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 <limits.h>
60#include <string.h>
61
62#include <openssl/err.h>
63#include <openssl/mem.h>
64
65#include "../internal.h"
66
67
68int ASN1_BIT_STRING_set(ASN1_BIT_STRING *x, unsigned char *d, int len)
69{
70    return M_ASN1_BIT_STRING_set(x, d, len);
71}
72
73int i2c_ASN1_BIT_STRING(ASN1_BIT_STRING *a, unsigned char **pp)
74{
75    int ret, j, bits, len;
76    unsigned char *p, *d;
77
78    if (a == NULL)
79        return (0);
80
81    len = a->length;
82
83    if (len > 0) {
84        if (a->flags & ASN1_STRING_FLAG_BITS_LEFT) {
85            bits = (int)a->flags & 0x07;
86        } else {
87            for (; len > 0; len--) {
88                if (a->data[len - 1])
89                    break;
90            }
91            j = a->data[len - 1];
92            if (j & 0x01)
93                bits = 0;
94            else if (j & 0x02)
95                bits = 1;
96            else if (j & 0x04)
97                bits = 2;
98            else if (j & 0x08)
99                bits = 3;
100            else if (j & 0x10)
101                bits = 4;
102            else if (j & 0x20)
103                bits = 5;
104            else if (j & 0x40)
105                bits = 6;
106            else if (j & 0x80)
107                bits = 7;
108            else
109                bits = 0;       /* should not happen */
110        }
111    } else
112        bits = 0;
113
114    ret = 1 + len;
115    if (pp == NULL)
116        return (ret);
117
118    p = *pp;
119
120    *(p++) = (unsigned char)bits;
121    d = a->data;
122    OPENSSL_memcpy(p, d, len);
123    p += len;
124    if (len > 0)
125        p[-1] &= (0xff << bits);
126    *pp = p;
127    return (ret);
128}
129
130ASN1_BIT_STRING *c2i_ASN1_BIT_STRING(ASN1_BIT_STRING **a,
131                                     const unsigned char **pp, long len)
132{
133    ASN1_BIT_STRING *ret = NULL;
134    const unsigned char *p;
135    unsigned char *s;
136    int padding;
137
138    if (len < 1) {
139        OPENSSL_PUT_ERROR(ASN1, ASN1_R_STRING_TOO_SHORT);
140        goto err;
141    }
142
143    if (len > INT_MAX) {
144      OPENSSL_PUT_ERROR(ASN1, ASN1_R_STRING_TOO_LONG);
145      goto err;
146    }
147
148    if ((a == NULL) || ((*a) == NULL)) {
149        if ((ret = M_ASN1_BIT_STRING_new()) == NULL)
150            return (NULL);
151    } else
152        ret = (*a);
153
154    p = *pp;
155    padding = *(p++);
156    if (padding > 7) {
157        OPENSSL_PUT_ERROR(ASN1, ASN1_R_INVALID_BIT_STRING_BITS_LEFT);
158        goto err;
159    }
160
161    /*
162     * We do this to preserve the settings.  If we modify the settings, via
163     * the _set_bit function, we will recalculate on output
164     */
165    ret->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07); /* clear */
166    ret->flags |= (ASN1_STRING_FLAG_BITS_LEFT | padding); /* set */
167
168    if (len-- > 1) {            /* using one because of the bits left byte */
169        s = (unsigned char *)OPENSSL_malloc((int)len);
170        if (s == NULL) {
171            OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE);
172            goto err;
173        }
174        OPENSSL_memcpy(s, p, (int)len);
175        s[len - 1] &= (0xff << padding);
176        p += len;
177    } else
178        s = NULL;
179
180    ret->length = (int)len;
181    if (ret->data != NULL)
182        OPENSSL_free(ret->data);
183    ret->data = s;
184    ret->type = V_ASN1_BIT_STRING;
185    if (a != NULL)
186        (*a) = ret;
187    *pp = p;
188    return (ret);
189 err:
190    if ((ret != NULL) && ((a == NULL) || (*a != ret)))
191        M_ASN1_BIT_STRING_free(ret);
192    return (NULL);
193}
194
195/*
196 * These next 2 functions from Goetz Babin-Ebell <babinebell@trustcenter.de>
197 */
198int ASN1_BIT_STRING_set_bit(ASN1_BIT_STRING *a, int n, int value)
199{
200    int w, v, iv;
201    unsigned char *c;
202
203    w = n / 8;
204    v = 1 << (7 - (n & 0x07));
205    iv = ~v;
206    if (!value)
207        v = 0;
208
209    if (a == NULL)
210        return 0;
211
212    a->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07); /* clear, set on write */
213
214    if ((a->length < (w + 1)) || (a->data == NULL)) {
215        if (!value)
216            return (1);         /* Don't need to set */
217        if (a->data == NULL)
218            c = (unsigned char *)OPENSSL_malloc(w + 1);
219        else
220            c = (unsigned char *)OPENSSL_realloc(a->data, w + 1);
221        if (c == NULL) {
222            OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE);
223            return 0;
224        }
225        if (w + 1 - a->length > 0)
226            OPENSSL_memset(c + a->length, 0, w + 1 - a->length);
227        a->data = c;
228        a->length = w + 1;
229    }
230    a->data[w] = ((a->data[w]) & iv) | v;
231    while ((a->length > 0) && (a->data[a->length - 1] == 0))
232        a->length--;
233    return (1);
234}
235
236int ASN1_BIT_STRING_get_bit(ASN1_BIT_STRING *a, int n)
237{
238    int w, v;
239
240    w = n / 8;
241    v = 1 << (7 - (n & 0x07));
242    if ((a == NULL) || (a->length < (w + 1)) || (a->data == NULL))
243        return (0);
244    return ((a->data[w] & v) != 0);
245}
246
247/*
248 * Checks if the given bit string contains only bits specified by
249 * the flags vector. Returns 0 if there is at least one bit set in 'a'
250 * which is not specified in 'flags', 1 otherwise.
251 * 'len' is the length of 'flags'.
252 */
253int ASN1_BIT_STRING_check(ASN1_BIT_STRING *a,
254                          unsigned char *flags, int flags_len)
255{
256    int i, ok;
257    /* Check if there is one bit set at all. */
258    if (!a || !a->data)
259        return 1;
260
261    /*
262     * Check each byte of the internal representation of the bit string.
263     */
264    ok = 1;
265    for (i = 0; i < a->length && ok; ++i) {
266        unsigned char mask = i < flags_len ? ~flags[i] : 0xff;
267        /* We are done if there is an unneeded bit set. */
268        ok = (a->data[i] & mask) == 0;
269    }
270    return ok;
271}
272