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      1 /* crypto/asn1/a_bitstr.c */
      2 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com)
      3  * All rights reserved.
      4  *
      5  * This package is an SSL implementation written
      6  * by Eric Young (eay (at) cryptsoft.com).
      7  * The implementation was written so as to conform with Netscapes SSL.
      8  *
      9  * This library is free for commercial and non-commercial use as long as
     10  * the following conditions are aheared to.  The following conditions
     11  * apply to all code found in this distribution, be it the RC4, RSA,
     12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
     13  * included with this distribution is covered by the same copyright terms
     14  * except that the holder is Tim Hudson (tjh (at) cryptsoft.com).
     15  *
     16  * Copyright remains Eric Young's, and as such any Copyright notices in
     17  * the code are not to be removed.
     18  * If this package is used in a product, Eric Young should be given attribution
     19  * as the author of the parts of the library used.
     20  * This can be in the form of a textual message at program startup or
     21  * in documentation (online or textual) provided with the package.
     22  *
     23  * Redistribution and use in source and binary forms, with or without
     24  * modification, are permitted provided that the following conditions
     25  * are met:
     26  * 1. Redistributions of source code must retain the copyright
     27  *    notice, this list of conditions and the following disclaimer.
     28  * 2. Redistributions in binary form must reproduce the above copyright
     29  *    notice, this list of conditions and the following disclaimer in the
     30  *    documentation and/or other materials provided with the distribution.
     31  * 3. All advertising materials mentioning features or use of this software
     32  *    must display the following acknowledgement:
     33  *    "This product includes cryptographic software written by
     34  *     Eric Young (eay (at) cryptsoft.com)"
     35  *    The word 'cryptographic' can be left out if the rouines from the library
     36  *    being used are not cryptographic related :-).
     37  * 4. If you include any Windows specific code (or a derivative thereof) from
     38  *    the apps directory (application code) you must include an acknowledgement:
     39  *    "This product includes software written by Tim Hudson (tjh (at) cryptsoft.com)"
     40  *
     41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
     42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     51  * SUCH DAMAGE.
     52  *
     53  * The licence and distribution terms for any publically available version or
     54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
     55  * copied and put under another distribution licence
     56  * [including the GNU Public Licence.]
     57  */
     58 
     59 #include <stdio.h>
     60 #include "cryptlib.h"
     61 #include <openssl/asn1.h>
     62 
     63 int ASN1_BIT_STRING_set(ASN1_BIT_STRING *x, unsigned char *d, int len)
     64 { return M_ASN1_BIT_STRING_set(x, d, len); }
     65 
     66 int i2c_ASN1_BIT_STRING(ASN1_BIT_STRING *a, unsigned char **pp)
     67 	{
     68 	int ret,j,bits,len;
     69 	unsigned char *p,*d;
     70 
     71 	if (a == NULL) return(0);
     72 
     73 	len=a->length;
     74 
     75 	if (len > 0)
     76 		{
     77 		if (a->flags & ASN1_STRING_FLAG_BITS_LEFT)
     78 			{
     79 			bits=(int)a->flags&0x07;
     80 			}
     81 		else
     82 			{
     83 			for ( ; len > 0; len--)
     84 				{
     85 				if (a->data[len-1]) break;
     86 				}
     87 			j=a->data[len-1];
     88 			if      (j & 0x01) bits=0;
     89 			else if (j & 0x02) bits=1;
     90 			else if (j & 0x04) bits=2;
     91 			else if (j & 0x08) bits=3;
     92 			else if (j & 0x10) bits=4;
     93 			else if (j & 0x20) bits=5;
     94 			else if (j & 0x40) bits=6;
     95 			else if (j & 0x80) bits=7;
     96 			else bits=0; /* should not happen */
     97 			}
     98 		}
     99 	else
    100 		bits=0;
    101 
    102 	ret=1+len;
    103 	if (pp == NULL) return(ret);
    104 
    105 	p= *pp;
    106 
    107 	*(p++)=(unsigned char)bits;
    108 	d=a->data;
    109 	memcpy(p,d,len);
    110 	p+=len;
    111 	if (len > 0) p[-1]&=(0xff<<bits);
    112 	*pp=p;
    113 	return(ret);
    114 	}
    115 
    116 ASN1_BIT_STRING *c2i_ASN1_BIT_STRING(ASN1_BIT_STRING **a,
    117 	const unsigned char **pp, long len)
    118 	{
    119 	ASN1_BIT_STRING *ret=NULL;
    120 	const unsigned char *p;
    121 	unsigned char *s;
    122 	int i;
    123 
    124 	if (len < 1)
    125 		{
    126 		i=ASN1_R_STRING_TOO_SHORT;
    127 		goto err;
    128 		}
    129 
    130 	if ((a == NULL) || ((*a) == NULL))
    131 		{
    132 		if ((ret=M_ASN1_BIT_STRING_new()) == NULL) return(NULL);
    133 		}
    134 	else
    135 		ret=(*a);
    136 
    137 	p= *pp;
    138 	i= *(p++);
    139 	/* We do this to preserve the settings.  If we modify
    140 	 * the settings, via the _set_bit function, we will recalculate
    141 	 * on output */
    142 	ret->flags&= ~(ASN1_STRING_FLAG_BITS_LEFT|0x07); /* clear */
    143 	ret->flags|=(ASN1_STRING_FLAG_BITS_LEFT|(i&0x07)); /* set */
    144 
    145 	if (len-- > 1) /* using one because of the bits left byte */
    146 		{
    147 		s=(unsigned char *)OPENSSL_malloc((int)len);
    148 		if (s == NULL)
    149 			{
    150 			i=ERR_R_MALLOC_FAILURE;
    151 			goto err;
    152 			}
    153 		memcpy(s,p,(int)len);
    154 		s[len-1]&=(0xff<<i);
    155 		p+=len;
    156 		}
    157 	else
    158 		s=NULL;
    159 
    160 	ret->length=(int)len;
    161 	if (ret->data != NULL) OPENSSL_free(ret->data);
    162 	ret->data=s;
    163 	ret->type=V_ASN1_BIT_STRING;
    164 	if (a != NULL) (*a)=ret;
    165 	*pp=p;
    166 	return(ret);
    167 err:
    168 	ASN1err(ASN1_F_C2I_ASN1_BIT_STRING,i);
    169 	if ((ret != NULL) && ((a == NULL) || (*a != ret)))
    170 		M_ASN1_BIT_STRING_free(ret);
    171 	return(NULL);
    172 	}
    173 
    174 /* These next 2 functions from Goetz Babin-Ebell <babinebell (at) trustcenter.de>
    175  */
    176 int ASN1_BIT_STRING_set_bit(ASN1_BIT_STRING *a, int n, int value)
    177 	{
    178 	int w,v,iv;
    179 	unsigned char *c;
    180 
    181 	w=n/8;
    182 	v=1<<(7-(n&0x07));
    183 	iv= ~v;
    184 	if (!value) v=0;
    185 
    186 	if (a == NULL)
    187 		return 0;
    188 
    189 	a->flags&= ~(ASN1_STRING_FLAG_BITS_LEFT|0x07); /* clear, set on write */
    190 
    191 	if ((a->length < (w+1)) || (a->data == NULL))
    192 		{
    193 		if (!value) return(1); /* Don't need to set */
    194 		if (a->data == NULL)
    195 			c=(unsigned char *)OPENSSL_malloc(w+1);
    196 		else
    197 			c=(unsigned char *)OPENSSL_realloc_clean(a->data,
    198 								 a->length,
    199 								 w+1);
    200 		if (c == NULL)
    201 			{
    202 			ASN1err(ASN1_F_ASN1_BIT_STRING_SET_BIT,ERR_R_MALLOC_FAILURE);
    203 			return 0;
    204 			}
    205   		if (w+1-a->length > 0) memset(c+a->length, 0, w+1-a->length);
    206 		a->data=c;
    207 		a->length=w+1;
    208 	}
    209 	a->data[w]=((a->data[w])&iv)|v;
    210 	while ((a->length > 0) && (a->data[a->length-1] == 0))
    211 		a->length--;
    212 	return(1);
    213 	}
    214 
    215 int ASN1_BIT_STRING_get_bit(ASN1_BIT_STRING *a, int n)
    216 	{
    217 	int w,v;
    218 
    219 	w=n/8;
    220 	v=1<<(7-(n&0x07));
    221 	if ((a == NULL) || (a->length < (w+1)) || (a->data == NULL))
    222 		return(0);
    223 	return((a->data[w]&v) != 0);
    224 	}
    225 
    226 /*
    227  * Checks if the given bit string contains only bits specified by
    228  * the flags vector. Returns 0 if there is at least one bit set in 'a'
    229  * which is not specified in 'flags', 1 otherwise.
    230  * 'len' is the length of 'flags'.
    231  */
    232 int ASN1_BIT_STRING_check(ASN1_BIT_STRING *a,
    233 			  unsigned char *flags, int flags_len)
    234 	{
    235 	int i, ok;
    236 	/* Check if there is one bit set at all. */
    237 	if (!a || !a->data) return 1;
    238 
    239 	/* Check each byte of the internal representation of the bit string. */
    240 	ok = 1;
    241 	for (i = 0; i < a->length && ok; ++i)
    242 		{
    243 		unsigned char mask = i < flags_len ? ~flags[i] : 0xff;
    244 		/* We are done if there is an unneeded bit set. */
    245 		ok = (a->data[i] & mask) == 0;
    246 		}
    247 	return ok;
    248 	}
    249