1/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
2 * All rights reserved.
3 *
4 * This package is an SSL implementation written
5 * by Eric Young (eay@cryptsoft.com).
6 * The implementation was written so as to conform with Netscapes SSL.
7 *
8 * This library is free for commercial and non-commercial use as long as
9 * the following conditions are aheared to.  The following conditions
10 * apply to all code found in this distribution, be it the RC4, RSA,
11 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
12 * included with this distribution is covered by the same copyright terms
13 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
14 *
15 * Copyright remains Eric Young's, and as such any Copyright notices in
16 * the code are not to be removed.
17 * If this package is used in a product, Eric Young should be given attribution
18 * as the author of the parts of the library used.
19 * This can be in the form of a textual message at program startup or
20 * in documentation (online or textual) provided with the package.
21 *
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
25 * 1. Redistributions of source code must retain the copyright
26 *    notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 *    notice, this list of conditions and the following disclaimer in the
29 *    documentation and/or other materials provided with the distribution.
30 * 3. All advertising materials mentioning features or use of this software
31 *    must display the following acknowledgement:
32 *    "This product includes cryptographic software written by
33 *     Eric Young (eay@cryptsoft.com)"
34 *    The word 'cryptographic' can be left out if the rouines from the library
35 *    being used are not cryptographic related :-).
36 * 4. If you include any Windows specific code (or a derivative thereof) from
37 *    the apps directory (application code) you must include an acknowledgement:
38 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50 * SUCH DAMAGE.
51 *
52 * The licence and distribution terms for any publically available version or
53 * derivative of this code cannot be changed.  i.e. this code cannot simply be
54 * copied and put under another distribution licence
55 * [including the GNU Public Licence.] */
56
57#include <openssl/asn1.h>
58
59#include <string.h>
60
61#include <openssl/err.h>
62#include <openssl/mem.h>
63
64#include "../internal.h"
65
66
67int ASN1_BIT_STRING_set(ASN1_BIT_STRING *x, unsigned char *d, int len)
68{
69    return M_ASN1_BIT_STRING_set(x, d, len);
70}
71
72int i2c_ASN1_BIT_STRING(ASN1_BIT_STRING *a, unsigned char **pp)
73{
74    int ret, j, bits, len;
75    unsigned char *p, *d;
76
77    if (a == NULL)
78        return (0);
79
80    len = a->length;
81
82    if (len > 0) {
83        if (a->flags & ASN1_STRING_FLAG_BITS_LEFT) {
84            bits = (int)a->flags & 0x07;
85        } else {
86            for (; len > 0; len--) {
87                if (a->data[len - 1])
88                    break;
89            }
90            j = a->data[len - 1];
91            if (j & 0x01)
92                bits = 0;
93            else if (j & 0x02)
94                bits = 1;
95            else if (j & 0x04)
96                bits = 2;
97            else if (j & 0x08)
98                bits = 3;
99            else if (j & 0x10)
100                bits = 4;
101            else if (j & 0x20)
102                bits = 5;
103            else if (j & 0x40)
104                bits = 6;
105            else if (j & 0x80)
106                bits = 7;
107            else
108                bits = 0;       /* should not happen */
109        }
110    } else
111        bits = 0;
112
113    ret = 1 + len;
114    if (pp == NULL)
115        return (ret);
116
117    p = *pp;
118
119    *(p++) = (unsigned char)bits;
120    d = a->data;
121    OPENSSL_memcpy(p, d, len);
122    p += len;
123    if (len > 0)
124        p[-1] &= (0xff << bits);
125    *pp = p;
126    return (ret);
127}
128
129ASN1_BIT_STRING *c2i_ASN1_BIT_STRING(ASN1_BIT_STRING **a,
130                                     const unsigned char **pp, long len)
131{
132    ASN1_BIT_STRING *ret = NULL;
133    const unsigned char *p;
134    unsigned char *s;
135    int padding;
136
137    if (len < 1) {
138        OPENSSL_PUT_ERROR(ASN1, ASN1_R_STRING_TOO_SHORT);
139        goto err;
140    }
141
142    if ((a == NULL) || ((*a) == NULL)) {
143        if ((ret = M_ASN1_BIT_STRING_new()) == NULL)
144            return (NULL);
145    } else
146        ret = (*a);
147
148    p = *pp;
149    padding = *(p++);
150    if (padding > 7) {
151        OPENSSL_PUT_ERROR(ASN1, ASN1_R_INVALID_BIT_STRING_BITS_LEFT);
152        goto err;
153    }
154
155    /*
156     * We do this to preserve the settings.  If we modify the settings, via
157     * the _set_bit function, we will recalculate on output
158     */
159    ret->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07); /* clear */
160    ret->flags |= (ASN1_STRING_FLAG_BITS_LEFT | padding); /* set */
161
162    if (len-- > 1) {            /* using one because of the bits left byte */
163        s = (unsigned char *)OPENSSL_malloc((int)len);
164        if (s == NULL) {
165            OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE);
166            goto err;
167        }
168        OPENSSL_memcpy(s, p, (int)len);
169        s[len - 1] &= (0xff << padding);
170        p += len;
171    } else
172        s = NULL;
173
174    ret->length = (int)len;
175    if (ret->data != NULL)
176        OPENSSL_free(ret->data);
177    ret->data = s;
178    ret->type = V_ASN1_BIT_STRING;
179    if (a != NULL)
180        (*a) = ret;
181    *pp = p;
182    return (ret);
183 err:
184    if ((ret != NULL) && ((a == NULL) || (*a != ret)))
185        M_ASN1_BIT_STRING_free(ret);
186    return (NULL);
187}
188
189/*
190 * These next 2 functions from Goetz Babin-Ebell <babinebell@trustcenter.de>
191 */
192int ASN1_BIT_STRING_set_bit(ASN1_BIT_STRING *a, int n, int value)
193{
194    int w, v, iv;
195    unsigned char *c;
196
197    w = n / 8;
198    v = 1 << (7 - (n & 0x07));
199    iv = ~v;
200    if (!value)
201        v = 0;
202
203    if (a == NULL)
204        return 0;
205
206    a->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07); /* clear, set on write */
207
208    if ((a->length < (w + 1)) || (a->data == NULL)) {
209        if (!value)
210            return (1);         /* Don't need to set */
211        if (a->data == NULL)
212            c = (unsigned char *)OPENSSL_malloc(w + 1);
213        else
214            c = (unsigned char *)OPENSSL_realloc_clean(a->data,
215                                                       a->length, w + 1);
216        if (c == NULL) {
217            OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE);
218            return 0;
219        }
220        if (w + 1 - a->length > 0)
221            OPENSSL_memset(c + a->length, 0, w + 1 - a->length);
222        a->data = c;
223        a->length = w + 1;
224    }
225    a->data[w] = ((a->data[w]) & iv) | v;
226    while ((a->length > 0) && (a->data[a->length - 1] == 0))
227        a->length--;
228    return (1);
229}
230
231int ASN1_BIT_STRING_get_bit(ASN1_BIT_STRING *a, int n)
232{
233    int w, v;
234
235    w = n / 8;
236    v = 1 << (7 - (n & 0x07));
237    if ((a == NULL) || (a->length < (w + 1)) || (a->data == NULL))
238        return (0);
239    return ((a->data[w] & v) != 0);
240}
241
242/*
243 * Checks if the given bit string contains only bits specified by
244 * the flags vector. Returns 0 if there is at least one bit set in 'a'
245 * which is not specified in 'flags', 1 otherwise.
246 * 'len' is the length of 'flags'.
247 */
248int ASN1_BIT_STRING_check(ASN1_BIT_STRING *a,
249                          unsigned char *flags, int flags_len)
250{
251    int i, ok;
252    /* Check if there is one bit set at all. */
253    if (!a || !a->data)
254        return 1;
255
256    /*
257     * Check each byte of the internal representation of the bit string.
258     */
259    ok = 1;
260    for (i = 0; i < a->length && ok; ++i) {
261        unsigned char mask = i < flags_len ? ~flags[i] : 0xff;
262        /* We are done if there is an unneeded bit set. */
263        ok = (a->data[i] & mask) == 0;
264    }
265    return ok;
266}
267