/* crypto/rsa/rsa_chk.c  -*- Mode: C; c-file-style: "eay" -*- */

 /* ====================================================================

  * Copyright (c) 1999 The OpenSSL Project.  All rights reserved.

  *

  * Redistribution and use in source and binary forms, with or without

  * modification, are permitted provided that the following conditions

  * are met:

  *

  * 1. Redistributions of source code must retain the above copyright

  *    notice, this list of conditions and the following disclaimer. 

  *

  * 2. Redistributions in binary form must reproduce the above copyright

  *    notice, this list of conditions and the following disclaimer in

  *    the documentation and/or other materials provided with the

  *    distribution.

  *

  * 3. All advertising materials mentioning features or use of this

  *    software must display the following acknowledgment:

  *    "This product includes software developed by the OpenSSL Project

  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"

  *

  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to

  *    endorse or promote products derived from this software without

  *    prior written permission. For written permission, please contact

  *    openssl-core@OpenSSL.org.

  *

  * 5. Products derived from this software may not be called "OpenSSL"

  *    nor may "OpenSSL" appear in their names without prior written

  *    permission of the OpenSSL Project.

  *

  * 6. Redistributions of any form whatsoever must retain the following

  *    acknowledgment:

  *    "This product includes software developed by the OpenSSL Project

  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"

  *

  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY

  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR

  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,

  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED

  * OF THE POSSIBILITY OF SUCH DAMAGE.

  * ====================================================================

  */

 #include <openssl/bn.h>

 #include <openssl/err.h>

 #include <openssl/rsa.h>

 EXPORT_C int RSA_check_key(const RSA *key)

 	{

 	BIGNUM *i, *j, *k, *l, *m;

 	BN_CTX *ctx;

 	int r;

 	int ret=1;

 	i = BN_new();

 	j = BN_new();

 	k = BN_new();

 	l = BN_new();

 	m = BN_new();

 	ctx = BN_CTX_new();

 	if (i == NULL || j == NULL || k == NULL || l == NULL ||

 		m == NULL || ctx == NULL)

 		{

 		ret = -1;

 		RSAerr(RSA_F_RSA_CHECK_KEY, ERR_R_MALLOC_FAILURE);

 		goto err;

 		}

 	/* p prime? */

 	r = BN_is_prime_ex(key->p, BN_prime_checks, NULL, NULL);

 	if (r != 1)

 		{

 		ret = r;

 		if (r != 0)

 			goto err;

 		RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_P_NOT_PRIME);

 		}

 	/* q prime? */

 	r = BN_is_prime_ex(key->q, BN_prime_checks, NULL, NULL);

 	if (r != 1)

 		{

 		ret = r;

 		if (r != 0)

 			goto err;

 		RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_Q_NOT_PRIME);

 		}

 	/* n = p*q? */

 	r = BN_mul(i, key->p, key->q, ctx);

 	if (!r) { ret = -1; goto err; }

 	if (BN_cmp(i, key->n) != 0)

 		{

 		ret = 0;

 		RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_N_DOES_NOT_EQUAL_P_Q);

 		}

 	/* d*e = 1  mod lcm(p-1,q-1)? */

 	r = BN_sub(i, key->p, BN_value_one());

 	if (!r) { ret = -1; goto err; }

 	r = BN_sub(j, key->q, BN_value_one());

 	if (!r) { ret = -1; goto err; }

 	/* now compute k = lcm(i,j) */

 	r = BN_mul(l, i, j, ctx);

 	if (!r) { ret = -1; goto err; }

 	r = BN_gcd(m, i, j, ctx);

 	if (!r) { ret = -1; goto err; }

 	r = BN_div(k, NULL, l, m, ctx); /* remainder is 0 */

 	if (!r) { ret = -1; goto err; }

 	r = BN_mod_mul(i, key->d, key->e, k, ctx);

 	if (!r) { ret = -1; goto err; }

 	if (!BN_is_one(i))

 		{

 		ret = 0;

 		RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_D_E_NOT_CONGRUENT_TO_1);

 		}

 	if (key->dmp1 != NULL && key->dmq1 != NULL && key->iqmp != NULL)

 		{

 		/* dmp1 = d mod (p-1)? */

 		r = BN_sub(i, key->p, BN_value_one());

 		if (!r) { ret = -1; goto err; }

 		r = BN_mod(j, key->d, i, ctx);

 		if (!r) { ret = -1; goto err; }

 		if (BN_cmp(j, key->dmp1) != 0)

 			{

 			ret = 0;

 			RSAerr(RSA_F_RSA_CHECK_KEY,

 				RSA_R_DMP1_NOT_CONGRUENT_TO_D);

 			}

 		/* dmq1 = d mod (q-1)? */    

 		r = BN_sub(i, key->q, BN_value_one());

 		if (!r) { ret = -1; goto err; }

 		r = BN_mod(j, key->d, i, ctx);

 		if (!r) { ret = -1; goto err; }

 		if (BN_cmp(j, key->dmq1) != 0)

 			{

 			ret = 0;

 			RSAerr(RSA_F_RSA_CHECK_KEY,

 				RSA_R_DMQ1_NOT_CONGRUENT_TO_D);

 			}

 		/* iqmp = q^-1 mod p? */

 		if(!BN_mod_inverse(i, key->q, key->p, ctx))

 			{

 			ret = -1;

 			goto err;

 			}

 		if (BN_cmp(i, key->iqmp) != 0)

 			{

 			ret = 0;

 			RSAerr(RSA_F_RSA_CHECK_KEY,

 				RSA_R_IQMP_NOT_INVERSE_OF_Q);

 			}

 		}

  err:

 	if (i != NULL) BN_free(i);

 	if (j != NULL) BN_free(j);

 	if (k != NULL) BN_free(k);

 	if (l != NULL) BN_free(l);

 	if (m != NULL) BN_free(m);

 	if (ctx != NULL) BN_CTX_free(ctx);

 	return (ret);

 	}