crypto/rsa/rsa_crpt.c

   1 /* crypto/rsa/rsa_lib.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 <openssl/crypto.h>
  61 #include "internal/cryptlib.h"
  62 #include <openssl/lhash.h>
  63 #include "internal/bn_int.h"
  64 #include <openssl/rsa.h>
  65 #include <openssl/rand.h>
  66
  67 int RSA_bits(const RSA *r)
  68 {
  69     return (BN_num_bits(r->n));
  70 }
  71
  72 int RSA_size(const RSA *r)
  73 {
  74     return (BN_num_bytes(r->n));
  75 }
  76
  77 int RSA_public_encrypt(int flen, const unsigned char *from, unsigned char *to,
  78                        RSA *rsa, int padding)
  79 {
  80     return (rsa->meth->rsa_pub_enc(flen, from, to, rsa, padding));
  81 }
  82
  83 int RSA_private_encrypt(int flen, const unsigned char *from,
  84                         unsigned char *to, RSA *rsa, int padding)
  85 {
  86     return (rsa->meth->rsa_priv_enc(flen, from, to, rsa, padding));
  87 }
  88
  89 int RSA_private_decrypt(int flen, const unsigned char *from,
  90                         unsigned char *to, RSA *rsa, int padding)
  91 {
  92     return (rsa->meth->rsa_priv_dec(flen, from, to, rsa, padding));
  93 }
  94
  95 int RSA_public_decrypt(int flen, const unsigned char *from, unsigned char *to,
  96                        RSA *rsa, int padding)
  97 {
  98     return (rsa->meth->rsa_pub_dec(flen, from, to, rsa, padding));
  99 }
 100
 101 int RSA_flags(const RSA *r)
 102 {
 103     return ((r == NULL) ? 0 : r->meth->flags);
 104 }
 105
 106 void RSA_blinding_off(RSA *rsa)
 107 {
 108     BN_BLINDING_free(rsa->blinding);
 109     rsa->blinding = NULL;
 110     rsa->flags &= ~RSA_FLAG_BLINDING;
 111     rsa->flags |= RSA_FLAG_NO_BLINDING;
 112 }
 113
 114 int RSA_blinding_on(RSA *rsa, BN_CTX *ctx)
 115 {
 116     int ret = 0;
 117
 118     if (rsa->blinding != NULL)
 119         RSA_blinding_off(rsa);
 120
 121     rsa->blinding = RSA_setup_blinding(rsa, ctx);
 122     if (rsa->blinding == NULL)
 123         goto err;
 124
 125     rsa->flags |= RSA_FLAG_BLINDING;
 126     rsa->flags &= ~RSA_FLAG_NO_BLINDING;
 127     ret = 1;
 128  err:
 129     return (ret);
 130 }
 131
 132 static BIGNUM *rsa_get_public_exp(const BIGNUM *d, const BIGNUM *p,
 133                                   const BIGNUM *q, BN_CTX *ctx)
 134 {
 135     BIGNUM *ret = NULL, *r0, *r1, *r2;
 136
 137     if (d == NULL || p == NULL || q == NULL)
 138         return NULL;
 139
 140     BN_CTX_start(ctx);
 141     r0 = BN_CTX_get(ctx);
 142     r1 = BN_CTX_get(ctx);
 143     r2 = BN_CTX_get(ctx);
 144     if (r2 == NULL)
 145         goto err;
 146
 147     if (!BN_sub(r1, p, BN_value_one()))
 148         goto err;
 149     if (!BN_sub(r2, q, BN_value_one()))
 150         goto err;
 151     if (!BN_mul(r0, r1, r2, ctx))
 152         goto err;
 153
 154     ret = BN_mod_inverse(NULL, d, r0, ctx);
 155  err:
 156     BN_CTX_end(ctx);
 157     return ret;
 158 }
 159
 160 BN_BLINDING *RSA_setup_blinding(RSA *rsa, BN_CTX *in_ctx)
 161 {
 162     BIGNUM *local_n = NULL;
 163     BIGNUM *e, *n;
 164     BN_CTX *ctx;
 165     BN_BLINDING *ret = NULL;
 166
 167     if (in_ctx == NULL) {
 168         if ((ctx = BN_CTX_new()) == NULL)
 169             return 0;
 170     } else
 171         ctx = in_ctx;
 172
 173     BN_CTX_start(ctx);
 174     e = BN_CTX_get(ctx);
 175     if (e == NULL) {
 176         RSAerr(RSA_F_RSA_SETUP_BLINDING, ERR_R_MALLOC_FAILURE);
 177         goto err;
 178     }
 179
 180     if (rsa->e == NULL) {
 181         e = rsa_get_public_exp(rsa->d, rsa->p, rsa->q, ctx);
 182         if (e == NULL) {
 183             RSAerr(RSA_F_RSA_SETUP_BLINDING, RSA_R_NO_PUBLIC_EXPONENT);
 184             goto err;
 185         }
 186     } else
 187         e = rsa->e;
 188
 189     if ((RAND_status() == 0) && rsa->d != NULL
 190         && bn_get_words(rsa->d) != NULL) {
 191         /*
 192          * if PRNG is not properly seeded, resort to secret exponent as
 193          * unpredictable seed
 194          */
 195         RAND_add(bn_get_words(rsa->d), bn_get_dmax(rsa->d) * sizeof(BN_ULONG),
 196                  0.0);
 197     }
 198
 199     if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
 200         /* Set BN_FLG_CONSTTIME flag */
 201         local_n = n = BN_new();
 202         if (local_n == NULL) {
 203             RSAerr(RSA_F_RSA_SETUP_BLINDING, ERR_R_MALLOC_FAILURE);
 204             goto err;
 205         }
 206         BN_with_flags(n, rsa->n, BN_FLG_CONSTTIME);
 207     } else
 208         n = rsa->n;
 209
 210     ret = BN_BLINDING_create_param(NULL, e, n, ctx,
 211                                    rsa->meth->bn_mod_exp, rsa->_method_mod_n);
 212     if (ret == NULL) {
 213         RSAerr(RSA_F_RSA_SETUP_BLINDING, ERR_R_BN_LIB);
 214         goto err;
 215     }
 216     CRYPTO_THREADID_current(BN_BLINDING_thread_id(ret));
 217  err:
 218     BN_CTX_end(ctx);
 219     if (ctx != in_ctx)
 220         BN_CTX_free(ctx);
 221     if (e != rsa->e)
 222         BN_free(e);
 223     BN_free(local_n);
 224
 225     return ret;
 226 }