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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 <limits.h>
60 #include <string.h>
61 
62 #include <openssl/bytestring.h>
63 #include <openssl/err.h>
64 #include <openssl/mem.h>
65 
66 #include "../internal.h"
67 #include "internal.h"
68 
69 
70 // Cross-module errors from crypto/x509/i2d_pr.c.
71 OPENSSL_DECLARE_ERROR_REASON(ASN1, UNSUPPORTED_PUBLIC_KEY_TYPE)
72 
73 // Cross-module errors from crypto/x509/algorithm.c.
74 OPENSSL_DECLARE_ERROR_REASON(ASN1, CONTEXT_NOT_INITIALISED)
75 OPENSSL_DECLARE_ERROR_REASON(ASN1, DIGEST_AND_KEY_TYPE_NOT_SUPPORTED)
76 OPENSSL_DECLARE_ERROR_REASON(ASN1, UNKNOWN_MESSAGE_DIGEST_ALGORITHM)
77 OPENSSL_DECLARE_ERROR_REASON(ASN1, UNKNOWN_SIGNATURE_ALGORITHM)
78 OPENSSL_DECLARE_ERROR_REASON(ASN1, WRONG_PUBLIC_KEY_TYPE)
79 // Cross-module errors from crypto/x509/asn1_gen.c. TODO(davidben): Remove
80 // these once asn1_gen.c is gone.
81 OPENSSL_DECLARE_ERROR_REASON(ASN1, DEPTH_EXCEEDED)
82 OPENSSL_DECLARE_ERROR_REASON(ASN1, ILLEGAL_BITSTRING_FORMAT)
83 OPENSSL_DECLARE_ERROR_REASON(ASN1, ILLEGAL_BOOLEAN)
84 OPENSSL_DECLARE_ERROR_REASON(ASN1, ILLEGAL_FORMAT)
85 OPENSSL_DECLARE_ERROR_REASON(ASN1, ILLEGAL_HEX)
86 OPENSSL_DECLARE_ERROR_REASON(ASN1, ILLEGAL_IMPLICIT_TAG)
87 OPENSSL_DECLARE_ERROR_REASON(ASN1, ILLEGAL_INTEGER)
88 OPENSSL_DECLARE_ERROR_REASON(ASN1, ILLEGAL_NESTED_TAGGING)
89 OPENSSL_DECLARE_ERROR_REASON(ASN1, ILLEGAL_NULL_VALUE)
90 OPENSSL_DECLARE_ERROR_REASON(ASN1, ILLEGAL_OBJECT)
91 OPENSSL_DECLARE_ERROR_REASON(ASN1, ILLEGAL_TIME_VALUE)
92 OPENSSL_DECLARE_ERROR_REASON(ASN1, INTEGER_NOT_ASCII_FORMAT)
93 OPENSSL_DECLARE_ERROR_REASON(ASN1, INVALID_MODIFIER)
94 OPENSSL_DECLARE_ERROR_REASON(ASN1, INVALID_NUMBER)
95 OPENSSL_DECLARE_ERROR_REASON(ASN1, LIST_ERROR)
96 OPENSSL_DECLARE_ERROR_REASON(ASN1, MISSING_VALUE)
97 OPENSSL_DECLARE_ERROR_REASON(ASN1, NOT_ASCII_FORMAT)
98 OPENSSL_DECLARE_ERROR_REASON(ASN1, OBJECT_NOT_ASCII_FORMAT)
99 OPENSSL_DECLARE_ERROR_REASON(ASN1, SEQUENCE_OR_SET_NEEDS_CONFIG)
100 OPENSSL_DECLARE_ERROR_REASON(ASN1, TIME_NOT_ASCII_FORMAT)
101 OPENSSL_DECLARE_ERROR_REASON(ASN1, UNKNOWN_FORMAT)
102 OPENSSL_DECLARE_ERROR_REASON(ASN1, UNKNOWN_TAG)
103 OPENSSL_DECLARE_ERROR_REASON(ASN1, UNSUPPORTED_TYPE)
104 
105 static void asn1_put_length(unsigned char **pp, int length);
106 
ASN1_get_object(const unsigned char ** inp,long * out_len,int * out_tag,int * out_class,long in_len)107 int ASN1_get_object(const unsigned char **inp, long *out_len, int *out_tag,
108                     int *out_class, long in_len) {
109   if (in_len < 0) {
110     OPENSSL_PUT_ERROR(ASN1, ASN1_R_HEADER_TOO_LONG);
111     return 0x80;
112   }
113 
114   CBS_ASN1_TAG tag;
115   CBS cbs, body;
116   CBS_init(&cbs, *inp, (size_t)in_len);
117   if (!CBS_get_any_asn1(&cbs, &body, &tag) ||
118       // Bound the length to comfortably fit in an int. Lengths in this
119       // module often switch between int and long without overflow checks.
120       CBS_len(&body) > INT_MAX / 2) {
121     OPENSSL_PUT_ERROR(ASN1, ASN1_R_HEADER_TOO_LONG);
122     return 0x80;
123   }
124 
125   // Convert between tag representations.
126   int tag_class = (tag & CBS_ASN1_CLASS_MASK) >> CBS_ASN1_TAG_SHIFT;
127   int constructed = (tag & CBS_ASN1_CONSTRUCTED) >> CBS_ASN1_TAG_SHIFT;
128   int tag_number = tag & CBS_ASN1_TAG_NUMBER_MASK;
129 
130   // To avoid ambiguity with V_ASN1_NEG, impose a limit on universal tags.
131   if (tag_class == V_ASN1_UNIVERSAL && tag_number > V_ASN1_MAX_UNIVERSAL) {
132     OPENSSL_PUT_ERROR(ASN1, ASN1_R_HEADER_TOO_LONG);
133     return 0x80;
134   }
135 
136   *inp = CBS_data(&body);
137   *out_len = CBS_len(&body);
138   *out_tag = tag_number;
139   *out_class = tag_class;
140   return constructed;
141 }
142 
143 // class 0 is constructed constructed == 2 for indefinite length constructed
ASN1_put_object(unsigned char ** pp,int constructed,int length,int tag,int xclass)144 void ASN1_put_object(unsigned char **pp, int constructed, int length, int tag,
145                      int xclass) {
146   unsigned char *p = *pp;
147   int i, ttag;
148 
149   i = (constructed) ? V_ASN1_CONSTRUCTED : 0;
150   i |= (xclass & V_ASN1_PRIVATE);
151   if (tag < 31) {
152     *(p++) = i | (tag & V_ASN1_PRIMITIVE_TAG);
153   } else {
154     *(p++) = i | V_ASN1_PRIMITIVE_TAG;
155     for (i = 0, ttag = tag; ttag > 0; i++) {
156       ttag >>= 7;
157     }
158     ttag = i;
159     while (i-- > 0) {
160       p[i] = tag & 0x7f;
161       if (i != (ttag - 1)) {
162         p[i] |= 0x80;
163       }
164       tag >>= 7;
165     }
166     p += ttag;
167   }
168   if (constructed == 2) {
169     *(p++) = 0x80;
170   } else {
171     asn1_put_length(&p, length);
172   }
173   *pp = p;
174 }
175 
ASN1_put_eoc(unsigned char ** pp)176 int ASN1_put_eoc(unsigned char **pp) {
177   // This function is no longer used in the library, but some external code
178   // uses it.
179   unsigned char *p = *pp;
180   *p++ = 0;
181   *p++ = 0;
182   *pp = p;
183   return 2;
184 }
185 
asn1_put_length(unsigned char ** pp,int length)186 static void asn1_put_length(unsigned char **pp, int length) {
187   unsigned char *p = *pp;
188   int i, l;
189   if (length <= 127) {
190     *(p++) = (unsigned char)length;
191   } else {
192     l = length;
193     for (i = 0; l > 0; i++) {
194       l >>= 8;
195     }
196     *(p++) = i | 0x80;
197     l = i;
198     while (i-- > 0) {
199       p[i] = length & 0xff;
200       length >>= 8;
201     }
202     p += l;
203   }
204   *pp = p;
205 }
206 
ASN1_object_size(int constructed,int length,int tag)207 int ASN1_object_size(int constructed, int length, int tag) {
208   int ret = 1;
209   if (length < 0) {
210     return -1;
211   }
212   if (tag >= 31) {
213     while (tag > 0) {
214       tag >>= 7;
215       ret++;
216     }
217   }
218   if (constructed == 2) {
219     ret += 3;
220   } else {
221     ret++;
222     if (length > 127) {
223       int tmplen = length;
224       while (tmplen > 0) {
225         tmplen >>= 8;
226         ret++;
227       }
228     }
229   }
230   if (ret >= INT_MAX - length) {
231     return -1;
232   }
233   return ret + length;
234 }
235 
ASN1_STRING_copy(ASN1_STRING * dst,const ASN1_STRING * str)236 int ASN1_STRING_copy(ASN1_STRING *dst, const ASN1_STRING *str) {
237   if (str == NULL) {
238     return 0;
239   }
240   if (!ASN1_STRING_set(dst, str->data, str->length)) {
241     return 0;
242   }
243   dst->type = str->type;
244   dst->flags = str->flags;
245   return 1;
246 }
247 
ASN1_STRING_dup(const ASN1_STRING * str)248 ASN1_STRING *ASN1_STRING_dup(const ASN1_STRING *str) {
249   ASN1_STRING *ret;
250   if (!str) {
251     return NULL;
252   }
253   ret = ASN1_STRING_new();
254   if (!ret) {
255     return NULL;
256   }
257   if (!ASN1_STRING_copy(ret, str)) {
258     ASN1_STRING_free(ret);
259     return NULL;
260   }
261   return ret;
262 }
263 
ASN1_STRING_set(ASN1_STRING * str,const void * _data,ossl_ssize_t len_s)264 int ASN1_STRING_set(ASN1_STRING *str, const void *_data, ossl_ssize_t len_s) {
265   const char *data = _data;
266   size_t len;
267   if (len_s < 0) {
268     if (data == NULL) {
269       return 0;
270     }
271     len = strlen(data);
272   } else {
273     len = (size_t)len_s;
274   }
275 
276   // |ASN1_STRING| cannot represent strings that exceed |int|, and we must
277   // reserve space for a trailing NUL below.
278   if (len > INT_MAX || len + 1 < len) {
279     OPENSSL_PUT_ERROR(ASN1, ERR_R_OVERFLOW);
280     return 0;
281   }
282 
283   if (str->length <= (int)len || str->data == NULL) {
284     unsigned char *c = str->data;
285     if (c == NULL) {
286       str->data = OPENSSL_malloc(len + 1);
287     } else {
288       str->data = OPENSSL_realloc(c, len + 1);
289     }
290 
291     if (str->data == NULL) {
292       str->data = c;
293       return 0;
294     }
295   }
296   str->length = (int)len;
297   if (data != NULL) {
298     OPENSSL_memcpy(str->data, data, len);
299     // Historically, OpenSSL would NUL-terminate most (but not all)
300     // |ASN1_STRING|s, in case anyone accidentally passed |str->data| into a
301     // function expecting a C string. We retain this behavior for compatibility,
302     // but code must not rely on this. See CVE-2021-3712.
303     str->data[len] = '\0';
304   }
305   return 1;
306 }
307 
ASN1_STRING_set0(ASN1_STRING * str,void * data,int len)308 void ASN1_STRING_set0(ASN1_STRING *str, void *data, int len) {
309   OPENSSL_free(str->data);
310   str->data = data;
311   str->length = len;
312 }
313 
ASN1_STRING_new(void)314 ASN1_STRING *ASN1_STRING_new(void) {
315   return (ASN1_STRING_type_new(V_ASN1_OCTET_STRING));
316 }
317 
ASN1_STRING_type_new(int type)318 ASN1_STRING *ASN1_STRING_type_new(int type) {
319   ASN1_STRING *ret;
320 
321   ret = (ASN1_STRING *)OPENSSL_malloc(sizeof(ASN1_STRING));
322   if (ret == NULL) {
323     return NULL;
324   }
325   ret->length = 0;
326   ret->type = type;
327   ret->data = NULL;
328   ret->flags = 0;
329   return ret;
330 }
331 
ASN1_STRING_free(ASN1_STRING * str)332 void ASN1_STRING_free(ASN1_STRING *str) {
333   if (str == NULL) {
334     return;
335   }
336   OPENSSL_free(str->data);
337   OPENSSL_free(str);
338 }
339 
ASN1_STRING_cmp(const ASN1_STRING * a,const ASN1_STRING * b)340 int ASN1_STRING_cmp(const ASN1_STRING *a, const ASN1_STRING *b) {
341   // Capture padding bits and implicit truncation in BIT STRINGs.
342   int a_length = a->length, b_length = b->length;
343   uint8_t a_padding = 0, b_padding = 0;
344   if (a->type == V_ASN1_BIT_STRING) {
345     a_length = asn1_bit_string_length(a, &a_padding);
346   }
347   if (b->type == V_ASN1_BIT_STRING) {
348     b_length = asn1_bit_string_length(b, &b_padding);
349   }
350 
351   if (a_length < b_length) {
352     return -1;
353   }
354   if (a_length > b_length) {
355     return 1;
356   }
357   // In a BIT STRING, the number of bits is 8 * length - padding. Invert this
358   // comparison so we compare by lengths.
359   if (a_padding > b_padding) {
360     return -1;
361   }
362   if (a_padding < b_padding) {
363     return 1;
364   }
365 
366   int ret = OPENSSL_memcmp(a->data, b->data, a_length);
367   if (ret != 0) {
368     return ret;
369   }
370 
371   // Comparing the type first is more natural, but this matches OpenSSL.
372   if (a->type < b->type) {
373     return -1;
374   }
375   if (a->type > b->type) {
376     return 1;
377   }
378   return 0;
379 }
380 
ASN1_STRING_length(const ASN1_STRING * str)381 int ASN1_STRING_length(const ASN1_STRING *str) { return str->length; }
382 
ASN1_STRING_type(const ASN1_STRING * str)383 int ASN1_STRING_type(const ASN1_STRING *str) { return str->type; }
384 
ASN1_STRING_data(ASN1_STRING * str)385 unsigned char *ASN1_STRING_data(ASN1_STRING *str) { return str->data; }
386 
ASN1_STRING_get0_data(const ASN1_STRING * str)387 const unsigned char *ASN1_STRING_get0_data(const ASN1_STRING *str) {
388   return str->data;
389 }
390