1/* crypto/asn1/a_bitstr.c */
2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@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@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@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@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
63int ASN1_BIT_STRING_set(ASN1_BIT_STRING *x, unsigned char *d, int len)
64{ return M_ASN1_BIT_STRING_set(x, d, len); }
65
66int 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
116ASN1_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);
167err:
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@trustcenter.de>
175 */
176int 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
215int 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 */
232int 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