/* crypto/rsa/rsa_eay.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.]

 */

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

 * Copyright (c) 1998-2006 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.

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

 *

 * This product includes cryptographic software written by Eric Young

 * (eay@cryptsoft.com).  This product includes software written by Tim

 * Hudson (tjh@cryptsoft.com).

 *

 */

 /*

 © Portions copyright (c) 2006 Nokia Corporation.  All rights reserved.

 */

#include <stdio.h>

#include "cryptlib.h"

#include <openssl/bn.h>

#include <openssl/rsa.h>

#include <openssl/rand.h>

#if (defined(SYMBIAN) && (defined(__WINSCW__) || defined(__WINS__)))

#include "libcrypto_wsd_macros.h"

#include "libcrypto_wsd.h"

#endif

#ifndef RSA_NULL

static int RSA_eay_public_encrypt(int flen, const unsigned char *from,

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

static int RSA_eay_private_encrypt(int flen, const unsigned char *from,

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

static int RSA_eay_public_decrypt(int flen, const unsigned char *from,

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

static int RSA_eay_private_decrypt(int flen, const unsigned char *from,

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

static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *i, RSA *rsa, BN_CTX *ctx);

static int RSA_eay_init(RSA *rsa);

static int RSA_eay_finish(RSA *rsa);

#ifndef EMULATOR

static RSA_METHOD rsa_pkcs1_eay_meth={

	"Eric Young's PKCS#1 RSA",

	RSA_eay_public_encrypt,

	RSA_eay_public_decrypt, /* signature verification */

	RSA_eay_private_encrypt, /* signing */

	RSA_eay_private_decrypt,

	RSA_eay_mod_exp,

	BN_mod_exp_mont, /* XXX probably we should not use Montgomery if  e == 3 */

	RSA_eay_init,

	RSA_eay_finish,

	0, /* flags */

	NULL,

	0, /* rsa_sign */

	0, /* rsa_verify */

	NULL /* rsa_keygen */

	};

#else

GET_STATIC_VAR_FROM_TLS(rsa_pkcs1_eay_meth,rsa_eay,RSA_METHOD )

#define rsa_pkcs1_eay_meth (*GET_WSD_VAR_NAME(rsa_pkcs1_eay_meth,rsa_eay,s)())

const RSA_METHOD temp_s_rsa_pkcs1_eay_meth={

	"Eric Young's PKCS#1 RSA",

	RSA_eay_public_encrypt,

	RSA_eay_public_decrypt, /* signature verification */

	RSA_eay_private_encrypt, /* signing */

	RSA_eay_private_decrypt,

	RSA_eay_mod_exp,

	BN_mod_exp_mont, /* XXX probably we should not use Montgomery if  e == 3 */

	RSA_eay_init,

	RSA_eay_finish,

	0, /* flags */

	NULL,

	0, /* rsa_sign */

	0, /* rsa_verify */

	NULL /* rsa_keygen */

	};

#endif	

EXPORT_C const RSA_METHOD *RSA_PKCS1_SSLeay(void)

	{

	return(&rsa_pkcs1_eay_meth);

	}

/* Usage example;

 *    MONT_HELPER(rsa, bn_ctx, p, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);

 */

#define MONT_HELPER(rsa, ctx, m, pre_cond, err_instr) \

	if((pre_cond) && ((rsa)->_method_mod_##m == NULL) && \

			!BN_MONT_CTX_set_locked(&((rsa)->_method_mod_##m), \

				CRYPTO_LOCK_RSA, \

				(rsa)->m, (ctx))) \

		err_instr

static int RSA_eay_public_encrypt(int flen, const unsigned char *from,

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

	{

	BIGNUM *f,*ret;

	int i,j,k,num=0,r= -1;

	unsigned char *buf=NULL;

	BN_CTX *ctx=NULL;

	if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS)

		{

		RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_MODULUS_TOO_LARGE);

		return -1;

		}

	if (BN_ucmp(rsa->n, rsa->e) <= 0)

		{

		RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);

		return -1;

		}

	/* for large moduli, enforce exponent limit */

	if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS)

		{

		if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS)

			{

			RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);

			return -1;

			}

		}

	if ((ctx=BN_CTX_new()) == NULL) goto err;

	BN_CTX_start(ctx);

	f = BN_CTX_get(ctx);

	ret = BN_CTX_get(ctx);

	num=BN_num_bytes(rsa->n);

	buf = OPENSSL_malloc(num);

	if (!f || !ret || !buf)

		{

		RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,ERR_R_MALLOC_FAILURE);

		goto err;

		}

	switch (padding)

		{

	case RSA_PKCS1_PADDING:

		i=RSA_padding_add_PKCS1_type_2(buf,num,from,flen);

		break;

#ifndef OPENSSL_NO_SHA

	case RSA_PKCS1_OAEP_PADDING:

	        i=RSA_padding_add_PKCS1_OAEP(buf,num,from,flen,NULL,0);

		break;

#endif

	case RSA_SSLV23_PADDING:

		i=RSA_padding_add_SSLv23(buf,num,from,flen);

		break;

	case RSA_NO_PADDING:

		i=RSA_padding_add_none(buf,num,from,flen);

		break;

	default:

		RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);

		goto err;

		}

	if (i <= 0) goto err;

	if (BN_bin2bn(buf,num,f) == NULL) goto err;

	if (BN_ucmp(f, rsa->n) >= 0)

		{	

		/* usually the padding functions would catch this */

		RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);

		goto err;

		}

	MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);

	if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx,

		rsa->_method_mod_n)) goto err;

	/* put in leading 0 bytes if the number is less than the

	 * length of the modulus */

	j=BN_num_bytes(ret);

	i=BN_bn2bin(ret,&(to[num-j]));

	for (k=0; k<(num-i); k++)

		to[k]=0;

	r=num;

err:

	if (ctx != NULL)

		{

		BN_CTX_end(ctx);

		BN_CTX_free(ctx);

		}

	if (buf != NULL) 

		{

		OPENSSL_cleanse(buf,num);

		OPENSSL_free(buf);

		}

	return(r);

	}

static BN_BLINDING *rsa_get_blinding(RSA *rsa, int *local, BN_CTX *ctx)

{

	BN_BLINDING *ret;

	int got_write_lock = 0;

	CRYPTO_r_lock(CRYPTO_LOCK_RSA);

	if (rsa->blinding == NULL)

		{

		CRYPTO_r_unlock(CRYPTO_LOCK_RSA);

		CRYPTO_w_lock(CRYPTO_LOCK_RSA);

		got_write_lock = 1;

		if (rsa->blinding == NULL)

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

		}

	ret = rsa->blinding;

	if (ret == NULL)

		goto err;

	if (BN_BLINDING_get_thread_id(ret) == CRYPTO_thread_id())

		{

		/* rsa->blinding is ours! */

		*local = 1;

		}

	else

		{

		/* resort to rsa->mt_blinding instead */

		*local = 0; /* instructs rsa_blinding_convert(), rsa_blinding_invert()

		             * that the BN_BLINDING is shared, meaning that accesses

		             * require locks, and that the blinding factor must be

		             * stored outside the BN_BLINDING

		             */

		if (rsa->mt_blinding == NULL)

			{

			if (!got_write_lock)

				{

				CRYPTO_r_unlock(CRYPTO_LOCK_RSA);

				CRYPTO_w_lock(CRYPTO_LOCK_RSA);

				got_write_lock = 1;

				}

			if (rsa->mt_blinding == NULL)

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

			}

		ret = rsa->mt_blinding;

		}

 err:

	if (got_write_lock)

		CRYPTO_w_unlock(CRYPTO_LOCK_RSA);

	else

		CRYPTO_r_unlock(CRYPTO_LOCK_RSA);

	return ret;

}

static int rsa_blinding_convert(BN_BLINDING *b, int local, BIGNUM *f,

	BIGNUM *r, BN_CTX *ctx)

{

	if (local)

		return BN_BLINDING_convert_ex(f, NULL, b, ctx);

	else

		{

		int ret;

		CRYPTO_r_lock(CRYPTO_LOCK_RSA_BLINDING);

		ret = BN_BLINDING_convert_ex(f, r, b, ctx);

		CRYPTO_r_unlock(CRYPTO_LOCK_RSA_BLINDING);

		return ret;

		}

}

static int rsa_blinding_invert(BN_BLINDING *b, int local, BIGNUM *f,

	BIGNUM *r, BN_CTX *ctx)

{

	if (local)

		return BN_BLINDING_invert_ex(f, NULL, b, ctx);

	else

		{

		int ret;

		CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING);

		ret = BN_BLINDING_invert_ex(f, r, b, ctx);

		CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING);

		return ret;

		}

}

/* signing */

static int RSA_eay_private_encrypt(int flen, const unsigned char *from,

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

	{

	BIGNUM *f, *ret, *br, *res;

	int i,j,k,num=0,r= -1;

	unsigned char *buf=NULL;

	BN_CTX *ctx=NULL;

	int local_blinding = 0;

	BN_BLINDING *blinding = NULL;

	if ((ctx=BN_CTX_new()) == NULL) goto err;

	BN_CTX_start(ctx);

	f   = BN_CTX_get(ctx);

	br  = BN_CTX_get(ctx);

	ret = BN_CTX_get(ctx);

	num = BN_num_bytes(rsa->n);

	buf = OPENSSL_malloc(num);

	if(!f || !ret || !buf)

		{

		RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);

		goto err;

		}

	switch (padding)

		{

	case RSA_PKCS1_PADDING:

		i=RSA_padding_add_PKCS1_type_1(buf,num,from,flen);

		break;

	case RSA_X931_PADDING:

		i=RSA_padding_add_X931(buf,num,from,flen);

		break;

	case RSA_NO_PADDING:

		i=RSA_padding_add_none(buf,num,from,flen);

		break;

	case RSA_SSLV23_PADDING:

	default:

		RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);

		goto err;

		}

	if (i <= 0) goto err;

	if (BN_bin2bn(buf,num,f) == NULL) goto err;

	if (BN_ucmp(f, rsa->n) >= 0)

		{	

		/* usually the padding functions would catch this */

		RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);

		goto err;

		}

	if (!(rsa->flags & RSA_FLAG_NO_BLINDING))

		{

				blinding = rsa_get_blinding(rsa, &local_blinding, ctx);

		if (blinding == NULL)

			{

			RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);

			goto err;

			}

		}

	if (blinding != NULL)

		if (!rsa_blinding_convert(blinding, local_blinding, f, br, ctx))

			goto err;

	if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||

		((rsa->p != NULL) &&

		(rsa->q != NULL) &&

		(rsa->dmp1 != NULL) &&

		(rsa->dmq1 != NULL) &&

		(rsa->iqmp != NULL)) )

		{ 

		if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err;

		}

	else

		{

		BIGNUM local_d;

		BIGNUM *d = NULL;

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

			{

			BN_init(&local_d);

			d = &local_d;

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

			}

		else

			d = rsa->d;

		MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);

		if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx,

				rsa->_method_mod_n)) goto err;

		}

	if (blinding)

		if (!rsa_blinding_invert(blinding, local_blinding, ret, br, ctx))

			goto err;

	if (padding == RSA_X931_PADDING)

		{

		BN_sub(f, rsa->n, ret);

		if (BN_cmp(ret, f))

			res = f;

		else

			res = ret;

		}

	else

		res = ret;

	/* put in leading 0 bytes if the number is less than the

	 * length of the modulus */

	j=BN_num_bytes(res);

	i=BN_bn2bin(res,&(to[num-j]));

	for (k=0; k<(num-i); k++)

		to[k]=0;

	r=num;

err:

	if (ctx != NULL)

		{

		BN_CTX_end(ctx);

		BN_CTX_free(ctx);

		}

	if (buf != NULL)

		{

		OPENSSL_cleanse(buf,num);

		OPENSSL_free(buf);

		}

	return(r);

	}

static int RSA_eay_private_decrypt(int flen, const unsigned char *from,

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

	{

	BIGNUM *f, *ret, *br;

	int j,num=0,r= -1;

	unsigned char *p;

	unsigned char *buf=NULL;

	BN_CTX *ctx=NULL;

	int local_blinding = 0;

	BN_BLINDING *blinding = NULL;

	if((ctx = BN_CTX_new()) == NULL) goto err;

	BN_CTX_start(ctx);

	f   = BN_CTX_get(ctx);

	br  = BN_CTX_get(ctx);

	ret = BN_CTX_get(ctx);

	num = BN_num_bytes(rsa->n);

	buf = OPENSSL_malloc(num);

	if(!f || !ret || !buf)

		{

		RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);

		goto err;

		}

	/* This check was for equality but PGP does evil things

	 * and chops off the top '0' bytes */

	if (flen > num)

		{

		RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);

		goto err;

		}

	/* make data into a big number */

	if (BN_bin2bn(from,(int)flen,f) == NULL) goto err;

	if (BN_ucmp(f, rsa->n) >= 0)

		{

		RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);

		goto err;

		}

	if (!(rsa->flags & RSA_FLAG_NO_BLINDING))

		{

			blinding = rsa_get_blinding(rsa, &local_blinding, ctx);

		if (blinding == NULL)

			{

			RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);

			goto err;

			}

		}

	if (blinding != NULL)

		if (!rsa_blinding_convert(blinding, local_blinding, f, br, ctx))

			goto err;

	/* do the decrypt */

	if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||

		((rsa->p != NULL) &&

		(rsa->q != NULL) &&

		(rsa->dmp1 != NULL) &&

		(rsa->dmq1 != NULL) &&

		(rsa->iqmp != NULL)) )

		{

		if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err;

		}

	else

		{

		BIGNUM local_d;

		BIGNUM *d = NULL;

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

			{

			d = &local_d;

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

			}

		else

			d = rsa->d;

		MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);

		if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx,

				rsa->_method_mod_n))

		  goto err;

		}

	if (blinding)

		if (!rsa_blinding_invert(blinding, local_blinding, ret, br, ctx))

			goto err;

	p=buf;

	j=BN_bn2bin(ret,p); /* j is only used with no-padding mode */

	switch (padding)

		{

	case RSA_PKCS1_PADDING:

		r=RSA_padding_check_PKCS1_type_2(to,num,buf,j,num);

		break;

#ifndef OPENSSL_NO_SHA

        case RSA_PKCS1_OAEP_PADDING:

	        r=RSA_padding_check_PKCS1_OAEP(to,num,buf,j,num,NULL,0);

                break;

#endif

 	case RSA_SSLV23_PADDING:

		r=RSA_padding_check_SSLv23(to,num,buf,j,num);

		break;

	case RSA_NO_PADDING:

		r=RSA_padding_check_none(to,num,buf,j,num);

		break;

	default:

		RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);

		goto err;

		}

	if (r < 0)

		RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_PADDING_CHECK_FAILED);

err:

	if (ctx != NULL)

		{

		BN_CTX_end(ctx);

		BN_CTX_free(ctx);

		}

	if (buf != NULL)

		{

		OPENSSL_cleanse(buf,num);

		OPENSSL_free(buf);

		}

	return(r);

	}

/* signature verification */

static int RSA_eay_public_decrypt(int flen, const unsigned char *from,

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

	{

	BIGNUM *f,*ret;

	int i,num=0,r= -1;

	unsigned char *p;

	unsigned char *buf=NULL;

	BN_CTX *ctx=NULL;

	if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS)

		{

		RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE);

		return -1;

		}

	if (BN_ucmp(rsa->n, rsa->e) <= 0)

		{

		RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);

		return -1;

		}

	/* for large moduli, enforce exponent limit */

	if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS)

		{

		if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS)

			{

			RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);

			return -1;

			}

		}

	if((ctx = BN_CTX_new()) == NULL) goto err;

	BN_CTX_start(ctx);

	f = BN_CTX_get(ctx);

	ret = BN_CTX_get(ctx);

	num=BN_num_bytes(rsa->n);

	buf = OPENSSL_malloc(num);

	if(!f || !ret || !buf)

		{

		RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE);

		goto err;

		}

	/* This check was for equality but PGP does evil things

	 * and chops off the top '0' bytes */

	if (flen > num)

		{

		RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);

		goto err;

		}

	if (BN_bin2bn(from,flen,f) == NULL) goto err;

	if (BN_ucmp(f, rsa->n) >= 0)

		{

		RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);

		goto err;

		}

	MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);

	if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx,

		rsa->_method_mod_n)) goto err;

	if ((padding == RSA_X931_PADDING) && ((ret->d[0] & 0xf) != 12))

		BN_sub(ret, rsa->n, ret);

	p=buf;

	i=BN_bn2bin(ret,p);

	switch (padding)

		{

	case RSA_PKCS1_PADDING:

		r=RSA_padding_check_PKCS1_type_1(to,num,buf,i,num);

		break;

	case RSA_X931_PADDING:

		r=RSA_padding_check_X931(to,num,buf,i,num);

		break;

	case RSA_NO_PADDING:

		r=RSA_padding_check_none(to,num,buf,i,num);

		break;

	default:

		RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);

		goto err;

		}

	if (r < 0)

		RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_PADDING_CHECK_FAILED);

err:

	if (ctx != NULL)

		{

		BN_CTX_end(ctx);

		BN_CTX_free(ctx);

		}

	if (buf != NULL)

		{

		OPENSSL_cleanse(buf,num);

		OPENSSL_free(buf);

		}

	return(r);

	}

static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)

	{

	BIGNUM *r1,*m1,*vrfy;

	BIGNUM local_dmp1,local_dmq1,local_c,local_r1;

	BIGNUM *dmp1,*dmq1,*c,*pr1;

	int bn_flags;

	int ret=0;

	BN_CTX_start(ctx);

	r1 = BN_CTX_get(ctx);

	m1 = BN_CTX_get(ctx);

	vrfy = BN_CTX_get(ctx);

	/* Make sure mod_inverse in montgomerey intialization use correct 

	 * BN_FLG_CONSTTIME flag.

	 */

	bn_flags = rsa->p->flags;

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

		{

		rsa->p->flags |= BN_FLG_CONSTTIME;

		}

	MONT_HELPER(rsa, ctx, p, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);

	/* We restore bn_flags back */

	rsa->p->flags = bn_flags;

        /* Make sure mod_inverse in montgomerey intialization use correct

         * BN_FLG_CONSTTIME flag.

         */

	bn_flags = rsa->q->flags;

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

		{

		rsa->q->flags |= BN_FLG_CONSTTIME;

		}

	MONT_HELPER(rsa, ctx, q, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);

	/* We restore bn_flags back */

	rsa->q->flags = bn_flags;	

	MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);

	/* compute I mod q */

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

		{

		c = &local_c;

		BN_with_flags(c, I, BN_FLG_CONSTTIME);

		if (!BN_mod(r1,c,rsa->q,ctx)) goto err;

		}

	else

		{

		if (!BN_mod(r1,I,rsa->q,ctx)) goto err;

		}

	/* compute r1^dmq1 mod q */

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

		{

		dmq1 = &local_dmq1;

		BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME);

		}

	else

		dmq1 = rsa->dmq1;

	if (!rsa->meth->bn_mod_exp(m1,r1,dmq1,rsa->q,ctx,

		rsa->_method_mod_q)) goto err;

	/* compute I mod p */

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

		{

		c = &local_c;

		BN_with_flags(c, I, BN_FLG_CONSTTIME);

		if (!BN_mod(r1,c,rsa->p,ctx)) goto err;

		}

	else

		{

		if (!BN_mod(r1,I,rsa->p,ctx)) goto err;

		}

	/* compute r1^dmp1 mod p */

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

		{

		dmp1 = &local_dmp1;

		BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME);

		}

	else

		dmp1 = rsa->dmp1;

	if (!rsa->meth->bn_mod_exp(r0,r1,dmp1,rsa->p,ctx,

		rsa->_method_mod_p)) goto err;

	if (!BN_sub(r0,r0,m1)) goto err;

	/* This will help stop the size of r0 increasing, which does

	 * affect the multiply if it optimised for a power of 2 size */

	if (BN_is_negative(r0))

		if (!BN_add(r0,r0,rsa->p)) goto err;

	if (!BN_mul(r1,r0,rsa->iqmp,ctx)) goto err;

	/* Turn BN_FLG_CONSTTIME flag on before division operation */

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

		{

		pr1 = &local_r1;

		BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);

		}

	else

		pr1 = r1;

	if (!BN_mod(r0,pr1,rsa->p,ctx)) goto err;

	/* If p < q it is occasionally possible for the correction of

         * adding 'p' if r0 is negative above to leave the result still

	 * negative. This can break the private key operations: the following

	 * second correction should *always* correct this rare occurrence.

	 * This will *never* happen with OpenSSL generated keys because

         * they ensure p > q [steve]

         */

	if (BN_is_negative(r0))

		if (!BN_add(r0,r0,rsa->p)) goto err;

	if (!BN_mul(r1,r0,rsa->q,ctx)) goto err;

	if (!BN_add(r0,r1,m1)) goto err;

	if (rsa->e && rsa->n)

		{

		if (!rsa->meth->bn_mod_exp(vrfy,r0,rsa->e,rsa->n,ctx,rsa->_method_mod_n)) goto err;

		/* If 'I' was greater than (or equal to) rsa->n, the operation

		 * will be equivalent to using 'I mod n'. However, the result of

		 * the verify will *always* be less than 'n' so we don't check

		 * for absolute equality, just congruency. */

		if (!BN_sub(vrfy, vrfy, I)) goto err;

		if (!BN_mod(vrfy, vrfy, rsa->n, ctx)) goto err;

		if (BN_is_negative(vrfy))

			if (!BN_add(vrfy, vrfy, rsa->n)) goto err;

		if (!BN_is_zero(vrfy))

			{

			/* 'I' and 'vrfy' aren't congruent mod n. Don't leak

			 * miscalculated CRT output, just do a raw (slower)

			 * mod_exp and return that instead. */

			BIGNUM local_d;

			BIGNUM *d = NULL;

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

				{

				d = &local_d;

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

				}

			else

				d = rsa->d;

			if (!rsa->meth->bn_mod_exp(r0,I,d,rsa->n,ctx,

						   rsa->_method_mod_n)) goto err;

			}

		}

	ret=1;

err:

	BN_CTX_end(ctx);

	return(ret);

	}

static int RSA_eay_init(RSA *rsa)

	{

	rsa->flags|=RSA_FLAG_CACHE_PUBLIC|RSA_FLAG_CACHE_PRIVATE;

	return(1);

	}

static int RSA_eay_finish(RSA *rsa)

	{

	if (rsa->_method_mod_n != NULL)

		BN_MONT_CTX_free(rsa->_method_mod_n);

	if (rsa->_method_mod_p != NULL)

		BN_MONT_CTX_free(rsa->_method_mod_p);

	if (rsa->_method_mod_q != NULL)

		BN_MONT_CTX_free(rsa->_method_mod_q);

	return(1);

	}

#endif