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      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 (at) 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 	i = BN_new();
     64 	j = BN_new();
     65 	k = BN_new();
     66 	l = BN_new();
     67 	m = BN_new();
     68 	ctx = BN_CTX_new();
     69 	if (i == NULL || j == NULL || k == NULL || l == NULL ||
     70 		m == NULL || ctx == NULL)
     71 		{
     72 		ret = -1;
     73 		RSAerr(RSA_F_RSA_CHECK_KEY, ERR_R_MALLOC_FAILURE);
     74 		goto err;
     75 		}
     76 
     77 	/* p prime? */
     78 	r = BN_is_prime_ex(key->p, BN_prime_checks, NULL, NULL);
     79 	if (r != 1)
     80 		{
     81 		ret = r;
     82 		if (r != 0)
     83 			goto err;
     84 		RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_P_NOT_PRIME);
     85 		}
     86 
     87 	/* q prime? */
     88 	r = BN_is_prime_ex(key->q, BN_prime_checks, NULL, NULL);
     89 	if (r != 1)
     90 		{
     91 		ret = r;
     92 		if (r != 0)
     93 			goto err;
     94 		RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_Q_NOT_PRIME);
     95 		}
     96 
     97 	/* n = p*q? */
     98 	r = BN_mul(i, key->p, key->q, ctx);
     99 	if (!r) { ret = -1; goto err; }
    100 
    101 	if (BN_cmp(i, key->n) != 0)
    102 		{
    103 		ret = 0;
    104 		RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_N_DOES_NOT_EQUAL_P_Q);
    105 		}
    106 
    107 	/* d*e = 1  mod lcm(p-1,q-1)? */
    108 
    109 	r = BN_sub(i, key->p, BN_value_one());
    110 	if (!r) { ret = -1; goto err; }
    111 	r = BN_sub(j, key->q, BN_value_one());
    112 	if (!r) { ret = -1; goto err; }
    113 
    114 	/* now compute k = lcm(i,j) */
    115 	r = BN_mul(l, i, j, ctx);
    116 	if (!r) { ret = -1; goto err; }
    117 	r = BN_gcd(m, i, j, ctx);
    118 	if (!r) { ret = -1; goto err; }
    119 	r = BN_div(k, NULL, l, m, ctx); /* remainder is 0 */
    120 	if (!r) { ret = -1; goto err; }
    121 
    122 	r = BN_mod_mul(i, key->d, key->e, k, ctx);
    123 	if (!r) { ret = -1; goto err; }
    124 
    125 	if (!BN_is_one(i))
    126 		{
    127 		ret = 0;
    128 		RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_D_E_NOT_CONGRUENT_TO_1);
    129 		}
    130 
    131 	if (key->dmp1 != NULL && key->dmq1 != NULL && key->iqmp != NULL)
    132 		{
    133 		/* dmp1 = d mod (p-1)? */
    134 		r = BN_sub(i, key->p, BN_value_one());
    135 		if (!r) { ret = -1; goto err; }
    136 
    137 		r = BN_mod(j, key->d, i, ctx);
    138 		if (!r) { ret = -1; goto err; }
    139 
    140 		if (BN_cmp(j, key->dmp1) != 0)
    141 			{
    142 			ret = 0;
    143 			RSAerr(RSA_F_RSA_CHECK_KEY,
    144 				RSA_R_DMP1_NOT_CONGRUENT_TO_D);
    145 			}
    146 
    147 		/* dmq1 = d mod (q-1)? */
    148 		r = BN_sub(i, key->q, BN_value_one());
    149 		if (!r) { ret = -1; goto err; }
    150 
    151 		r = BN_mod(j, key->d, i, ctx);
    152 		if (!r) { ret = -1; goto err; }
    153 
    154 		if (BN_cmp(j, key->dmq1) != 0)
    155 			{
    156 			ret = 0;
    157 			RSAerr(RSA_F_RSA_CHECK_KEY,
    158 				RSA_R_DMQ1_NOT_CONGRUENT_TO_D);
    159 			}
    160 
    161 		/* iqmp = q^-1 mod p? */
    162 		if(!BN_mod_inverse(i, key->q, key->p, ctx))
    163 			{
    164 			ret = -1;
    165 			goto err;
    166 			}
    167 
    168 		if (BN_cmp(i, key->iqmp) != 0)
    169 			{
    170 			ret = 0;
    171 			RSAerr(RSA_F_RSA_CHECK_KEY,
    172 				RSA_R_IQMP_NOT_INVERSE_OF_Q);
    173 			}
    174 		}
    175 
    176  err:
    177 	if (i != NULL) BN_free(i);
    178 	if (j != NULL) BN_free(j);
    179 	if (k != NULL) BN_free(k);
    180 	if (l != NULL) BN_free(l);
    181 	if (m != NULL) BN_free(m);
    182 	if (ctx != NULL) BN_CTX_free(ctx);
    183 	return (ret);
    184 	}
    185