/* 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);

	}