1 /* $OpenBSD: a_bitstr.c,v 1.36 2022/05/17 09:17:20 tb Exp $ */
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 <limits.h>
60 #include <stdio.h>
61 #include <string.h>
62
63 #include <openssl/asn1.h>
64 #include <openssl/asn1t.h>
65 #include <openssl/conf.h>
66 #include <openssl/err.h>
67 #include <openssl/x509v3.h>
68
69 #include "bytestring.h"
70
71 const ASN1_ITEM ASN1_BIT_STRING_it = {
72 .itype = ASN1_ITYPE_PRIMITIVE,
73 .utype = V_ASN1_BIT_STRING,
74 .sname = "ASN1_BIT_STRING",
75 };
76
77 ASN1_BIT_STRING *
ASN1_BIT_STRING_new(void)78 ASN1_BIT_STRING_new(void)
79 {
80 return (ASN1_BIT_STRING *)ASN1_item_new(&ASN1_BIT_STRING_it);
81 }
82
83 void
ASN1_BIT_STRING_free(ASN1_BIT_STRING * a)84 ASN1_BIT_STRING_free(ASN1_BIT_STRING *a)
85 {
86 ASN1_item_free((ASN1_VALUE *)a, &ASN1_BIT_STRING_it);
87 }
88
89 static void
asn1_abs_clear_unused_bits(ASN1_BIT_STRING * abs)90 asn1_abs_clear_unused_bits(ASN1_BIT_STRING *abs)
91 {
92 abs->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
93 }
94
95 int
asn1_abs_set_unused_bits(ASN1_BIT_STRING * abs,uint8_t unused_bits)96 asn1_abs_set_unused_bits(ASN1_BIT_STRING *abs, uint8_t unused_bits)
97 {
98 if (unused_bits > 7)
99 return 0;
100
101 asn1_abs_clear_unused_bits(abs);
102
103 abs->flags |= ASN1_STRING_FLAG_BITS_LEFT | unused_bits;
104
105 return 1;
106 }
107
108 int
ASN1_BIT_STRING_set(ASN1_BIT_STRING * x,unsigned char * d,int len)109 ASN1_BIT_STRING_set(ASN1_BIT_STRING *x, unsigned char *d, int len)
110 {
111 return ASN1_STRING_set(x, d, len);
112 }
113
114 int
ASN1_BIT_STRING_set_bit(ASN1_BIT_STRING * a,int n,int value)115 ASN1_BIT_STRING_set_bit(ASN1_BIT_STRING *a, int n, int value)
116 {
117 int w, v, iv;
118 unsigned char *c;
119
120 w = n/8;
121 v = 1 << (7 - (n & 0x07));
122 iv = ~v;
123 if (!value)
124 v = 0;
125
126 if (a == NULL)
127 return 0;
128
129 asn1_abs_clear_unused_bits(a);
130
131 if ((a->length < (w + 1)) || (a->data == NULL)) {
132 if (!value)
133 return(1); /* Don't need to set */
134 if ((c = recallocarray(a->data, a->length, w + 1, 1)) == NULL) {
135 ASN1error(ERR_R_MALLOC_FAILURE);
136 return 0;
137 }
138 a->data = c;
139 a->length = w + 1;
140 }
141 a->data[w] = ((a->data[w]) & iv) | v;
142 while ((a->length > 0) && (a->data[a->length - 1] == 0))
143 a->length--;
144
145 return (1);
146 }
147
148 int
ASN1_BIT_STRING_get_bit(const ASN1_BIT_STRING * a,int n)149 ASN1_BIT_STRING_get_bit(const ASN1_BIT_STRING *a, int n)
150 {
151 int w, v;
152
153 w = n / 8;
154 v = 1 << (7 - (n & 0x07));
155 if ((a == NULL) || (a->length < (w + 1)) || (a->data == NULL))
156 return (0);
157 return ((a->data[w] & v) != 0);
158 }
159
160 /*
161 * Checks if the given bit string contains only bits specified by
162 * the flags vector. Returns 0 if there is at least one bit set in 'a'
163 * which is not specified in 'flags', 1 otherwise.
164 * 'len' is the length of 'flags'.
165 */
166 int
ASN1_BIT_STRING_check(const ASN1_BIT_STRING * a,const unsigned char * flags,int flags_len)167 ASN1_BIT_STRING_check(const ASN1_BIT_STRING *a, const unsigned char *flags,
168 int flags_len)
169 {
170 int i, ok;
171
172 /* Check if there is one bit set at all. */
173 if (!a || !a->data)
174 return 1;
175
176 /* Check each byte of the internal representation of the bit string. */
177 ok = 1;
178 for (i = 0; i < a->length && ok; ++i) {
179 unsigned char mask = i < flags_len ? ~flags[i] : 0xff;
180 /* We are done if there is an unneeded bit set. */
181 ok = (a->data[i] & mask) == 0;
182 }
183 return ok;
184 }
185
186 int
ASN1_BIT_STRING_name_print(BIO * out,ASN1_BIT_STRING * bs,BIT_STRING_BITNAME * tbl,int indent)187 ASN1_BIT_STRING_name_print(BIO *out, ASN1_BIT_STRING *bs,
188 BIT_STRING_BITNAME *tbl, int indent)
189 {
190 BIT_STRING_BITNAME *bnam;
191 char first = 1;
192
193 BIO_printf(out, "%*s", indent, "");
194 for (bnam = tbl; bnam->lname; bnam++) {
195 if (ASN1_BIT_STRING_get_bit(bs, bnam->bitnum)) {
196 if (!first)
197 BIO_puts(out, ", ");
198 BIO_puts(out, bnam->lname);
199 first = 0;
200 }
201 }
202 BIO_puts(out, "\n");
203 return 1;
204 }
205
206 int
ASN1_BIT_STRING_set_asc(ASN1_BIT_STRING * bs,const char * name,int value,BIT_STRING_BITNAME * tbl)207 ASN1_BIT_STRING_set_asc(ASN1_BIT_STRING *bs, const char *name, int value,
208 BIT_STRING_BITNAME *tbl)
209 {
210 int bitnum;
211
212 bitnum = ASN1_BIT_STRING_num_asc(name, tbl);
213 if (bitnum < 0)
214 return 0;
215 if (bs) {
216 if (!ASN1_BIT_STRING_set_bit(bs, bitnum, value))
217 return 0;
218 }
219 return 1;
220 }
221
222 int
ASN1_BIT_STRING_num_asc(const char * name,BIT_STRING_BITNAME * tbl)223 ASN1_BIT_STRING_num_asc(const char *name, BIT_STRING_BITNAME *tbl)
224 {
225 BIT_STRING_BITNAME *bnam;
226
227 for (bnam = tbl; bnam->lname; bnam++) {
228 if (!strcmp(bnam->sname, name) ||
229 !strcmp(bnam->lname, name))
230 return bnam->bitnum;
231 }
232 return -1;
233 }
234
235 int
i2c_ASN1_BIT_STRING(ASN1_BIT_STRING * a,unsigned char ** pp)236 i2c_ASN1_BIT_STRING(ASN1_BIT_STRING *a, unsigned char **pp)
237 {
238 int ret, j, bits, len;
239 unsigned char *p, *d;
240
241 if (a == NULL)
242 return (0);
243
244 len = a->length;
245
246 if (len > 0) {
247 if (a->flags & ASN1_STRING_FLAG_BITS_LEFT) {
248 bits = (int)a->flags & 0x07;
249 } else {
250 for (; len > 0; len--) {
251 if (a->data[len - 1])
252 break;
253 }
254 j = a->data[len - 1];
255 if (j & 0x01)
256 bits = 0;
257 else if (j & 0x02)
258 bits = 1;
259 else if (j & 0x04)
260 bits = 2;
261 else if (j & 0x08)
262 bits = 3;
263 else if (j & 0x10)
264 bits = 4;
265 else if (j & 0x20)
266 bits = 5;
267 else if (j & 0x40)
268 bits = 6;
269 else if (j & 0x80)
270 bits = 7;
271 else
272 bits = 0; /* should not happen */
273 }
274 } else
275 bits = 0;
276
277 ret = 1 + len;
278 if (pp == NULL)
279 return (ret);
280
281 p= *pp;
282
283 *(p++) = (unsigned char)bits;
284 d = a->data;
285 if (len > 0) {
286 memcpy(p, d, len);
287 p += len;
288 p[-1] &= 0xff << bits;
289 }
290 *pp = p;
291 return (ret);
292 }
293
294 int
c2i_ASN1_BIT_STRING_cbs(ASN1_BIT_STRING ** out_abs,CBS * cbs)295 c2i_ASN1_BIT_STRING_cbs(ASN1_BIT_STRING **out_abs, CBS *cbs)
296 {
297 ASN1_BIT_STRING *abs = NULL;
298 uint8_t *data = NULL;
299 size_t data_len = 0;
300 uint8_t unused_bits;
301 int ret = 0;
302
303 if (out_abs == NULL)
304 goto err;
305
306 if (*out_abs != NULL) {
307 ASN1_BIT_STRING_free(*out_abs);
308 *out_abs = NULL;
309 }
310
311 if (!CBS_get_u8(cbs, &unused_bits)) {
312 ASN1error(ASN1_R_STRING_TOO_SHORT);
313 goto err;
314 }
315
316 if (!CBS_stow(cbs, &data, &data_len))
317 goto err;
318 if (data_len > INT_MAX)
319 goto err;
320
321 if ((abs = ASN1_BIT_STRING_new()) == NULL)
322 goto err;
323
324 abs->data = data;
325 abs->length = (int)data_len;
326 data = NULL;
327
328 /*
329 * We do this to preserve the settings. If we modify the settings,
330 * via the _set_bit function, we will recalculate on output.
331 */
332 if (!asn1_abs_set_unused_bits(abs, unused_bits)) {
333 ASN1error(ASN1_R_INVALID_BIT_STRING_BITS_LEFT);
334 goto err;
335 }
336 if (abs->length > 0)
337 abs->data[abs->length - 1] &= 0xff << unused_bits;
338
339 *out_abs = abs;
340 abs = NULL;
341
342 ret = 1;
343
344 err:
345 ASN1_BIT_STRING_free(abs);
346 freezero(data, data_len);
347
348 return ret;
349 }
350
351 ASN1_BIT_STRING *
c2i_ASN1_BIT_STRING(ASN1_BIT_STRING ** out_abs,const unsigned char ** pp,long len)352 c2i_ASN1_BIT_STRING(ASN1_BIT_STRING **out_abs, const unsigned char **pp, long len)
353 {
354 ASN1_BIT_STRING *abs = NULL;
355 CBS content;
356
357 if (out_abs != NULL) {
358 ASN1_BIT_STRING_free(*out_abs);
359 *out_abs = NULL;
360 }
361
362 if (len < 0) {
363 ASN1error(ASN1_R_LENGTH_ERROR);
364 return NULL;
365 }
366
367 CBS_init(&content, *pp, len);
368
369 if (!c2i_ASN1_BIT_STRING_cbs(&abs, &content))
370 return NULL;
371
372 *pp = CBS_data(&content);
373
374 if (out_abs != NULL)
375 *out_abs = abs;
376
377 return abs;
378 }
379
380 int
i2d_ASN1_BIT_STRING(ASN1_BIT_STRING * a,unsigned char ** out)381 i2d_ASN1_BIT_STRING(ASN1_BIT_STRING *a, unsigned char **out)
382 {
383 return ASN1_item_i2d((ASN1_VALUE *)a, out, &ASN1_BIT_STRING_it);
384 }
385
386 ASN1_BIT_STRING *
d2i_ASN1_BIT_STRING(ASN1_BIT_STRING ** a,const unsigned char ** in,long len)387 d2i_ASN1_BIT_STRING(ASN1_BIT_STRING **a, const unsigned char **in, long len)
388 {
389 return (ASN1_BIT_STRING *)ASN1_item_d2i((ASN1_VALUE **)a, in, len,
390 &ASN1_BIT_STRING_it);
391 }
392