crypto/rsa/rsa_enc.c - third_party/openssl - Git at Google

 /* crypto/rsa/rsa_enc.c */
 /* Copyright (C) 1995-1997 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 "cryptlib.h"
 #include "bn.h"
 #include "rsa.h"
 #include "rand.h"

 #ifndef NOPROTO
 static int RSA_eay_public_encrypt(int flen, unsigned char *from,
 		unsigned char *to, RSA *rsa,int padding);
 static int RSA_eay_private_encrypt(int flen, unsigned char *from,
 		unsigned char *to, RSA *rsa,int padding);
 static int RSA_eay_public_decrypt(int flen, unsigned char *from,
 		unsigned char *to, RSA *rsa,int padding);
 static int RSA_eay_private_decrypt(int flen, unsigned char *from,
 		unsigned char *to, RSA *rsa,int padding);
 static int RSA_eay_mod_exp(BIGNUM *r0, BIGNUM *i, RSA *rsa);
 #else
 static int RSA_eay_public_encrypt();
 static int RSA_eay_private_encrypt();
 static int RSA_eay_public_decrypt();
 static int RSA_eay_private_decrypt();
 static int RSA_eay_mod_exp();
 #endif

 static RSA_METHOD rsa_pkcs1_eay_meth={
 	"Eric Young's PKCS#1 RSA",
 	RSA_eay_public_encrypt,
 	RSA_eay_public_decrypt,
 	RSA_eay_private_encrypt,
 	RSA_eay_private_decrypt,
 	RSA_eay_mod_exp,
 	BN_mod_exp,
 	NULL,
 	NULL,
 	};

 RSA_METHOD *RSA_PKCS1_SSLeay()
 	{
 	return(&rsa_pkcs1_eay_meth);
 	}

 static int RSA_eay_public_encrypt(flen, from, to, rsa, padding)
 int flen;
 unsigned char *from;
 unsigned char *to;
 RSA *rsa;
 int padding;
 	{
 	BIGNUM *f=NULL,*ret=NULL;
 	int i,j,k,num=0,r= -1;
 	unsigned char *p;
 	unsigned char *buf=NULL;
 	BN_CTX *ctx=NULL;

 	if (	(padding != RSA_PKCS1_PADDING) &&
 		(padding != RSA_SSLV23_PADDING))
 		{
 		RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
 		goto err;
 		}

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

 	num=BN_num_bytes(rsa->n);
 	if (flen > (num-11))
 		{
 		RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
 		goto err;
 		}

 	buf=(unsigned char *)Malloc(num);
 	if (buf == NULL)
 		{
 		RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,ERR_R_MALLOC_FAILURE);
 		goto err;
 		}
 	p=(unsigned char *)buf;

 	*(p++)=0;
 	*(p++)=2; /* Public Key BT (Block Type) */

 	/* pad out with non-zero random data */
 	j=num-3-flen;

 	RAND_bytes(p,j);
 	for (i=0; i<j; i++)
 		{
 		if (*p == '\0')
 			do	{
 				RAND_bytes(p,1);
 				} while (*p == '\0');
 		p++;
 		}

 	if (padding == RSA_SSLV23_PADDING)
 		memset(&(p[-8]),3,8);

 	*(p++)='\0';

 	memcpy(p,from,(unsigned int)flen);

 	f=BN_new();
 	ret=BN_new();
 	if ((f == NULL) || (ret == NULL)) goto err;

 	if (BN_bin2bn(buf,num,f) == NULL) goto err;
 	if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx)) 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_free(ctx);
 	if (f != NULL) BN_free(f);
 	if (ret != NULL) BN_free(ret);
 	if (buf != NULL)
 		{
 		memset(buf,0,num);
 		Free(buf);
 		}
 	return(r);
 	}

 static int RSA_eay_private_encrypt(flen, from, to, rsa, padding)
 int flen;
 unsigned char *from;
 unsigned char *to;
 RSA *rsa;
 int padding;
 	{
 	BIGNUM *f=NULL,*ret=NULL;
 	int i,j,k,num=0,r= -1;
 	unsigned char *p;
 	unsigned char *buf=NULL;
 	BN_CTX *ctx=NULL;

 	if (padding != RSA_PKCS1_PADDING)
 		{
 		RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
 		goto err;
 		}

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

 	num=BN_num_bytes(rsa->n);
 	if (flen > (num-11))
 		{
 		RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
 		goto err;
 		}
 	buf=(unsigned char *)Malloc(num);
 	if (buf == NULL)
 		{
 		RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);
 		goto err;
 		}
 	p=buf;

 	*(p++)=0;
 	*(p++)=1; /* Private Key BT (Block Type) */

 	/* padd out with 0xff data */
 	j=num-3-flen;
 	for (i=0; i<j; i++)
 		*(p++)=0xff;
 	*(p++)='\0';
 	memcpy(p,from,(unsigned int)flen);
 	ret=BN_new();
 	f=BN_new();
 	if ((ret == NULL) || (f == NULL)) goto err;
 	if (BN_bin2bn(buf,num,f) == NULL) goto err;
 	if (	(rsa->p != NULL) &&
 		(rsa->q != NULL) &&
 		(rsa->dmp1 != NULL) &&
 		(rsa->dmq1 != NULL) &&
 		(rsa->iqmp != NULL))
 		{ if (!rsa->meth->rsa_mod_exp(ret,f,rsa)) goto err; }
 	else
 		{ if (!rsa->meth->bn_mod_exp(ret,f,rsa->d,rsa->n,ctx)) goto err; }

 	p=buf;
 	BN_bn2bin(ret,p);

 	/* 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_free(ctx);
 	if (ret != NULL) BN_free(ret);
 	if (f != NULL) BN_free(f);
 	if (buf != NULL)
 		{
 		memset(buf,0,num);
 		Free(buf);
 		}
 	return(r);
 	}

 static int RSA_eay_private_decrypt(flen, from, to, rsa,padding)
 int flen;
 unsigned char *from;
 unsigned char *to;
 RSA *rsa;
 int padding;
 	{
 	BIGNUM *f=NULL,*ret=NULL;
 	int i,j,num=0,r= -1;
 	unsigned char *p;
 	unsigned char *buf=NULL;
 	BN_CTX *ctx=NULL;

 	if ((padding != RSA_PKCS1_PADDING) && (padding != RSA_SSLV23_PADDING))
 		{
 		RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
 		goto err;
 		}

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

 	num=BN_num_bytes(rsa->n);

 	buf=(unsigned char *)Malloc(num);
 	if (buf == NULL)
 		{
 		RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
 		goto err;
 		}

 	/* This check was for equallity 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 */
 	ret=BN_new();
 	f=BN_new();
 	if ((ret == NULL) || (f == NULL)) goto err;
 	if (BN_bin2bn(from,(int)flen,f) == NULL) goto err;
 	/* do the decrypt */
 	if (	(rsa->p != NULL) &&
 		(rsa->q != NULL) &&
 		(rsa->dmp1 != NULL) &&
 		(rsa->dmq1 != NULL) &&
 		(rsa->iqmp != NULL))
 		{ if (!rsa->meth->rsa_mod_exp(ret,f,rsa)) goto err; }
 	else
 		{ if (!rsa->meth->bn_mod_exp(ret,f,rsa->d,rsa->n,ctx)) goto err; }

 	p=buf;
 	BN_bn2bin(ret,p);

 	/* BT must be 02 */
 	if (*(p++) != 02)
 		{
 		RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_BLOCK_TYPE_IS_NOT_02);
 		goto err;
 		}

 	/* scan over padding data */
 	j=num-2; /* one for type and one for the prepended 0. */
 	for (i=0; i<j; i++)
 		if (*(p++) == 0) break;

 	if (i == j)
 		{
 		RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_NULL_BEFORE_BLOCK_MISSING);
 		goto err;
 		}

 	if (i < 8)
 		{
 		RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_BAD_PAD_BYTE_COUNT);
 		goto err;
 		}

 #undef RSA_DEBUG
 #ifdef RSA_DEBUG
 	{
 	int z;
 	unsigned char *q;
 	q= &(p[-9]);
 	fprintf(stderr,"\n");
 	for (z=0; z<8; z++) fprintf(stderr,"%02X",q[z]);
 	fprintf(stderr,"\n");
 	}
 #endif

 	if (padding == RSA_SSLV23_PADDING)
 		{
 		int z;
 		unsigned char *q;

 		/* -9 because we have jumped the '\0' */
 		q= &(p[-9]);
 		for (z=0; z<8; z++)
 			{
 			if (*(q++) != 0x03)
 				break;
 			}
 		if (z == 8)
 			{
 			RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_SSLV3_ROLLBACK_ATTACK);
 			goto err;
 			}
 		}

 	/* skip over the '\0' */
 	i++;
 	j-=i;

 	/* output data */
 	memcpy(to,p,(unsigned int)j);
 	r=j;
 err:
 	if (ctx != NULL) BN_CTX_free(ctx);
 	if (f != NULL) BN_free(f);
 	if (ret != NULL) BN_free(ret);
 	if (buf != NULL)
 		{
 		memset(buf,0,num);
 		Free(buf);
 		}
 	return(r);
 	}

 static int RSA_eay_public_decrypt(flen, from, to, rsa, padding)
 int flen;
 unsigned char *from;
 unsigned char *to;
 RSA *rsa;
 int padding;
 	{
 	BIGNUM *f=NULL,*ret=NULL;
 	int i,j,num=0,r= -1;
 	unsigned char *p;
 	unsigned char *buf=NULL;
 	BN_CTX *ctx=NULL;

 	if (padding != RSA_PKCS1_PADDING)
 		{
 		RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
 		goto err;
 		}

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

 	num=BN_num_bytes(rsa->n);
 	buf=(unsigned char *)Malloc(num);
 	if (buf == NULL)
 		{
 		RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE);
 		goto err;
 		}

 	/* This check was for equallity 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;
 		}

 	/* make data into a big number */
 	f=BN_new();
 	ret=BN_new();
 	if ((f == NULL) || (ret == NULL)) goto err;

 	if (BN_bin2bn(from,flen,f) == NULL) goto err;
 	/* do the decrypt */
 	if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx)) goto err;

 	p=buf;
 	i=BN_bn2bin(ret,p);

 	/* BT must be 01 */
 	if (*(p++) != 01)
 		{
 		RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_BLOCK_TYPE_IS_NOT_01);
 		goto err;
 		}

 	/* scan over padding data */
 	j=num-2; /* one for type and one for the prepended 0. */
 	for (i=0; i<j; i++)
 		{
 		if (*p != 0xff) /* should decrypt to 0xff */
 			{
 			if (*p == 0)
 				{ p++; break; }
 			else	{
 				RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_BAD_FIXED_HEADER_DECRYPT);
 				goto err;
 				}
 			}
 		p++;
 		}
 	if (i == j)
 		{
 		RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_NULL_BEFORE_BLOCK_MISSING);
 		goto err;
 		}
 	if (i < 8)
 		{
 		RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_BAD_PAD_BYTE_COUNT);
 		goto err;
 		}

 	/* skip over the '\0' */
 	i++;
 	j-=i;

 	/* output data */
 	memcpy(to,p,(unsigned int)j);
 	r=j;
 err:
 	if (ctx != NULL) BN_CTX_free(ctx);
 	if (f != NULL) BN_free(f);
 	if (ret != NULL) BN_free(ret);
 	if (buf != NULL)
 		{
 		memset(buf,0,num);
 		Free(buf);
 		}
 	return(r);
 	}

 static int RSA_eay_mod_exp(r0, I, rsa)
 BIGNUM *r0;
 BIGNUM *I;
 RSA *rsa;
 	{
 	BIGNUM *r1=NULL,*m1=NULL;
 	int ret=0;
 	BN_CTX *ctx;

 	if ((ctx=BN_CTX_new()) == NULL) goto err;
 	m1=BN_new();
 	r1=BN_new();
 	if ((m1 == NULL) || (r1 == NULL)) goto err;

 	if (!BN_mod(r1,I,rsa->q,ctx)) goto err;
 	if (!rsa->meth->bn_mod_exp(m1,r1,rsa->dmq1,rsa->q,ctx)) goto err;

 	if (!BN_mod(r1,I,rsa->p,ctx)) goto err;
 	if (!rsa->meth->bn_mod_exp(r0,r1,rsa->dmp1,rsa->p,ctx)) goto err;

 	if (!BN_add(r1,r0,rsa->p)) goto err;
 	if (!BN_sub(r0,r1,m1)) goto err;

 	if (!BN_mul(r1,r0,rsa->iqmp)) goto err;
 	if (!BN_mod(r0,r1,rsa->p,ctx)) goto err;
 	if (!BN_mul(r1,r0,rsa->q)) goto err;
 	if (!BN_add(r0,r1,m1)) goto err;

 	ret=1;
 err:
 	if (m1 != NULL) BN_free(m1);
 	if (r1 != NULL) BN_free(r1);
 	BN_CTX_free(ctx);
 	return(ret);
 	}
	/* crypto/rsa/rsa_enc.c */
	/* Copyright (C) 1995-1997 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 "cryptlib.h"
	#include "bn.h"
	#include "rsa.h"
	#include "rand.h"

	#ifndef NOPROTO
	static int RSA_eay_public_encrypt(int flen, unsigned char *from,
	unsigned char to, RSA rsa,int padding);
	static int RSA_eay_private_encrypt(int flen, unsigned char *from,
	unsigned char to, RSA rsa,int padding);
	static int RSA_eay_public_decrypt(int flen, unsigned char *from,
	unsigned char to, RSA rsa,int padding);
	static int RSA_eay_private_decrypt(int flen, unsigned char *from,
	unsigned char to, RSA rsa,int padding);
	static int RSA_eay_mod_exp(BIGNUM r0, BIGNUM i, RSA *rsa);
	#else
	static int RSA_eay_public_encrypt();
	static int RSA_eay_private_encrypt();
	static int RSA_eay_public_decrypt();
	static int RSA_eay_private_decrypt();
	static int RSA_eay_mod_exp();
	#endif

	static RSA_METHOD rsa_pkcs1_eay_meth={
	"Eric Young's PKCS#1 RSA",
	RSA_eay_public_encrypt,
	RSA_eay_public_decrypt,
	RSA_eay_private_encrypt,
	RSA_eay_private_decrypt,
	RSA_eay_mod_exp,
	BN_mod_exp,
	NULL,
	NULL,
	};

	RSA_METHOD *RSA_PKCS1_SSLeay()
	{
	return(&rsa_pkcs1_eay_meth);
	}

	static int RSA_eay_public_encrypt(flen, from, to, rsa, padding)
	int flen;
	unsigned char *from;
	unsigned char *to;
	RSA *rsa;
	int padding;
	{
	BIGNUM f=NULL,ret=NULL;
	int i,j,k,num=0,r= -1;
	unsigned char *p;
	unsigned char *buf=NULL;
	BN_CTX *ctx=NULL;

	if ( (padding != RSA_PKCS1_PADDING) &&
	(padding != RSA_SSLV23_PADDING))
	{
	RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
	goto err;
	}

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

	num=BN_num_bytes(rsa->n);
	if (flen > (num-11))
	{
	RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
	goto err;
	}

	buf=(unsigned char *)Malloc(num);
	if (buf == NULL)
	{
	RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,ERR_R_MALLOC_FAILURE);
	goto err;
	}
	p=(unsigned char *)buf;

	*(p++)=0;
	(p++)=2; / Public Key BT (Block Type) */

	/* pad out with non-zero random data */
	j=num-3-flen;

	RAND_bytes(p,j);
	for (i=0; i<j; i++)
	{
	if (*p == '\0')
	do {
	RAND_bytes(p,1);
	} while (*p == '\0');
	p++;
	}

	if (padding == RSA_SSLV23_PADDING)
	memset(&(p[-8]),3,8);

	*(p++)='\0';

	memcpy(p,from,(unsigned int)flen);

	f=BN_new();
	ret=BN_new();
	if ((f == NULL) \|\| (ret == NULL)) goto err;

	if (BN_bin2bn(buf,num,f) == NULL) goto err;
	if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx)) 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_free(ctx);
	if (f != NULL) BN_free(f);
	if (ret != NULL) BN_free(ret);
	if (buf != NULL)
	{
	memset(buf,0,num);
	Free(buf);
	}
	return(r);
	}

	static int RSA_eay_private_encrypt(flen, from, to, rsa, padding)
	int flen;
	unsigned char *from;
	unsigned char *to;
	RSA *rsa;
	int padding;
	{
	BIGNUM f=NULL,ret=NULL;
	int i,j,k,num=0,r= -1;
	unsigned char *p;
	unsigned char *buf=NULL;
	BN_CTX *ctx=NULL;

	if (padding != RSA_PKCS1_PADDING)
	{
	RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
	goto err;
	}

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

	num=BN_num_bytes(rsa->n);
	if (flen > (num-11))
	{
	RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
	goto err;
	}
	buf=(unsigned char *)Malloc(num);
	if (buf == NULL)
	{
	RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);
	goto err;
	}
	p=buf;

	*(p++)=0;
	(p++)=1; / Private Key BT (Block Type) */

	/* padd out with 0xff data */
	j=num-3-flen;
	for (i=0; i<j; i++)
	*(p++)=0xff;
	*(p++)='\0';
	memcpy(p,from,(unsigned int)flen);
	ret=BN_new();
	f=BN_new();
	if ((ret == NULL) \|\| (f == NULL)) goto err;
	if (BN_bin2bn(buf,num,f) == NULL) goto err;
	if ( (rsa->p != NULL) &&
	(rsa->q != NULL) &&
	(rsa->dmp1 != NULL) &&
	(rsa->dmq1 != NULL) &&
	(rsa->iqmp != NULL))
	{ if (!rsa->meth->rsa_mod_exp(ret,f,rsa)) goto err; }
	else
	{ if (!rsa->meth->bn_mod_exp(ret,f,rsa->d,rsa->n,ctx)) goto err; }

	p=buf;
	BN_bn2bin(ret,p);

	/* 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_free(ctx);
	if (ret != NULL) BN_free(ret);
	if (f != NULL) BN_free(f);
	if (buf != NULL)
	{
	memset(buf,0,num);
	Free(buf);
	}
	return(r);
	}

	static int RSA_eay_private_decrypt(flen, from, to, rsa,padding)
	int flen;
	unsigned char *from;
	unsigned char *to;
	RSA *rsa;
	int padding;
	{
	BIGNUM f=NULL,ret=NULL;
	int i,j,num=0,r= -1;
	unsigned char *p;
	unsigned char *buf=NULL;
	BN_CTX *ctx=NULL;

	if ((padding != RSA_PKCS1_PADDING) && (padding != RSA_SSLV23_PADDING))
	{
	RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
	goto err;
	}

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

	num=BN_num_bytes(rsa->n);

	buf=(unsigned char *)Malloc(num);
	if (buf == NULL)
	{
	RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
	goto err;
	}

	/* This check was for equallity 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 */
	ret=BN_new();
	f=BN_new();
	if ((ret == NULL) \|\| (f == NULL)) goto err;
	if (BN_bin2bn(from,(int)flen,f) == NULL) goto err;
	/* do the decrypt */
	if ( (rsa->p != NULL) &&
	(rsa->q != NULL) &&
	(rsa->dmp1 != NULL) &&
	(rsa->dmq1 != NULL) &&
	(rsa->iqmp != NULL))
	{ if (!rsa->meth->rsa_mod_exp(ret,f,rsa)) goto err; }
	else
	{ if (!rsa->meth->bn_mod_exp(ret,f,rsa->d,rsa->n,ctx)) goto err; }

	p=buf;
	BN_bn2bin(ret,p);

	/* BT must be 02 */
	if (*(p++) != 02)
	{
	RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_BLOCK_TYPE_IS_NOT_02);
	goto err;
	}

	/* scan over padding data */
	j=num-2; /* one for type and one for the prepended 0. */
	for (i=0; i<j; i++)
	if (*(p++) == 0) break;

	if (i == j)
	{
	RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_NULL_BEFORE_BLOCK_MISSING);
	goto err;
	}

	if (i < 8)
	{
	RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_BAD_PAD_BYTE_COUNT);
	goto err;
	}

	#undef RSA_DEBUG
	#ifdef RSA_DEBUG
	{
	int z;
	unsigned char *q;
	q= &(p[-9]);
	fprintf(stderr,"\n");
	for (z=0; z<8; z++) fprintf(stderr,"%02X",q[z]);
	fprintf(stderr,"\n");
	}
	#endif

	if (padding == RSA_SSLV23_PADDING)
	{
	int z;
	unsigned char *q;

	/* -9 because we have jumped the '\0' */
	q= &(p[-9]);
	for (z=0; z<8; z++)
	{
	if (*(q++) != 0x03)
	break;
	}
	if (z == 8)
	{
	RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_SSLV3_ROLLBACK_ATTACK);
	goto err;
	}
	}

	/* skip over the '\0' */
	i++;
	j-=i;

	/* output data */
	memcpy(to,p,(unsigned int)j);
	r=j;
	err:
	if (ctx != NULL) BN_CTX_free(ctx);
	if (f != NULL) BN_free(f);
	if (ret != NULL) BN_free(ret);
	if (buf != NULL)
	{
	memset(buf,0,num);
	Free(buf);
	}
	return(r);
	}

	static int RSA_eay_public_decrypt(flen, from, to, rsa, padding)
	int flen;
	unsigned char *from;
	unsigned char *to;
	RSA *rsa;
	int padding;
	{
	BIGNUM f=NULL,ret=NULL;
	int i,j,num=0,r= -1;
	unsigned char *p;
	unsigned char *buf=NULL;
	BN_CTX *ctx=NULL;

	if (padding != RSA_PKCS1_PADDING)
	{
	RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
	goto err;
	}

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

	num=BN_num_bytes(rsa->n);
	buf=(unsigned char *)Malloc(num);
	if (buf == NULL)
	{
	RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE);
	goto err;
	}

	/* This check was for equallity 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;
	}

	/* make data into a big number */
	f=BN_new();
	ret=BN_new();
	if ((f == NULL) \|\| (ret == NULL)) goto err;

	if (BN_bin2bn(from,flen,f) == NULL) goto err;
	/* do the decrypt */
	if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx)) goto err;

	p=buf;
	i=BN_bn2bin(ret,p);

	/* BT must be 01 */
	if (*(p++) != 01)
	{
	RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_BLOCK_TYPE_IS_NOT_01);
	goto err;
	}

	/* scan over padding data */
	j=num-2; /* one for type and one for the prepended 0. */
	for (i=0; i<j; i++)
	{
	if (p != 0xff) / should decrypt to 0xff */
	{
	if (*p == 0)
	{ p++; break; }
	else {
	RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_BAD_FIXED_HEADER_DECRYPT);
	goto err;
	}
	}
	p++;
	}
	if (i == j)
	{
	RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_NULL_BEFORE_BLOCK_MISSING);
	goto err;
	}
	if (i < 8)
	{
	RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_BAD_PAD_BYTE_COUNT);
	goto err;
	}

	/* skip over the '\0' */
	i++;
	j-=i;

	/* output data */
	memcpy(to,p,(unsigned int)j);
	r=j;
	err:
	if (ctx != NULL) BN_CTX_free(ctx);
	if (f != NULL) BN_free(f);
	if (ret != NULL) BN_free(ret);
	if (buf != NULL)
	{
	memset(buf,0,num);
	Free(buf);
	}
	return(r);
	}

	static int RSA_eay_mod_exp(r0, I, rsa)
	BIGNUM *r0;
	BIGNUM *I;
	RSA *rsa;
	{
	BIGNUM r1=NULL,m1=NULL;
	int ret=0;
	BN_CTX *ctx;

	if ((ctx=BN_CTX_new()) == NULL) goto err;
	m1=BN_new();
	r1=BN_new();
	if ((m1 == NULL) \|\| (r1 == NULL)) goto err;

	if (!BN_mod(r1,I,rsa->q,ctx)) goto err;
	if (!rsa->meth->bn_mod_exp(m1,r1,rsa->dmq1,rsa->q,ctx)) goto err;

	if (!BN_mod(r1,I,rsa->p,ctx)) goto err;
	if (!rsa->meth->bn_mod_exp(r0,r1,rsa->dmp1,rsa->p,ctx)) goto err;

	if (!BN_add(r1,r0,rsa->p)) goto err;
	if (!BN_sub(r0,r1,m1)) goto err;

	if (!BN_mul(r1,r0,rsa->iqmp)) goto err;
	if (!BN_mod(r0,r1,rsa->p,ctx)) goto err;
	if (!BN_mul(r1,r0,rsa->q)) goto err;
	if (!BN_add(r0,r1,m1)) goto err;

	ret=1;
	err:
	if (m1 != NULL) BN_free(m1);
	if (r1 != NULL) BN_free(r1);
	BN_CTX_free(ctx);
	return(ret);
	}