sl@0: /* rsa_x931.c */
sl@0: /* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL
sl@0:  * project 2005.
sl@0:  */
sl@0: /* ====================================================================
sl@0:  * Copyright (c) 2005 The OpenSSL Project.  All rights reserved.
sl@0:  *
sl@0:  * Redistribution and use in source and binary forms, with or without
sl@0:  * modification, are permitted provided that the following conditions
sl@0:  * are met:
sl@0:  *
sl@0:  * 1. Redistributions of source code must retain the above copyright
sl@0:  *    notice, this list of conditions and the following disclaimer. 
sl@0:  *
sl@0:  * 2. Redistributions in binary form must reproduce the above copyright
sl@0:  *    notice, this list of conditions and the following disclaimer in
sl@0:  *    the documentation and/or other materials provided with the
sl@0:  *    distribution.
sl@0:  *
sl@0:  * 3. All advertising materials mentioning features or use of this
sl@0:  *    software must display the following acknowledgment:
sl@0:  *    "This product includes software developed by the OpenSSL Project
sl@0:  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
sl@0:  *
sl@0:  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
sl@0:  *    endorse or promote products derived from this software without
sl@0:  *    prior written permission. For written permission, please contact
sl@0:  *    licensing@OpenSSL.org.
sl@0:  *
sl@0:  * 5. Products derived from this software may not be called "OpenSSL"
sl@0:  *    nor may "OpenSSL" appear in their names without prior written
sl@0:  *    permission of the OpenSSL Project.
sl@0:  *
sl@0:  * 6. Redistributions of any form whatsoever must retain the following
sl@0:  *    acknowledgment:
sl@0:  *    "This product includes software developed by the OpenSSL Project
sl@0:  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
sl@0:  *
sl@0:  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
sl@0:  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
sl@0:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
sl@0:  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
sl@0:  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
sl@0:  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
sl@0:  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
sl@0:  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
sl@0:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
sl@0:  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
sl@0:  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
sl@0:  * OF THE POSSIBILITY OF SUCH DAMAGE.
sl@0:  * ====================================================================
sl@0:  *
sl@0:  * This product includes cryptographic software written by Eric Young
sl@0:  * (eay@cryptsoft.com).  This product includes software written by Tim
sl@0:  * Hudson (tjh@cryptsoft.com).
sl@0:  *
sl@0:  */
sl@0: 
sl@0: #include <stdio.h>
sl@0: #include "cryptlib.h"
sl@0: #include <openssl/bn.h>
sl@0: #include <openssl/rsa.h>
sl@0: #include <openssl/rand.h>
sl@0: #include <openssl/objects.h>
sl@0: 
sl@0: EXPORT_C int RSA_padding_add_X931(unsigned char *to, int tlen,
sl@0: 	     const unsigned char *from, int flen)
sl@0: 	{
sl@0: 	int j;
sl@0: 	unsigned char *p;
sl@0: 
sl@0: 	/* Absolute minimum amount of padding is 1 header nibble, 1 padding
sl@0: 	 * nibble and 2 trailer bytes: but 1 hash if is already in 'from'.
sl@0: 	 */
sl@0: 
sl@0: 	j = tlen - flen - 2;
sl@0: 
sl@0: 	if (j < 0)
sl@0: 		{
sl@0: 		RSAerr(RSA_F_RSA_PADDING_ADD_X931,RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
sl@0: 		return -1;
sl@0: 		}
sl@0: 	
sl@0: 	p=(unsigned char *)to;
sl@0: 
sl@0: 	/* If no padding start and end nibbles are in one byte */
sl@0: 	if (j == 0)
sl@0: 		*p++ = 0x6A;
sl@0: 	else
sl@0: 		{
sl@0: 		*p++ = 0x6B;
sl@0: 		if (j > 1)
sl@0: 			{
sl@0: 			memset(p, 0xBB, j - 1);
sl@0: 			p += j - 1;
sl@0: 			}
sl@0: 		*p++ = 0xBA;
sl@0: 		}
sl@0: 	memcpy(p,from,(unsigned int)flen);
sl@0: 	p += flen;
sl@0: 	*p = 0xCC;
sl@0: 	return(1);
sl@0: 	}
sl@0: 
sl@0: EXPORT_C int RSA_padding_check_X931(unsigned char *to, int tlen,
sl@0: 	     const unsigned char *from, int flen, int num)
sl@0: 	{
sl@0: 	int i = 0,j;
sl@0: 	const unsigned char *p;
sl@0: 
sl@0: 	p=from;
sl@0: 	if ((num != flen) || ((*p != 0x6A) && (*p != 0x6B)))
sl@0: 		{
sl@0: 		RSAerr(RSA_F_RSA_PADDING_CHECK_X931,RSA_R_INVALID_HEADER);
sl@0: 		return -1;
sl@0: 		}
sl@0: 
sl@0: 	if (*p++ == 0x6B)
sl@0: 		{
sl@0: 		j=flen-3;
sl@0: 		for (i = 0; i < j; i++)
sl@0: 			{
sl@0: 			unsigned char c = *p++;
sl@0: 			if (c == 0xBA)
sl@0: 				break;
sl@0: 			if (c != 0xBB)
sl@0: 				{
sl@0: 				RSAerr(RSA_F_RSA_PADDING_CHECK_X931,
sl@0: 					RSA_R_INVALID_PADDING);
sl@0: 				return -1;
sl@0: 				}
sl@0: 			}
sl@0: 
sl@0: 		j -= i;
sl@0: 
sl@0: 		if (i == 0)
sl@0: 			{
sl@0: 			RSAerr(RSA_F_RSA_PADDING_CHECK_X931, RSA_R_INVALID_PADDING);
sl@0: 			return -1;
sl@0: 			}
sl@0: 
sl@0: 		}
sl@0: 	else j = flen - 2;
sl@0: 
sl@0: 	if (p[j] != 0xCC)
sl@0: 		{
sl@0: 		RSAerr(RSA_F_RSA_PADDING_CHECK_X931, RSA_R_INVALID_TRAILER);
sl@0: 		return -1;
sl@0: 		}
sl@0: 
sl@0: 	memcpy(to,p,(unsigned int)j);
sl@0: 
sl@0: 	return(j);
sl@0: 	}
sl@0: 
sl@0: /* Translate between X931 hash ids and NIDs */
sl@0: 
sl@0: EXPORT_C int RSA_X931_hash_id(int nid)
sl@0: 	{
sl@0: 	switch (nid)
sl@0: 		{
sl@0: 		case NID_sha1:
sl@0: 		return 0x33;
sl@0: 
sl@0: 		case NID_sha256:
sl@0: 		return 0x34;
sl@0: 
sl@0: 		case NID_sha384:
sl@0: 		return 0x36;
sl@0: 
sl@0: 		case NID_sha512:
sl@0: 		return 0x35;
sl@0: 
sl@0: 		}
sl@0: 	return -1;
sl@0: 	}
sl@0: