1 /*
2 * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 #include <stdio.h>
11 #include <limits.h>
12 #include "internal/cryptlib.h"
13 #include <openssl/asn1.h>
14 #include "asn1_local.h"
15
16 static int asn1_get_length(const unsigned char **pp, int *inf, long *rl,
17 long max);
18 static void asn1_put_length(unsigned char **pp, int length);
19
_asn1_check_infinite_end(const unsigned char ** p,long len)20 static int _asn1_check_infinite_end(const unsigned char **p, long len)
21 {
22 /*
23 * If there is 0 or 1 byte left, the length check should pick things up
24 */
25 if (len <= 0) {
26 return 1;
27 } else {
28 if ((len >= 2) && ((*p)[0] == 0) && ((*p)[1] == 0)) {
29 (*p) += 2;
30 return 1;
31 }
32 }
33 return 0;
34 }
35
ASN1_check_infinite_end(unsigned char ** p,long len)36 int ASN1_check_infinite_end(unsigned char **p, long len)
37 {
38 return _asn1_check_infinite_end((const unsigned char **)p, len);
39 }
40
ASN1_const_check_infinite_end(const unsigned char ** p,long len)41 int ASN1_const_check_infinite_end(const unsigned char **p, long len)
42 {
43 return _asn1_check_infinite_end(p, len);
44 }
45
ASN1_get_object(const unsigned char ** pp,long * plength,int * ptag,int * pclass,long omax)46 int ASN1_get_object(const unsigned char **pp, long *plength, int *ptag,
47 int *pclass, long omax)
48 {
49 int i, ret;
50 long len;
51 const unsigned char *p = *pp;
52 int tag, xclass, inf;
53 long max = omax;
54
55 if (omax <= 0) {
56 ERR_raise(ERR_LIB_ASN1, ASN1_R_TOO_SMALL);
57 return 0x80;
58 }
59 ret = (*p & V_ASN1_CONSTRUCTED);
60 xclass = (*p & V_ASN1_PRIVATE);
61 i = *p & V_ASN1_PRIMITIVE_TAG;
62 if (i == V_ASN1_PRIMITIVE_TAG) { /* high-tag */
63 p++;
64 if (--max == 0)
65 goto err;
66 len = 0;
67 while (*p & 0x80) {
68 len <<= 7L;
69 len |= *(p++) & 0x7f;
70 if (--max == 0)
71 goto err;
72 if (len > (INT_MAX >> 7L))
73 goto err;
74 }
75 len <<= 7L;
76 len |= *(p++) & 0x7f;
77 tag = (int)len;
78 if (--max == 0)
79 goto err;
80 } else {
81 tag = i;
82 p++;
83 if (--max == 0)
84 goto err;
85 }
86 *ptag = tag;
87 *pclass = xclass;
88 if (!asn1_get_length(&p, &inf, plength, max))
89 goto err;
90
91 if (inf && !(ret & V_ASN1_CONSTRUCTED))
92 goto err;
93
94 if (*plength > (omax - (p - *pp))) {
95 ERR_raise(ERR_LIB_ASN1, ASN1_R_TOO_LONG);
96 /*
97 * Set this so that even if things are not long enough the values are
98 * set correctly
99 */
100 ret |= 0x80;
101 }
102 *pp = p;
103 return ret | inf;
104 err:
105 ERR_raise(ERR_LIB_ASN1, ASN1_R_HEADER_TOO_LONG);
106 return 0x80;
107 }
108
109 /*
110 * Decode a length field.
111 * The short form is a single byte defining a length 0 - 127.
112 * The long form is a byte 0 - 127 with the top bit set and this indicates
113 * the number of following octets that contain the length. These octets
114 * are stored most significant digit first.
115 */
asn1_get_length(const unsigned char ** pp,int * inf,long * rl,long max)116 static int asn1_get_length(const unsigned char **pp, int *inf, long *rl,
117 long max)
118 {
119 const unsigned char *p = *pp;
120 unsigned long ret = 0;
121 int i;
122
123 if (max-- < 1)
124 return 0;
125 if (*p == 0x80) {
126 *inf = 1;
127 p++;
128 } else {
129 *inf = 0;
130 i = *p & 0x7f;
131 if (*p++ & 0x80) {
132 if (max < i + 1)
133 return 0;
134 /* Skip leading zeroes */
135 while (i > 0 && *p == 0) {
136 p++;
137 i--;
138 }
139 if (i > (int)sizeof(long))
140 return 0;
141 while (i > 0) {
142 ret <<= 8;
143 ret |= *p++;
144 i--;
145 }
146 if (ret > LONG_MAX)
147 return 0;
148 } else {
149 ret = i;
150 }
151 }
152 *pp = p;
153 *rl = (long)ret;
154 return 1;
155 }
156
157 /*
158 * constructed == 2 for indefinite length constructed
159 */
ASN1_put_object(unsigned char ** pp,int constructed,int length,int tag,int xclass)160 void ASN1_put_object(unsigned char **pp, int constructed, int length, int tag,
161 int xclass)
162 {
163 unsigned char *p = *pp;
164 int i, ttag;
165
166 i = (constructed) ? V_ASN1_CONSTRUCTED : 0;
167 i |= (xclass & V_ASN1_PRIVATE);
168 if (tag < 31) {
169 *(p++) = i | (tag & V_ASN1_PRIMITIVE_TAG);
170 } else {
171 *(p++) = i | V_ASN1_PRIMITIVE_TAG;
172 for (i = 0, ttag = tag; ttag > 0; i++)
173 ttag >>= 7;
174 ttag = i;
175 while (i-- > 0) {
176 p[i] = tag & 0x7f;
177 if (i != (ttag - 1))
178 p[i] |= 0x80;
179 tag >>= 7;
180 }
181 p += ttag;
182 }
183 if (constructed == 2)
184 *(p++) = 0x80;
185 else
186 asn1_put_length(&p, length);
187 *pp = p;
188 }
189
ASN1_put_eoc(unsigned char ** pp)190 int ASN1_put_eoc(unsigned char **pp)
191 {
192 unsigned char *p = *pp;
193
194 *p++ = 0;
195 *p++ = 0;
196 *pp = p;
197 return 2;
198 }
199
asn1_put_length(unsigned char ** pp,int length)200 static void asn1_put_length(unsigned char **pp, int length)
201 {
202 unsigned char *p = *pp;
203 int i, len;
204
205 if (length <= 127) {
206 *(p++) = (unsigned char)length;
207 } else {
208 len = length;
209 for (i = 0; len > 0; i++)
210 len >>= 8;
211 *(p++) = i | 0x80;
212 len = i;
213 while (i-- > 0) {
214 p[i] = length & 0xff;
215 length >>= 8;
216 }
217 p += len;
218 }
219 *pp = p;
220 }
221
ASN1_object_size(int constructed,int length,int tag)222 int ASN1_object_size(int constructed, int length, int tag)
223 {
224 int ret = 1;
225
226 if (length < 0)
227 return -1;
228 if (tag >= 31) {
229 while (tag > 0) {
230 tag >>= 7;
231 ret++;
232 }
233 }
234 if (constructed == 2) {
235 ret += 3;
236 } else {
237 ret++;
238 if (length > 127) {
239 int tmplen = length;
240 while (tmplen > 0) {
241 tmplen >>= 8;
242 ret++;
243 }
244 }
245 }
246 if (ret >= INT_MAX - length)
247 return -1;
248 return ret + length;
249 }
250
ASN1_STRING_copy(ASN1_STRING * dst,const ASN1_STRING * str)251 int ASN1_STRING_copy(ASN1_STRING *dst, const ASN1_STRING *str)
252 {
253 if (str == NULL)
254 return 0;
255 dst->type = str->type;
256 if (!ASN1_STRING_set(dst, str->data, str->length))
257 return 0;
258 /* Copy flags but preserve embed value */
259 dst->flags &= ASN1_STRING_FLAG_EMBED;
260 dst->flags |= str->flags & ~ASN1_STRING_FLAG_EMBED;
261 return 1;
262 }
263
ASN1_STRING_dup(const ASN1_STRING * str)264 ASN1_STRING *ASN1_STRING_dup(const ASN1_STRING *str)
265 {
266 ASN1_STRING *ret;
267
268 if (!str)
269 return NULL;
270 ret = ASN1_STRING_new();
271 if (ret == NULL)
272 return NULL;
273 if (!ASN1_STRING_copy(ret, str)) {
274 ASN1_STRING_free(ret);
275 return NULL;
276 }
277 return ret;
278 }
279
ASN1_STRING_set(ASN1_STRING * str,const void * _data,int len_in)280 int ASN1_STRING_set(ASN1_STRING *str, const void *_data, int len_in)
281 {
282 unsigned char *c;
283 const char *data = _data;
284 size_t len;
285
286 if (len_in < 0) {
287 if (data == NULL)
288 return 0;
289 len = strlen(data);
290 } else {
291 len = (size_t)len_in;
292 }
293 /*
294 * Verify that the length fits within an integer for assignment to
295 * str->length below. The additional 1 is subtracted to allow for the
296 * '\0' terminator even though this isn't strictly necessary.
297 */
298 if (len > INT_MAX - 1) {
299 ERR_raise(ERR_LIB_ASN1, ASN1_R_TOO_LARGE);
300 return 0;
301 }
302 if ((size_t)str->length <= len || str->data == NULL) {
303 c = str->data;
304 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
305 /* No NUL terminator in fuzzing builds */
306 str->data = OPENSSL_realloc(c, len != 0 ? len : 1);
307 #else
308 str->data = OPENSSL_realloc(c, len + 1);
309 #endif
310 if (str->data == NULL) {
311 ERR_raise(ERR_LIB_ASN1, ERR_R_MALLOC_FAILURE);
312 str->data = c;
313 return 0;
314 }
315 }
316 str->length = len;
317 if (data != NULL) {
318 memcpy(str->data, data, len);
319 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
320 /* Set the unused byte to something non NUL and printable. */
321 if (len == 0)
322 str->data[len] = '~';
323 #else
324 /*
325 * Add a NUL terminator. This should not be necessary - but we add it as
326 * a safety precaution
327 */
328 str->data[len] = '\0';
329 #endif
330 }
331 return 1;
332 }
333
ASN1_STRING_set0(ASN1_STRING * str,void * data,int len)334 void ASN1_STRING_set0(ASN1_STRING *str, void *data, int len)
335 {
336 OPENSSL_free(str->data);
337 str->data = data;
338 str->length = len;
339 }
340
ASN1_STRING_new(void)341 ASN1_STRING *ASN1_STRING_new(void)
342 {
343 return ASN1_STRING_type_new(V_ASN1_OCTET_STRING);
344 }
345
ASN1_STRING_type_new(int type)346 ASN1_STRING *ASN1_STRING_type_new(int type)
347 {
348 ASN1_STRING *ret;
349
350 ret = OPENSSL_zalloc(sizeof(*ret));
351 if (ret == NULL) {
352 ERR_raise(ERR_LIB_ASN1, ERR_R_MALLOC_FAILURE);
353 return NULL;
354 }
355 ret->type = type;
356 return ret;
357 }
358
ossl_asn1_string_embed_free(ASN1_STRING * a,int embed)359 void ossl_asn1_string_embed_free(ASN1_STRING *a, int embed)
360 {
361 if (a == NULL)
362 return;
363 if (!(a->flags & ASN1_STRING_FLAG_NDEF))
364 OPENSSL_free(a->data);
365 if (embed == 0)
366 OPENSSL_free(a);
367 }
368
ASN1_STRING_free(ASN1_STRING * a)369 void ASN1_STRING_free(ASN1_STRING *a)
370 {
371 if (a == NULL)
372 return;
373 ossl_asn1_string_embed_free(a, a->flags & ASN1_STRING_FLAG_EMBED);
374 }
375
ASN1_STRING_clear_free(ASN1_STRING * a)376 void ASN1_STRING_clear_free(ASN1_STRING *a)
377 {
378 if (a == NULL)
379 return;
380 if (a->data && !(a->flags & ASN1_STRING_FLAG_NDEF))
381 OPENSSL_cleanse(a->data, a->length);
382 ASN1_STRING_free(a);
383 }
384
ASN1_STRING_cmp(const ASN1_STRING * a,const ASN1_STRING * b)385 int ASN1_STRING_cmp(const ASN1_STRING *a, const ASN1_STRING *b)
386 {
387 int i;
388
389 i = (a->length - b->length);
390 if (i == 0) {
391 if (a->length != 0)
392 i = memcmp(a->data, b->data, a->length);
393 if (i == 0)
394 return a->type - b->type;
395 else
396 return i;
397 } else {
398 return i;
399 }
400 }
401
ASN1_STRING_length(const ASN1_STRING * x)402 int ASN1_STRING_length(const ASN1_STRING *x)
403 {
404 return x->length;
405 }
406
407 #ifndef OPENSSL_NO_DEPRECATED_3_0
ASN1_STRING_length_set(ASN1_STRING * x,int len)408 void ASN1_STRING_length_set(ASN1_STRING *x, int len)
409 {
410 x->length = len;
411 }
412 #endif
413
ASN1_STRING_type(const ASN1_STRING * x)414 int ASN1_STRING_type(const ASN1_STRING *x)
415 {
416 return x->type;
417 }
418
ASN1_STRING_get0_data(const ASN1_STRING * x)419 const unsigned char *ASN1_STRING_get0_data(const ASN1_STRING *x)
420 {
421 return x->data;
422 }
423
424 #ifndef OPENSSL_NO_DEPRECATED_1_1_0
ASN1_STRING_data(ASN1_STRING * x)425 unsigned char *ASN1_STRING_data(ASN1_STRING *x)
426 {
427 return x->data;
428 }
429 #endif
430
431 /* |max_len| excludes NUL terminator and may be 0 to indicate no restriction */
ossl_sk_ASN1_UTF8STRING2text(STACK_OF (ASN1_UTF8STRING)* text,const char * sep,size_t max_len)432 char *ossl_sk_ASN1_UTF8STRING2text(STACK_OF(ASN1_UTF8STRING) *text,
433 const char *sep, size_t max_len)
434 {
435 int i;
436 ASN1_UTF8STRING *current;
437 size_t length = 0, sep_len;
438 char *result = NULL;
439 char *p;
440
441 if (sep == NULL)
442 sep = "";
443 sep_len = strlen(sep);
444
445 for (i = 0; i < sk_ASN1_UTF8STRING_num(text); i++) {
446 current = sk_ASN1_UTF8STRING_value(text, i);
447 if (i > 0)
448 length += sep_len;
449 length += ASN1_STRING_length(current);
450 if (max_len != 0 && length > max_len)
451 return NULL;
452 }
453 if ((result = OPENSSL_malloc(length + 1)) == NULL)
454 return NULL;
455
456 p = result;
457 for (i = 0; i < sk_ASN1_UTF8STRING_num(text); i++) {
458 current = sk_ASN1_UTF8STRING_value(text, i);
459 length = ASN1_STRING_length(current);
460 if (i > 0 && sep_len > 0) {
461 strncpy(p, sep, sep_len + 1); /* using + 1 to silence gcc warning */
462 p += sep_len;
463 }
464 strncpy(p, (const char *)ASN1_STRING_get0_data(current), length);
465 p += length;
466 }
467 *p = '\0';
468
469 return result;
470 }
471