rsa->_method_mod_q == NULL) /* other thread may have finished first */
 503                                 {
 504                                 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
 505                                 if (rsa->_method_mod_q == NULL)
 506                                         {
 507                                         rsa->_method_mod_q = bn_mont_ctx;
 508                                         bn_mont_ctx = NULL;
 509                                         }
 510                                 CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
 511                                 }
 512                         if (bn_mont_ctx)
 513                                 BN_MONT_CTX_free(bn_mont_ctx);
 514                         }
 515                 }
 516
 517         if (!BN_mod(&r1,I,rsa->q,ctx)) goto err;
 518         if (!meth->bn_mod_exp(&m1,&r1,rsa->dmq1,rsa->q,ctx,
 519                 rsa->_method_mod_q)) goto err;
 520
 521         if (!BN_mod(&r1,I,rsa->p,ctx)) goto err;
 522         if (!meth->bn_mod_exp(r0,&r1,rsa->dmp1,rsa->p,ctx,
 523                 rsa->_method_mod_p)) goto err;
 524
 525         if (!BN_sub(r0,r0,&m1)) goto err;
 526         /* This will help stop the size of r0 increasing, which does
 527          * affect the multiply if it optimised for a power of 2 size */
 528         if (r0->neg)
 529                 if (!BN_add(r0,r0,rsa->p)) goto err;
 530
 531         if (!BN_mul(&r1,r0,rsa->iqmp,ctx)) goto err;
 532         if (!BN_mod(r0,&r1,rsa->p,ctx)) goto err;
 533         /* If p < q it is occasionally possible for the correction of
 534          * adding 'p' if r0 is negative above to leave the result still
 535          * negative. This can break the private key operations: the following
 536          * second correction should *always* correct this rare occurrence.
 537          * This will *never* happen with OpenSSL generated keys because
 538          * they ensure p > q [steve]
 539          */
 540         if (r0->neg)
 541                 if (!BN_add(r0,r0,rsa->p)) goto err;
 542         if (!BN_mul(&r1,r0,rsa->q,ctx)) goto err;
 543         if (!BN_add(r0,&r1,&m1)) goto err;
 544
 545         if (rsa->e && rsa->n)
 546                 {
 547                 if (!rsa->meth->bn_mod_exp(&vrfy,r0,rsa->e,rsa->n,ctx,NULL)) goto err;
 548                 if (BN_cmp(I, &vrfy) != 0)
 549                         {
 550                         if (!rsa->meth->bn_mod_exp(r0,I,rsa->d,rsa->n,ctx,NULL)) goto err;
 551                         }
 552                 }
 553         ret=1;
 554 err:
 555         BN_clear_free(&m1);
 556         BN_clear_free(&r1);
 557         BN_clear_free(&vrfy);
 558         BN_CTX_free(ctx);
 559         return(ret);
 560         }
 561
 562 static int RSA_eay_init(RSA *rsa)
 563         {
 564         rsa->flags|=RSA_FLAG_CACHE_PUBLIC|RSA_FLAG_CACHE_PRIVATE;
 565         return(1);
 566         }
 567
 568 static int RSA_eay_finish(RSA *rsa)
 569         {
 570         if (rsa->_method_mod_n != NULL)
 571                 BN_MONT_CTX_free(rsa->_method_mod_n);
 572         if (rsa->_method_mod_p != NULL)
 573                 BN_MONT_CTX_free(rsa->_method_mod_p);
 574         if (rsa->_method_mod_q != NULL)
 575                 BN_MONT_CTX_free(rsa->_method_mod_q);
 576         return(1);
 577         }
 578
 579 #endif