/* 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