1 /* crypto/rsa/rsa_chk.c  -*- Mode: C; c-file-style: "eay" -*- */
   2 /* ====================================================================
   3  * Copyright (c) 1999 The OpenSSL Project.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  *
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in
  14  *    the documentation and/or other materials provided with the
  15  *    distribution.
  16  *
  17  * 3. All advertising materials mentioning features or use of this
  18  *    software must display the following acknowledgment:
  19  *    "This product includes software developed by the OpenSSL Project
  20  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  21  *
  22  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  23  *    endorse or promote products derived from this software without
  24  *    prior written permission. For written permission, please contact
  25  *    openssl-core@OpenSSL.org.
  26  *
  27  * 5. Products derived from this software may not be called "OpenSSL"
  28  *    nor may "OpenSSL" appear in their names without prior written
  29  *    permission of the OpenSSL Project.
  30  *
  31  * 6. Redistributions of any form whatsoever must retain the following
  32  *    acknowledgment:
  33  *    "This product includes software developed by the OpenSSL Project
  34  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  35  *
  36  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  37  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  39  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  40  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  41  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  42  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  43  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  44  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  45  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  46  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  47  * OF THE POSSIBILITY OF SUCH DAMAGE.
  48  * ====================================================================
  49  */
  50 
  51 #include <openssl/bn.h>
  52 #include <openssl/err.h>
  53 #include <openssl/rsa.h>
  54 
  55 
  56 int RSA_check_key(const RSA *key)
  57         {
  58         BIGNUM *i, *j, *k, *l, *m;
  59         BN_CTX *ctx;
  60         int r;
  61         int ret=1;
  62 
  63         if (!key->p || !key->q || !key->n || !key->e || !key->d)
  64                 {
  65                 RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_VALUE_MISSING);
  66                 return 0;
  67                 }
  68 
  69         i = BN_new();
  70         j = BN_new();
  71         k = BN_new();
  72         l = BN_new();
  73         m = BN_new();
  74         ctx = BN_CTX_new();
  75         if (i == NULL || j == NULL || k == NULL || l == NULL ||
  76                 m == NULL || ctx == NULL)
  77                 {
  78                 ret = -1;
  79                 RSAerr(RSA_F_RSA_CHECK_KEY, ERR_R_MALLOC_FAILURE);
  80                 goto err;
  81                 }
  82 
  83         /* p prime? */
  84         r = BN_is_prime_ex(key->p, BN_prime_checks, NULL, NULL);
  85         if (r != 1)
  86                 {
  87                 ret = r;
  88                 if (r != 0)
  89                         goto err;
  90                 RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_P_NOT_PRIME);
  91                 }
  92 
  93         /* q prime? */
  94         r = BN_is_prime_ex(key->q, BN_prime_checks, NULL, NULL);
  95         if (r != 1)
  96                 {
  97                 ret = r;
  98                 if (r != 0)
  99                         goto err;
 100                 RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_Q_NOT_PRIME);
 101                 }
 102 
 103         /* n = p*q? */
 104         r = BN_mul(i, key->p, key->q, ctx);
 105         if (!r) { ret = -1; goto err; }
 106 
 107         if (BN_cmp(i, key->n) != 0)
 108                 {
 109                 ret = 0;
 110                 RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_N_DOES_NOT_EQUAL_P_Q);
 111                 }
 112 
 113         /* d*e = 1  mod lcm(p-1,q-1)? */
 114 
 115         r = BN_sub(i, key->p, BN_value_one());
 116         if (!r) { ret = -1; goto err; }
 117         r = BN_sub(j, key->q, BN_value_one());
 118         if (!r) { ret = -1; goto err; }
 119 
 120         /* now compute k = lcm(i,j) */
 121         r = BN_mul(l, i, j, ctx);
 122         if (!r) { ret = -1; goto err; }
 123         r = BN_gcd(m, i, j, ctx);
 124         if (!r) { ret = -1; goto err; }
 125         r = BN_div(k, NULL, l, m, ctx); /* remainder is 0 */
 126         if (!r) { ret = -1; goto err; }
 127 
 128         r = BN_mod_mul(i, key->d, key->e, k, ctx);
 129         if (!r) { ret = -1; goto err; }
 130 
 131         if (!BN_is_one(i))
 132                 {
 133                 ret = 0;
 134                 RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_D_E_NOT_CONGRUENT_TO_1);
 135                 }
 136 
 137         if (key->dmp1 != NULL && key->dmq1 != NULL && key->iqmp != NULL)
 138                 {
 139                 /* dmp1 = d mod (p-1)? */
 140                 r = BN_sub(i, key->p, BN_value_one());
 141                 if (!r) { ret = -1; goto err; }
 142 
 143                 r = BN_mod(j, key->d, i, ctx);
 144                 if (!r) { ret = -1; goto err; }
 145 
 146                 if (BN_cmp(j, key->dmp1) != 0)
 147                         {
 148                         ret = 0;
 149                         RSAerr(RSA_F_RSA_CHECK_KEY,
 150                                 RSA_R_DMP1_NOT_CONGRUENT_TO_D);
 151                         }
 152 
 153                 /* dmq1 = d mod (q-1)? */
 154                 r = BN_sub(i, key->q, BN_value_one());
 155                 if (!r) { ret = -1; goto err; }
 156 
 157                 r = BN_mod(j, key->d, i, ctx);
 158                 if (!r) { ret = -1; goto err; }
 159 
 160                 if (BN_cmp(j, key->dmq1) != 0)
 161                         {
 162                         ret = 0;
 163                         RSAerr(RSA_F_RSA_CHECK_KEY,
 164                                 RSA_R_DMQ1_NOT_CONGRUENT_TO_D);
 165                         }
 166 
 167                 /* iqmp = q^-1 mod p? */
 168                 if(!BN_mod_inverse(i, key->q, key->p, ctx))
 169                         {
 170                         ret = -1;
 171                         goto err;
 172                         }
 173 
 174                 if (BN_cmp(i, key->iqmp) != 0)
 175                         {
 176                         ret = 0;
 177                         RSAerr(RSA_F_RSA_CHECK_KEY,
 178                                 RSA_R_IQMP_NOT_INVERSE_OF_Q);
 179                         }
 180                 }
 181 
 182  err:
 183         if (i != NULL) BN_free(i);
 184         if (j != NULL) BN_free(j);
 185         if (k != NULL) BN_free(k);
 186         if (l != NULL) BN_free(l);
 187         if (m != NULL) BN_free(m);
 188         if (ctx != NULL) BN_CTX_free(ctx);
 189         return (ret);
 190         }