lib/libcrypto/rsa/rsa_chk.c

   1 /* $OpenBSD: rsa_chk.c,v 1.13 2017/01/29 17:49:23 beck Exp $ */
   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 #include "bn_lcl.h"
  56
  57 int
  58 RSA_check_key(const RSA *key)
  59 {
  60         BIGNUM *i, *j, *k, *l, *m;
  61         BN_CTX *ctx;
  62         int r;
  63         int ret = 1;
  64
  65         if (!key->p || !key->q || !key->n || !key->e || !key->d) {
  66                 RSAerror(RSA_R_VALUE_MISSING);
  67                 return 0;
  68         }
  69
  70         i = BN_new();
  71         j = BN_new();
  72         k = BN_new();
  73         l = BN_new();
  74         m = BN_new();
  75         ctx = BN_CTX_new();
  76         if (i == NULL || j == NULL || k == NULL || l == NULL || m == NULL ||
  77             ctx == NULL) {
  78                 ret = -1;
  79                 RSAerror(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                 ret = r;
  87                 if (r != 0)
  88                         goto err;
  89                 RSAerror(RSA_R_P_NOT_PRIME);
  90         }
  91
  92         /* q prime? */
  93         r = BN_is_prime_ex(key->q, BN_prime_checks, NULL, NULL);
  94         if (r != 1) {
  95                 ret = r;
  96                 if (r != 0)
  97                         goto err;
  98                 RSAerror(RSA_R_Q_NOT_PRIME);
  99         }
 100
 101         /* n = p*q? */
 102         r = BN_mul(i, key->p, key->q, ctx);
 103         if (!r) {
 104                 ret = -1;
 105                 goto err;
 106         }
 107
 108         if (BN_cmp(i, key->n) != 0) {
 109                 ret = 0;
 110                 RSAerror(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) {
 117                 ret = -1;
 118                 goto err;
 119         }
 120         r = BN_sub(j, key->q, BN_value_one());
 121         if (!r) {
 122                 ret = -1;
 123                 goto err;
 124         }
 125
 126         /* now compute k = lcm(i,j) */
 127         r = BN_mul(l, i, j, ctx);
 128         if (!r) {
 129                 ret = -1;
 130                 goto err;
 131         }
 132         r = BN_gcd_ct(m, i, j, ctx);
 133         if (!r) {
 134                 ret = -1;
 135                 goto err;
 136         }
 137         r = BN_div_ct(k, NULL, l, m, ctx); /* remainder is 0 */
 138         if (!r) {
 139                 ret = -1;
 140                 goto err;
 141         }
 142
 143         r = BN_mod_mul(i, key->d, key->e, k, ctx);
 144         if (!r) {
 145                 ret = -1;
 146                 goto err;
 147         }
 148
 149         if (!BN_is_one(i)) {
 150                 ret = 0;
 151                 RSAerror(RSA_R_D_E_NOT_CONGRUENT_TO_1);
 152         }
 153
 154         if (key->dmp1 != NULL && key->dmq1 != NULL && key->iqmp != NULL) {
 155                 /* dmp1 = d mod (p-1)? */
 156                 r = BN_sub(i, key->p, BN_value_one());
 157                 if (!r) {
 158                         ret = -1;
 159                         goto err;
 160                 }
 161
 162                 r = BN_mod_ct(j, key->d, i, ctx);
 163                 if (!r) {
 164                         ret = -1;
 165                         goto err;
 166                 }
 167
 168                 if (BN_cmp(j, key->dmp1) != 0) {
 169                         ret = 0;
 170                         RSAerror(RSA_R_DMP1_NOT_CONGRUENT_TO_D);
 171                 }
 172
 173                 /* dmq1 = d mod (q-1)? */
 174                 r = BN_sub(i, key->q, BN_value_one());
 175                 if (!r) {
 176                         ret = -1;
 177                         goto err;
 178                 }
 179
 180                 r = BN_mod_ct(j, key->d, i, ctx);
 181                 if (!r) {
 182                         ret = -1;
 183                         goto err;
 184                 }
 185
 186                 if (BN_cmp(j, key->dmq1) != 0) {
 187                         ret = 0;
 188                         RSAerror(RSA_R_DMQ1_NOT_CONGRUENT_TO_D);
 189                 }
 190
 191                 /* iqmp = q^-1 mod p? */
 192                 if (!BN_mod_inverse_ct(i, key->q, key->p, ctx)) {
 193                         ret = -1;
 194                         goto err;
 195                 }
 196
 197                 if (BN_cmp(i, key->iqmp) != 0) {
 198                         ret = 0;
 199                         RSAerror(RSA_R_IQMP_NOT_INVERSE_OF_Q);
 200                 }
 201         }
 202
 203 err:
 204         BN_free(i);
 205         BN_free(j);
 206         BN_free(k);
 207         BN_free(l);
 208         BN_free(m);
 209         BN_CTX_free(ctx);
 210
 211         return (ret);
 212 }