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      1 /* rsa_x931.c */
      2 /* Written by Dr Stephen N Henson (steve (at) openssl.org) for the OpenSSL
      3  * project 2005.
      4  */
      5 /* ====================================================================
      6  * Copyright (c) 2005 The OpenSSL Project.  All rights reserved.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  *
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  *
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in
     17  *    the documentation and/or other materials provided with the
     18  *    distribution.
     19  *
     20  * 3. All advertising materials mentioning features or use of this
     21  *    software must display the following acknowledgment:
     22  *    "This product includes software developed by the OpenSSL Project
     23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
     24  *
     25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
     26  *    endorse or promote products derived from this software without
     27  *    prior written permission. For written permission, please contact
     28  *    licensing (at) OpenSSL.org.
     29  *
     30  * 5. Products derived from this software may not be called "OpenSSL"
     31  *    nor may "OpenSSL" appear in their names without prior written
     32  *    permission of the OpenSSL Project.
     33  *
     34  * 6. Redistributions of any form whatsoever must retain the following
     35  *    acknowledgment:
     36  *    "This product includes software developed by the OpenSSL Project
     37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
     38  *
     39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
     40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
     43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
     50  * OF THE POSSIBILITY OF SUCH DAMAGE.
     51  * ====================================================================
     52  *
     53  * This product includes cryptographic software written by Eric Young
     54  * (eay (at) cryptsoft.com).  This product includes software written by Tim
     55  * Hudson (tjh (at) cryptsoft.com).
     56  *
     57  */
     58 
     59 #include <stdio.h>
     60 #include "cryptlib.h"
     61 #include <openssl/bn.h>
     62 #include <openssl/rsa.h>
     63 #include <openssl/rand.h>
     64 #include <openssl/objects.h>
     65 
     66 int RSA_padding_add_X931(unsigned char *to, int tlen,
     67 	     const unsigned char *from, int flen)
     68 	{
     69 	int j;
     70 	unsigned char *p;
     71 
     72 	/* Absolute minimum amount of padding is 1 header nibble, 1 padding
     73 	 * nibble and 2 trailer bytes: but 1 hash if is already in 'from'.
     74 	 */
     75 
     76 	j = tlen - flen - 2;
     77 
     78 	if (j < 0)
     79 		{
     80 		RSAerr(RSA_F_RSA_PADDING_ADD_X931,RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
     81 		return -1;
     82 		}
     83 
     84 	p=(unsigned char *)to;
     85 
     86 	/* If no padding start and end nibbles are in one byte */
     87 	if (j == 0)
     88 		*p++ = 0x6A;
     89 	else
     90 		{
     91 		*p++ = 0x6B;
     92 		if (j > 1)
     93 			{
     94 			memset(p, 0xBB, j - 1);
     95 			p += j - 1;
     96 			}
     97 		*p++ = 0xBA;
     98 		}
     99 	memcpy(p,from,(unsigned int)flen);
    100 	p += flen;
    101 	*p = 0xCC;
    102 	return(1);
    103 	}
    104 
    105 int RSA_padding_check_X931(unsigned char *to, int tlen,
    106 	     const unsigned char *from, int flen, int num)
    107 	{
    108 	int i = 0,j;
    109 	const unsigned char *p;
    110 
    111 	p=from;
    112 	if ((num != flen) || ((*p != 0x6A) && (*p != 0x6B)))
    113 		{
    114 		RSAerr(RSA_F_RSA_PADDING_CHECK_X931,RSA_R_INVALID_HEADER);
    115 		return -1;
    116 		}
    117 
    118 	if (*p++ == 0x6B)
    119 		{
    120 		j=flen-3;
    121 		for (i = 0; i < j; i++)
    122 			{
    123 			unsigned char c = *p++;
    124 			if (c == 0xBA)
    125 				break;
    126 			if (c != 0xBB)
    127 				{
    128 				RSAerr(RSA_F_RSA_PADDING_CHECK_X931,
    129 					RSA_R_INVALID_PADDING);
    130 				return -1;
    131 				}
    132 			}
    133 
    134 		j -= i;
    135 
    136 		if (i == 0)
    137 			{
    138 			RSAerr(RSA_F_RSA_PADDING_CHECK_X931, RSA_R_INVALID_PADDING);
    139 			return -1;
    140 			}
    141 
    142 		}
    143 	else j = flen - 2;
    144 
    145 	if (p[j] != 0xCC)
    146 		{
    147 		RSAerr(RSA_F_RSA_PADDING_CHECK_X931, RSA_R_INVALID_TRAILER);
    148 		return -1;
    149 		}
    150 
    151 	memcpy(to,p,(unsigned int)j);
    152 
    153 	return(j);
    154 	}
    155 
    156 /* Translate between X931 hash ids and NIDs */
    157 
    158 int RSA_X931_hash_id(int nid)
    159 	{
    160 	switch (nid)
    161 		{
    162 		case NID_sha1:
    163 		return 0x33;
    164 
    165 		case NID_sha256:
    166 		return 0x34;
    167 
    168 		case NID_sha384:
    169 		return 0x36;
    170 
    171 		case NID_sha512:
    172 		return 0x35;
    173 
    174 		}
    175 	return -1;
    176 	}
    177 
    178