/* crypto/rsa/rsa_sign.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 "cryptlib.h"

#include <openssl/bn.h>

#include <openssl/rsa.h>

#include <openssl/objects.h>

#include <openssl/x509.h>

/* Size of an SSL signature: MD5+SHA1 */

#define SSL_SIG_LENGTH	36

EXPORT_C int RSA_sign(int type, const unsigned char *m, unsigned int m_len,

	     unsigned char *sigret, unsigned int *siglen, RSA *rsa)

	{

	X509_SIG sig;

	ASN1_TYPE parameter;

	int i,j,ret=1;

	unsigned char *p, *tmps = NULL;

	const unsigned char *s = NULL;

	X509_ALGOR algor;

	ASN1_OCTET_STRING digest;

	if((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_sign)

		{

		return rsa->meth->rsa_sign(type, m, m_len,

			sigret, siglen, rsa);

		}

	/* Special case: SSL signature, just check the length */

	if(type == NID_md5_sha1) {

		if(m_len != SSL_SIG_LENGTH) {

			RSAerr(RSA_F_RSA_SIGN,RSA_R_INVALID_MESSAGE_LENGTH);

			return(0);

		}

		i = SSL_SIG_LENGTH;

		s = m;

	} else {

		sig.algor= &algor;

		sig.algor->algorithm=OBJ_nid2obj(type);

		if (sig.algor->algorithm == NULL)

			{

			RSAerr(RSA_F_RSA_SIGN,RSA_R_UNKNOWN_ALGORITHM_TYPE);

			return(0);

			}

		if (sig.algor->algorithm->length == 0)

			{

			RSAerr(RSA_F_RSA_SIGN,RSA_R_THE_ASN1_OBJECT_IDENTIFIER_IS_NOT_KNOWN_FOR_THIS_MD);

			return(0);

			}

		parameter.type=V_ASN1_NULL;

		parameter.value.ptr=NULL;

		sig.algor->parameter= &parameter;

		sig.digest= &digest;

		sig.digest->data=(unsigned char *)m; /* TMP UGLY CAST */

		sig.digest->length=m_len;

		i=i2d_X509_SIG(&sig,NULL);

	}

	j=RSA_size(rsa);

	if (i > (j-RSA_PKCS1_PADDING_SIZE))

		{

		RSAerr(RSA_F_RSA_SIGN,RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY);

		return(0);

		}

	if(type != NID_md5_sha1) {

		tmps=(unsigned char *)OPENSSL_malloc((unsigned int)j+1);

		if (tmps == NULL)

			{

			RSAerr(RSA_F_RSA_SIGN,ERR_R_MALLOC_FAILURE);

			return(0);

			}

		p=tmps;

		i2d_X509_SIG(&sig,&p);

		s=tmps;

	}

	i=RSA_private_encrypt(i,s,sigret,rsa,RSA_PKCS1_PADDING);

	if (i <= 0)

		ret=0;

	else

		*siglen=i;

	if(type != NID_md5_sha1) {

		OPENSSL_cleanse(tmps,(unsigned int)j+1);

		OPENSSL_free(tmps);

	}

	return(ret);

	}

EXPORT_C int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len,

	     unsigned char *sigbuf, unsigned int siglen, RSA *rsa)

	{

	int i,ret=0,sigtype;

	unsigned char *s;

	X509_SIG *sig=NULL;

	if (siglen != (unsigned int)RSA_size(rsa))

		{

		RSAerr(RSA_F_RSA_VERIFY,RSA_R_WRONG_SIGNATURE_LENGTH);

		return(0);

		}

	if((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_verify)

		{

		return rsa->meth->rsa_verify(dtype, m, m_len,

			sigbuf, siglen, rsa);

		}

	s=(unsigned char *)OPENSSL_malloc((unsigned int)siglen);

	if (s == NULL)

		{

		RSAerr(RSA_F_RSA_VERIFY,ERR_R_MALLOC_FAILURE);

		goto err;

		}

	if((dtype == NID_md5_sha1) && (m_len != SSL_SIG_LENGTH) ) {

			RSAerr(RSA_F_RSA_VERIFY,RSA_R_INVALID_MESSAGE_LENGTH);

			goto err;

	}

	i=RSA_public_decrypt((int)siglen,sigbuf,s,rsa,RSA_PKCS1_PADDING);

	if (i <= 0) goto err;

	/* Special case: SSL signature */

	if(dtype == NID_md5_sha1) {

		if((i != SSL_SIG_LENGTH) || memcmp(s, m, SSL_SIG_LENGTH))

				RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE);

		else ret = 1;

	} else {

		const unsigned char *p=s;

		sig=d2i_X509_SIG(NULL,&p,(long)i);

		if (sig == NULL) goto err;

		/* Excess data can be used to create forgeries */

		if(p != s+i)

			{

			RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE);

			goto err;

			}

		/* Parameters to the signature algorithm can also be used to

		   create forgeries */

		if(sig->algor->parameter

		   && ASN1_TYPE_get(sig->algor->parameter) != V_ASN1_NULL)

			{

			RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE);

			goto err;

			}

		sigtype=OBJ_obj2nid(sig->algor->algorithm);

	#ifdef RSA_DEBUG

		/* put a backward compatibility flag in EAY */

		fprintf(stderr,"in(%s) expect(%s)\n",OBJ_nid2ln(sigtype),

			OBJ_nid2ln(dtype));

	#endif

		if (sigtype != dtype)

			{

			if (((dtype == NID_md5) &&

				(sigtype == NID_md5WithRSAEncryption)) ||

				((dtype == NID_md2) &&

				(sigtype == NID_md2WithRSAEncryption)))

				{

				/* ok, we will let it through */

#if !defined(OPENSSL_NO_STDIO) && !defined(OPENSSL_SYS_WIN16)

				fprintf(stderr,"signature has problems, re-make with post SSLeay045\n");

#endif

				}

			else

				{

				RSAerr(RSA_F_RSA_VERIFY,

						RSA_R_ALGORITHM_MISMATCH);

				goto err;

				}

			}

		if (	((unsigned int)sig->digest->length != m_len) ||

			(memcmp(m,sig->digest->data,m_len) != 0))

			{

			RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE);

			}

		else

			ret=1;

	}

err:

	if (sig != NULL) X509_SIG_free(sig);

	if (s != NULL)

		{

		OPENSSL_cleanse(s,(unsigned int)siglen);

		OPENSSL_free(s);

		}

	return(ret);

	}