/* 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);

 	}