1 /*
2 * Copyright 1999-2025 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 /* X509 v3 extension utilities */
11
12 #include <stdio.h>
13 #include "internal/cryptlib.h"
14 #include <openssl/conf.h>
15 #include <openssl/x509v3.h>
16
17 #include "ext_dat.h"
18
19 static STACK_OF(X509V3_EXT_METHOD) *ext_list = NULL;
20
21 static int ext_cmp(const X509V3_EXT_METHOD *const *a,
22 const X509V3_EXT_METHOD *const *b);
23 static void ext_list_free(X509V3_EXT_METHOD *ext);
24
X509V3_EXT_add(X509V3_EXT_METHOD * ext)25 int X509V3_EXT_add(X509V3_EXT_METHOD *ext)
26 {
27 if (ext_list == NULL
28 && (ext_list = sk_X509V3_EXT_METHOD_new(ext_cmp)) == NULL) {
29 ERR_raise(ERR_LIB_X509V3, ERR_R_CRYPTO_LIB);
30 return 0;
31 }
32 if (!sk_X509V3_EXT_METHOD_push(ext_list, ext)) {
33 ERR_raise(ERR_LIB_X509V3, ERR_R_CRYPTO_LIB);
34 return 0;
35 }
36 return 1;
37 }
38
ext_cmp(const X509V3_EXT_METHOD * const * a,const X509V3_EXT_METHOD * const * b)39 static int ext_cmp(const X509V3_EXT_METHOD *const *a,
40 const X509V3_EXT_METHOD *const *b)
41 {
42 return ((*a)->ext_nid - (*b)->ext_nid);
43 }
44
45 DECLARE_OBJ_BSEARCH_CMP_FN(const X509V3_EXT_METHOD *,
46 const X509V3_EXT_METHOD *, ext);
47 IMPLEMENT_OBJ_BSEARCH_CMP_FN(const X509V3_EXT_METHOD *,
48 const X509V3_EXT_METHOD *, ext);
49
50 #include "standard_exts.h"
51
X509V3_EXT_get_nid(int nid)52 const X509V3_EXT_METHOD *X509V3_EXT_get_nid(int nid)
53 {
54 X509V3_EXT_METHOD tmp;
55 const X509V3_EXT_METHOD *t = &tmp, *const *ret;
56 int idx;
57
58 if (nid < 0)
59 return NULL;
60 tmp.ext_nid = nid;
61 ret = OBJ_bsearch_ext(&t, standard_exts, STANDARD_EXTENSION_COUNT);
62 if (ret)
63 return *ret;
64 if (!ext_list)
65 return NULL;
66 /* Ideally, this would be done under a lock */
67 sk_X509V3_EXT_METHOD_sort(ext_list);
68 idx = sk_X509V3_EXT_METHOD_find(ext_list, &tmp);
69 /* A failure to locate the item is handled by the value method */
70 return sk_X509V3_EXT_METHOD_value(ext_list, idx);
71 }
72
X509V3_EXT_get(X509_EXTENSION * ext)73 const X509V3_EXT_METHOD *X509V3_EXT_get(X509_EXTENSION *ext)
74 {
75 int nid;
76 if ((nid = OBJ_obj2nid(X509_EXTENSION_get_object(ext))) == NID_undef)
77 return NULL;
78 return X509V3_EXT_get_nid(nid);
79 }
80
X509V3_EXT_add_list(X509V3_EXT_METHOD * extlist)81 int X509V3_EXT_add_list(X509V3_EXT_METHOD *extlist)
82 {
83 for (; extlist->ext_nid != -1; extlist++)
84 if (!X509V3_EXT_add(extlist))
85 return 0;
86 return 1;
87 }
88
X509V3_EXT_add_alias(int nid_to,int nid_from)89 int X509V3_EXT_add_alias(int nid_to, int nid_from)
90 {
91 const X509V3_EXT_METHOD *ext;
92 X509V3_EXT_METHOD *tmpext;
93
94 if ((ext = X509V3_EXT_get_nid(nid_from)) == NULL) {
95 ERR_raise(ERR_LIB_X509V3, X509V3_R_EXTENSION_NOT_FOUND);
96 return 0;
97 }
98 if ((tmpext = OPENSSL_malloc(sizeof(*tmpext))) == NULL)
99 return 0;
100 *tmpext = *ext;
101 tmpext->ext_nid = nid_to;
102 tmpext->ext_flags |= X509V3_EXT_DYNAMIC;
103 if (!X509V3_EXT_add(tmpext)) {
104 OPENSSL_free(tmpext);
105 return 0;
106 }
107 return 1;
108 }
109
X509V3_EXT_cleanup(void)110 void X509V3_EXT_cleanup(void)
111 {
112 sk_X509V3_EXT_METHOD_pop_free(ext_list, ext_list_free);
113 ext_list = NULL;
114 }
115
ext_list_free(X509V3_EXT_METHOD * ext)116 static void ext_list_free(X509V3_EXT_METHOD *ext)
117 {
118 if (ext->ext_flags & X509V3_EXT_DYNAMIC)
119 OPENSSL_free(ext);
120 }
121
122 /*
123 * Legacy function: we don't need to add standard extensions any more because
124 * they are now kept in ext_dat.h.
125 */
126
X509V3_add_standard_extensions(void)127 int X509V3_add_standard_extensions(void)
128 {
129 return 1;
130 }
131
132 /* Return an extension internal structure */
133
X509V3_EXT_d2i(X509_EXTENSION * ext)134 void *X509V3_EXT_d2i(X509_EXTENSION *ext)
135 {
136 const X509V3_EXT_METHOD *method;
137 const unsigned char *p;
138 ASN1_STRING *extvalue;
139 int extlen;
140
141 if ((method = X509V3_EXT_get(ext)) == NULL)
142 return NULL;
143 extvalue = X509_EXTENSION_get_data(ext);
144 p = ASN1_STRING_get0_data(extvalue);
145 extlen = ASN1_STRING_length(extvalue);
146 if (method->it)
147 return ASN1_item_d2i(NULL, &p, extlen, ASN1_ITEM_ptr(method->it));
148 return method->d2i(NULL, &p, extlen);
149 }
150
151 /*-
152 * Get critical flag and decoded version of extension from a NID.
153 * The "idx" variable returns the last found extension and can
154 * be used to retrieve multiple extensions of the same NID.
155 * However multiple extensions with the same NID is usually
156 * due to a badly encoded certificate so if idx is NULL we
157 * choke if multiple extensions exist.
158 * The "crit" variable is set to the critical value.
159 * The return value is the decoded extension or NULL on
160 * error. The actual error can have several different causes,
161 * the value of *crit reflects the cause:
162 * >= 0, extension found but not decoded (reflects critical value).
163 * -1 extension not found.
164 * -2 extension occurs more than once.
165 */
166
X509V3_get_d2i(const STACK_OF (X509_EXTENSION)* x,int nid,int * crit,int * idx)167 void *X509V3_get_d2i(const STACK_OF(X509_EXTENSION) *x, int nid, int *crit,
168 int *idx)
169 {
170 int lastpos, i;
171 X509_EXTENSION *ex, *found_ex = NULL;
172
173 if (!x) {
174 if (idx)
175 *idx = -1;
176 if (crit)
177 *crit = -1;
178 return NULL;
179 }
180 if (idx)
181 lastpos = *idx + 1;
182 else
183 lastpos = 0;
184 if (lastpos < 0)
185 lastpos = 0;
186 for (i = lastpos; i < sk_X509_EXTENSION_num(x); i++) {
187 ex = sk_X509_EXTENSION_value(x, i);
188 if (OBJ_obj2nid(X509_EXTENSION_get_object(ex)) == nid) {
189 if (idx) {
190 *idx = i;
191 found_ex = ex;
192 break;
193 } else if (found_ex) {
194 /* Found more than one */
195 if (crit)
196 *crit = -2;
197 return NULL;
198 }
199 found_ex = ex;
200 }
201 }
202 if (found_ex) {
203 /* Found it */
204 if (crit)
205 *crit = X509_EXTENSION_get_critical(found_ex);
206 return X509V3_EXT_d2i(found_ex);
207 }
208
209 /* Extension not found */
210 if (idx)
211 *idx = -1;
212 if (crit)
213 *crit = -1;
214 return NULL;
215 }
216
217 /*
218 * This function is a general extension append, replace and delete utility.
219 * The precise operation is governed by the 'flags' value. The 'crit' and
220 * 'value' arguments (if relevant) are the extensions internal structure.
221 */
222
X509V3_add1_i2d(STACK_OF (X509_EXTENSION)** x,int nid,void * value,int crit,unsigned long flags)223 int X509V3_add1_i2d(STACK_OF(X509_EXTENSION) **x, int nid, void *value,
224 int crit, unsigned long flags)
225 {
226 int errcode, extidx = -1;
227 X509_EXTENSION *ext = NULL, *extmp;
228 STACK_OF(X509_EXTENSION) *ret = NULL;
229 unsigned long ext_op = flags & X509V3_ADD_OP_MASK;
230
231 /*
232 * If appending we don't care if it exists, otherwise look for existing
233 * extension.
234 */
235 if (ext_op != X509V3_ADD_APPEND)
236 extidx = X509v3_get_ext_by_NID(*x, nid, -1);
237
238 /* See if extension exists */
239 if (extidx >= 0) {
240 /* If keep existing, nothing to do */
241 if (ext_op == X509V3_ADD_KEEP_EXISTING)
242 return 1;
243 /* If default then its an error */
244 if (ext_op == X509V3_ADD_DEFAULT) {
245 errcode = X509V3_R_EXTENSION_EXISTS;
246 goto err;
247 }
248 /* If delete, just delete it */
249 if (ext_op == X509V3_ADD_DELETE) {
250 extmp = sk_X509_EXTENSION_delete(*x, extidx);
251 if (extmp == NULL)
252 return -1;
253 X509_EXTENSION_free(extmp);
254 return 1;
255 }
256 } else {
257 /*
258 * If replace existing or delete, error since extension must exist
259 */
260 if ((ext_op == X509V3_ADD_REPLACE_EXISTING) ||
261 (ext_op == X509V3_ADD_DELETE)) {
262 errcode = X509V3_R_EXTENSION_NOT_FOUND;
263 goto err;
264 }
265 }
266
267 /*
268 * If we get this far then we have to create an extension: could have
269 * some flags for alternative encoding schemes...
270 */
271
272 ext = X509V3_EXT_i2d(nid, crit, value);
273
274 if (!ext) {
275 ERR_raise(ERR_LIB_X509V3, X509V3_R_ERROR_CREATING_EXTENSION);
276 return 0;
277 }
278
279 /* If extension exists replace it.. */
280 if (extidx >= 0) {
281 extmp = sk_X509_EXTENSION_value(*x, extidx);
282 X509_EXTENSION_free(extmp);
283 if (!sk_X509_EXTENSION_set(*x, extidx, ext))
284 return -1;
285 return 1;
286 }
287
288 ret = *x;
289 if (*x == NULL
290 && (ret = sk_X509_EXTENSION_new_null()) == NULL)
291 goto m_fail;
292 if (!sk_X509_EXTENSION_push(ret, ext))
293 goto m_fail;
294
295 *x = ret;
296 return 1;
297
298 m_fail:
299 /* ERR_raise(ERR_LIB_X509V3, ERR_R_CRYPTO_LIB); */
300 if (ret != *x)
301 sk_X509_EXTENSION_free(ret);
302 X509_EXTENSION_free(ext);
303 return -1;
304
305 err:
306 if (!(flags & X509V3_ADD_SILENT))
307 ERR_raise(ERR_LIB_X509V3, errcode);
308 return 0;
309 }
310