/* crypto/rsa/rsa_lib.c */

/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)

 * All rights reserved.

 *

 * This package is an SSL implementation written

 * by Eric Young (eay@cryptsoft.com).

 * The implementation was written so as to conform with Netscapes SSL.

 *

 * This library is free for commercial and non-commercial use as long as

 * the following conditions are aheared to.  The following conditions

 * apply to all code found in this distribution, be it the RC4, RSA,

 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation

 * included with this distribution is covered by the same copyright terms

 * except that the holder is Tim Hudson (tjh@cryptsoft.com).

 *

 * Copyright remains Eric Young's, and as such any Copyright notices in

 * the code are not to be removed.

 * If this package is used in a product, Eric Young should be given attribution

 * as the author of the parts of the library used.

 * This can be in the form of a textual message at program startup or

 * in documentation (online or textual) provided with the package.

 *

 * 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 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 acknowledgement:

 *    "This product includes cryptographic software written by

 *     Eric Young (eay@cryptsoft.com)"

 *    The word 'cryptographic' can be left out if the rouines from the library

 *    being used are not cryptographic related :-).

 * 4. If you include any Windows specific code (or a derivative thereof) from

 *    the apps directory (application code) you must include an acknowledgement:

 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"

 *

 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND

 * ANY EXPRESS 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 AUTHOR OR 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.

 *

 * The licence and distribution terms for any publically available version or

 * derivative of this code cannot be changed.  i.e. this code cannot simply be

 * copied and put under another distribution licence

 * [including the GNU Public Licence.]

 */

#include <stdio.h>

#include <openssl/crypto.h>

#include "cryptlib.h"

#include <openssl/lhash.h>

#include <openssl/bn.h>

#include <openssl/rsa.h>

#include <openssl/rand.h>

#ifndef OPENSSL_NO_ENGINE

# include <openssl/engine.h>

#endif

int RSA_size(const RSA *r)

{

    return (BN_num_bytes(r->n));

}

int RSA_public_encrypt(int flen, const unsigned char *from, unsigned char *to,

                       RSA *rsa, int padding)

{

#ifdef OPENSSL_FIPS

    if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD)

        && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)) {

        RSAerr(RSA_F_RSA_PUBLIC_ENCRYPT, RSA_R_NON_FIPS_RSA_METHOD);

        return -1;

    }

#endif

    return (rsa->meth->rsa_pub_enc(flen, from, to, rsa, padding));

}

int RSA_private_encrypt(int flen, const unsigned char *from,

                        unsigned char *to, RSA *rsa, int padding)

{

#ifdef OPENSSL_FIPS

    if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD)

        && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)) {

        RSAerr(RSA_F_RSA_PRIVATE_ENCRYPT, RSA_R_NON_FIPS_RSA_METHOD);

        return -1;

    }

#endif

    return (rsa->meth->rsa_priv_enc(flen, from, to, rsa, padding));

}

int RSA_private_decrypt(int flen, const unsigned char *from,

                        unsigned char *to, RSA *rsa, int padding)

{

#ifdef OPENSSL_FIPS

    if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD)

        && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)) {

        RSAerr(RSA_F_RSA_PRIVATE_DECRYPT, RSA_R_NON_FIPS_RSA_METHOD);

        return -1;

    }

#endif

    return (rsa->meth->rsa_priv_dec(flen, from, to, rsa, padding));

}

int RSA_public_decrypt(int flen, const unsigned char *from, unsigned char *to,

                       RSA *rsa, int padding)

{

#ifdef OPENSSL_FIPS

    if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD)

        && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)) {

        RSAerr(RSA_F_RSA_PUBLIC_DECRYPT, RSA_R_NON_FIPS_RSA_METHOD);

        return -1;

    }

#endif

    return (rsa->meth->rsa_pub_dec(flen, from, to, rsa, padding));

}

int RSA_flags(const RSA *r)

{

    return ((r == NULL) ? 0 : r->meth->flags);

}

void RSA_blinding_off(RSA *rsa)

{

    if (rsa->blinding != NULL) {

        BN_BLINDING_free(rsa->blinding);

        rsa->blinding = NULL;

    }

    rsa->flags &= ~RSA_FLAG_BLINDING;

    rsa->flags |= RSA_FLAG_NO_BLINDING;

}

int RSA_blinding_on(RSA *rsa, BN_CTX *ctx)

{

    int ret = 0;

    if (rsa->blinding != NULL)

        RSA_blinding_off(rsa);

    rsa->blinding = RSA_setup_blinding(rsa, ctx);

    if (rsa->blinding == NULL)

        goto err;

    rsa->flags |= RSA_FLAG_BLINDING;

    rsa->flags &= ~RSA_FLAG_NO_BLINDING;

    ret = 1;

 err:

    return (ret);

}

static BIGNUM *rsa_get_public_exp(const BIGNUM *d, const BIGNUM *p,

                                  const BIGNUM *q, BN_CTX *ctx)

{

    BIGNUM *ret = NULL, *r0, *r1, *r2;

    if (d == NULL || p == NULL || q == NULL)

        return NULL;

    BN_CTX_start(ctx);

    r0 = BN_CTX_get(ctx);

    r1 = BN_CTX_get(ctx);

    r2 = BN_CTX_get(ctx);

    if (r2 == NULL)

        goto err;

    if (!BN_sub(r1, p, BN_value_one()))

        goto err;

    if (!BN_sub(r2, q, BN_value_one()))

        goto err;

    if (!BN_mul(r0, r1, r2, ctx))

        goto err;

    ret = BN_mod_inverse(NULL, d, r0, ctx);

 err:

    BN_CTX_end(ctx);

    return ret;

}

BN_BLINDING *RSA_setup_blinding(RSA *rsa, BN_CTX *in_ctx)

{

    BIGNUM local_n;

    BIGNUM *e, *n;

    BN_CTX *ctx;

    BN_BLINDING *ret = NULL;

    if (in_ctx == NULL) {

        if ((ctx = BN_CTX_new()) == NULL)

            return 0;

    } else

        ctx = in_ctx;

    BN_CTX_start(ctx);

    e = BN_CTX_get(ctx);

    if (e == NULL) {

        RSAerr(RSA_F_RSA_SETUP_BLINDING, ERR_R_MALLOC_FAILURE);

        goto err;

    }

    if (rsa->e == NULL) {

        e = rsa_get_public_exp(rsa->d, rsa->p, rsa->q, ctx);

        if (e == NULL) {

            RSAerr(RSA_F_RSA_SETUP_BLINDING, RSA_R_NO_PUBLIC_EXPONENT);

            goto err;

        }

    } else

        e = rsa->e;

    if ((RAND_status() == 0) && rsa->d != NULL && rsa->d->d != NULL) {

        /*

         * if PRNG is not properly seeded, resort to secret exponent as

         * unpredictable seed

         */

        RAND_add(rsa->d->d, rsa->d->dmax * sizeof rsa->d->d[0], 0.0);

    }

    if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {

        /* Set BN_FLG_CONSTTIME flag */

        n = &local_n;

        BN_with_flags(n, rsa->n, BN_FLG_CONSTTIME);

    } else

        n = rsa->n;

    ret = BN_BLINDING_create_param(NULL, e, n, ctx,

                                   rsa->meth->bn_mod_exp, rsa->_method_mod_n);

    if (ret == NULL) {

        RSAerr(RSA_F_RSA_SETUP_BLINDING, ERR_R_BN_LIB);

        goto err;

    }

    CRYPTO_THREADID_current(BN_BLINDING_thread_id(ret));

 err:

    BN_CTX_end(ctx);

    if (in_ctx == NULL)

        BN_CTX_free(ctx);

    if (rsa->e == NULL)

        BN_free(e);

    return ret;

}