xref: /openbsd-src/lib/libcrypto/asn1/asn1_lib.c (revision a8913c44aee6c78b4770e56ab6afb429afabee6d)
1 /* $OpenBSD: asn1_lib.c,v 1.29 2014/07/10 13:58:22 jsing 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 "cryptlib.h"
64 #include <openssl/asn1.h>
65 #include <openssl/asn1_mac.h>
66 
67 static int asn1_get_length(const unsigned char **pp, int *inf, long *rl, int max);
68 static void asn1_put_length(unsigned char **pp, int length);
69 
70 static int
71 _asn1_check_infinite_end(const unsigned char **p, long len)
72 {
73 	/* If there is 0 or 1 byte left, the length check should pick
74 	 * things up */
75 	if (len <= 0)
76 		return (1);
77 	else if ((len >= 2) && ((*p)[0] == 0) && ((*p)[1] == 0)) {
78 		(*p) += 2;
79 		return (1);
80 	}
81 	return (0);
82 }
83 
84 int
85 ASN1_check_infinite_end(unsigned char **p, long len)
86 {
87 	return _asn1_check_infinite_end((const unsigned char **)p, len);
88 }
89 
90 int
91 ASN1_const_check_infinite_end(const unsigned char **p, long len)
92 {
93 	return _asn1_check_infinite_end(p, len);
94 }
95 
96 int
97 ASN1_get_object(const unsigned char **pp, long *plength, int *ptag,
98     int *pclass, long omax)
99 {
100 	int i, ret;
101 	long l;
102 	const unsigned char *p= *pp;
103 	int tag, xclass, inf;
104 	long max = omax;
105 
106 	if (!max)
107 		goto err;
108 	ret = (*p & V_ASN1_CONSTRUCTED);
109 	xclass = (*p & V_ASN1_PRIVATE);
110 	i= *p & V_ASN1_PRIMITIVE_TAG;
111 	if (i == V_ASN1_PRIMITIVE_TAG) {		/* high-tag */
112 		p++;
113 		if (--max == 0)
114 			goto err;
115 		l = 0;
116 		while (*p & 0x80) {
117 			l <<= 7L;
118 			l |= *(p++) & 0x7f;
119 			if (--max == 0)
120 				goto err;
121 			if (l > (INT_MAX >> 7L))
122 				goto err;
123 		}
124 		l <<= 7L;
125 		l |= *(p++) & 0x7f;
126 		tag = (int)l;
127 		if (--max == 0)
128 			goto err;
129 	} else {
130 		tag = i;
131 		p++;
132 		if (--max == 0)
133 			goto err;
134 	}
135 	*ptag = tag;
136 	*pclass = xclass;
137 	if (!asn1_get_length(&p, &inf, plength, (int)max))
138 		goto err;
139 
140 #if 0
141 	fprintf(stderr, "p=%d + *plength=%ld > omax=%ld + *pp=%d  (%d > %d)\n",
142 	    (int)p, *plength, omax, (int)*pp, (int)(p+ *plength),
143 	    (int)(omax+ *pp));
144 
145 #endif
146 	if (*plength > (omax - (p - *pp))) {
147 		ASN1err(ASN1_F_ASN1_GET_OBJECT, ASN1_R_TOO_LONG);
148 		/* Set this so that even if things are not long enough
149 		 * the values are set correctly */
150 		ret |= 0x80;
151 	}
152 	*pp = p;
153 	return (ret | inf);
154 
155 err:
156 	ASN1err(ASN1_F_ASN1_GET_OBJECT, ASN1_R_HEADER_TOO_LONG);
157 	return (0x80);
158 }
159 
160 static int
161 asn1_get_length(const unsigned char **pp, int *inf, long *rl, int max)
162 {
163 	const unsigned char *p= *pp;
164 	unsigned long ret = 0;
165 	unsigned int i;
166 
167 	if (max-- < 1)
168 		return (0);
169 	if (*p == 0x80) {
170 		*inf = 1;
171 		ret = 0;
172 		p++;
173 	} else {
174 		*inf = 0;
175 		i= *p & 0x7f;
176 		if (*(p++) & 0x80) {
177 			if (i > sizeof(long))
178 				return 0;
179 			if (max-- == 0)
180 				return (0);
181 			while (i-- > 0) {
182 				ret <<= 8L;
183 				ret |= *(p++);
184 				if (max-- == 0)
185 					return (0);
186 			}
187 		} else
188 			ret = i;
189 	}
190 	if (ret > LONG_MAX)
191 		return 0;
192 	*pp = p;
193 	*rl = (long)ret;
194 	return (1);
195 }
196 
197 /* class 0 is constructed
198  * constructed == 2 for indefinite length constructed */
199 void
200 ASN1_put_object(unsigned char **pp, int constructed, int length, int tag,
201     int xclass)
202 {
203 	unsigned char *p= *pp;
204 	int i, ttag;
205 
206 	i = (constructed) ? V_ASN1_CONSTRUCTED : 0;
207 	i |= (xclass & V_ASN1_PRIVATE);
208 	if (tag < 31)
209 		*(p++) = i | (tag & V_ASN1_PRIMITIVE_TAG);
210 	else {
211 		*(p++) = i | V_ASN1_PRIMITIVE_TAG;
212 		for(i = 0, ttag = tag; ttag > 0; i++)
213 			ttag >>= 7;
214 		ttag = i;
215 		while (i-- > 0) {
216 			p[i] = tag & 0x7f;
217 			if (i != (ttag - 1))
218 				p[i] |= 0x80;
219 			tag >>= 7;
220 		}
221 		p += ttag;
222 	}
223 	if (constructed == 2)
224 		*(p++) = 0x80;
225 	else
226 		asn1_put_length(&p, length);
227 	*pp = p;
228 }
229 
230 int
231 ASN1_put_eoc(unsigned char **pp)
232 {
233 	unsigned char *p = *pp;
234 
235 	*p++ = 0;
236 	*p++ = 0;
237 	*pp = p;
238 	return 2;
239 }
240 
241 static void
242 asn1_put_length(unsigned char **pp, int length)
243 {
244 	unsigned char *p= *pp;
245 
246 	int i, l;
247 	if (length <= 127)
248 		*(p++) = (unsigned char)length;
249 	else {
250 		l = length;
251 		for (i = 0; l > 0; i++)
252 			l >>= 8;
253 		*(p++) = i | 0x80;
254 		l = i;
255 		while (i-- > 0) {
256 			p[i] = length & 0xff;
257 			length >>= 8;
258 		}
259 		p += l;
260 	}
261 	*pp = p;
262 }
263 
264 int
265 ASN1_object_size(int constructed, int length, int tag)
266 {
267 	int ret;
268 
269 	ret = length;
270 	ret++;
271 	if (tag >= 31) {
272 		while (tag > 0) {
273 			tag >>= 7;
274 			ret++;
275 		}
276 	}
277 	if (constructed == 2)
278 		return ret + 3;
279 	ret++;
280 	if (length > 127) {
281 		while (length > 0) {
282 			length >>= 8;
283 			ret++;
284 		}
285 	}
286 	return (ret);
287 }
288 
289 static int
290 _asn1_Finish(ASN1_const_CTX *c)
291 {
292 	if ((c->inf == (1|V_ASN1_CONSTRUCTED)) && (!c->eos)) {
293 		if (!ASN1_const_check_infinite_end(&c->p, c->slen)) {
294 			c->error = ERR_R_MISSING_ASN1_EOS;
295 			return (0);
296 		}
297 	}
298 	if (((c->slen != 0) && !(c->inf & 1)) ||
299 	    ((c->slen < 0) && (c->inf & 1))) {
300 		c->error = ERR_R_ASN1_LENGTH_MISMATCH;
301 		return (0);
302 	}
303 	return (1);
304 }
305 
306 int
307 asn1_Finish(ASN1_CTX *c)
308 {
309 	return _asn1_Finish((ASN1_const_CTX *)c);
310 }
311 
312 int
313 asn1_const_Finish(ASN1_const_CTX *c)
314 {
315 	return _asn1_Finish(c);
316 }
317 
318 int
319 asn1_GetSequence(ASN1_const_CTX *c, long *length)
320 {
321 	const unsigned char *q;
322 
323 	q = c->p;
324 	c->inf = ASN1_get_object(&(c->p), &(c->slen), &(c->tag), &(c->xclass),
325 	    *length);
326 	if (c->inf & 0x80) {
327 		c->error = ERR_R_BAD_GET_ASN1_OBJECT_CALL;
328 		return (0);
329 	}
330 	if (c->tag != V_ASN1_SEQUENCE) {
331 		c->error = ERR_R_EXPECTING_AN_ASN1_SEQUENCE;
332 		return (0);
333 	}
334 	(*length) -= (c->p - q);
335 	if (c->max && (*length < 0)) {
336 		c->error = ERR_R_ASN1_LENGTH_MISMATCH;
337 		return (0);
338 	}
339 	if (c->inf == (1|V_ASN1_CONSTRUCTED))
340 		c->slen= *length+ *(c->pp) - c->p;
341 	c->eos = 0;
342 	return (1);
343 }
344 
345 int
346 ASN1_STRING_copy(ASN1_STRING *dst, const ASN1_STRING *str)
347 {
348 	if (str == NULL)
349 		return 0;
350 	dst->type = str->type;
351 	if (!ASN1_STRING_set(dst, str->data, str->length))
352 		return 0;
353 	dst->flags = str->flags;
354 	return 1;
355 }
356 
357 ASN1_STRING *
358 ASN1_STRING_dup(const ASN1_STRING *str)
359 {
360 	ASN1_STRING *ret;
361 
362 	if (!str)
363 		return NULL;
364 	ret = ASN1_STRING_new();
365 	if (!ret)
366 		return NULL;
367 	if (!ASN1_STRING_copy(ret, str)) {
368 		ASN1_STRING_free(ret);
369 		return NULL;
370 	}
371 	return ret;
372 }
373 
374 int
375 ASN1_STRING_set(ASN1_STRING *str, const void *_data, int len)
376 {
377 	const char *data = _data;
378 
379 	if (len < 0) {
380 		if (data == NULL)
381 			return (0);
382 		else
383 			len = strlen(data);
384 	}
385 	if ((str->length < len) || (str->data == NULL)) {
386 		unsigned char *tmp;
387 		tmp = realloc(str->data, len + 1);
388 		if (tmp == NULL) {
389 			ASN1err(ASN1_F_ASN1_STRING_SET, ERR_R_MALLOC_FAILURE);
390 			return (0);
391 		}
392 		str->data = tmp;
393 	}
394 	str->length = len;
395 	if (data != NULL) {
396 		memmove(str->data, data, len);
397 	}
398 	str->data[str->length]='\0';
399 	return (1);
400 }
401 
402 void
403 ASN1_STRING_set0(ASN1_STRING *str, void *data, int len)
404 {
405 	free(str->data);
406 	str->data = data;
407 	str->length = len;
408 }
409 
410 ASN1_STRING *
411 ASN1_STRING_new(void)
412 {
413 	return (ASN1_STRING_type_new(V_ASN1_OCTET_STRING));
414 }
415 
416 ASN1_STRING *
417 ASN1_STRING_type_new(int type)
418 {
419 	ASN1_STRING *ret;
420 
421 	ret = malloc(sizeof(ASN1_STRING));
422 	if (ret == NULL) {
423 		ASN1err(ASN1_F_ASN1_STRING_TYPE_NEW, ERR_R_MALLOC_FAILURE);
424 		return (NULL);
425 	}
426 	ret->length = 0;
427 	ret->type = type;
428 	ret->data = NULL;
429 	ret->flags = 0;
430 	return (ret);
431 }
432 
433 void
434 ASN1_STRING_free(ASN1_STRING *a)
435 {
436 	if (a == NULL)
437 		return;
438 	if (a->data && !(a->flags & ASN1_STRING_FLAG_NDEF))
439 		free(a->data);
440 	free(a);
441 }
442 
443 int
444 ASN1_STRING_cmp(const ASN1_STRING *a, const ASN1_STRING *b)
445 {
446 	int i;
447 
448 	i = (a->length - b->length);
449 	if (i == 0) {
450 		i = memcmp(a->data, b->data, a->length);
451 		if (i == 0)
452 			return (a->type - b->type);
453 		else
454 			return (i);
455 	} else
456 		return (i);
457 }
458 
459 void
460 asn1_add_error(const unsigned char *address, int offset)
461 {
462 	ERR_asprintf_error_data("address=%p offset=%d", address, offset);
463 }
464 
465 int
466 ASN1_STRING_length(const ASN1_STRING *x)
467 {
468 	return M_ASN1_STRING_length(x);
469 }
470 
471 void
472 ASN1_STRING_length_set(ASN1_STRING *x, int len)
473 {
474 	M_ASN1_STRING_length_set(x, len);
475 	return;
476 }
477 
478 int
479 ASN1_STRING_type(ASN1_STRING *x)
480 {
481 	return M_ASN1_STRING_type(x);
482 }
483 
484 unsigned char *
485 ASN1_STRING_data(ASN1_STRING *x)
486 {
487 	return M_ASN1_STRING_data(x);
488 }
489