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