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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 
ASN1_BIT_STRING_set(ASN1_BIT_STRING * x,unsigned char * d,int len)67 int 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 
i2c_ASN1_BIT_STRING(ASN1_BIT_STRING * a,unsigned char ** pp)72 int 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 
c2i_ASN1_BIT_STRING(ASN1_BIT_STRING ** a,const unsigned char ** pp,long len)129 ASN1_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  */
ASN1_BIT_STRING_set_bit(ASN1_BIT_STRING * a,int n,int value)192 int 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 
ASN1_BIT_STRING_get_bit(ASN1_BIT_STRING * a,int n)231 int 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  */
ASN1_BIT_STRING_check(ASN1_BIT_STRING * a,unsigned char * flags,int flags_len)248 int 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