1/*
2 * Copyright 1999-2022 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
19static STACK_OF(X509V3_EXT_METHOD) *ext_list = NULL;
20
21static int ext_cmp(const X509V3_EXT_METHOD *const *a,
22                   const X509V3_EXT_METHOD *const *b);
23static void ext_list_free(X509V3_EXT_METHOD *ext);
24
25int 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_MALLOC_FAILURE);
30        return 0;
31    }
32    if (!sk_X509V3_EXT_METHOD_push(ext_list, ext)) {
33        ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
34        return 0;
35    }
36    return 1;
37}
38
39static 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
45DECLARE_OBJ_BSEARCH_CMP_FN(const X509V3_EXT_METHOD *,
46                           const X509V3_EXT_METHOD *, ext);
47IMPLEMENT_OBJ_BSEARCH_CMP_FN(const X509V3_EXT_METHOD *,
48                             const X509V3_EXT_METHOD *, ext);
49
50#include "standard_exts.h"
51
52const 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    idx = sk_X509V3_EXT_METHOD_find(ext_list, &tmp);
67    return sk_X509V3_EXT_METHOD_value(ext_list, idx);
68}
69
70const X509V3_EXT_METHOD *X509V3_EXT_get(X509_EXTENSION *ext)
71{
72    int nid;
73    if ((nid = OBJ_obj2nid(X509_EXTENSION_get_object(ext))) == NID_undef)
74        return NULL;
75    return X509V3_EXT_get_nid(nid);
76}
77
78int X509V3_EXT_add_list(X509V3_EXT_METHOD *extlist)
79{
80    for (; extlist->ext_nid != -1; extlist++)
81        if (!X509V3_EXT_add(extlist))
82            return 0;
83    return 1;
84}
85
86int X509V3_EXT_add_alias(int nid_to, int nid_from)
87{
88    const X509V3_EXT_METHOD *ext;
89    X509V3_EXT_METHOD *tmpext;
90
91    if ((ext = X509V3_EXT_get_nid(nid_from)) == NULL) {
92        ERR_raise(ERR_LIB_X509V3, X509V3_R_EXTENSION_NOT_FOUND);
93        return 0;
94    }
95    if ((tmpext = OPENSSL_malloc(sizeof(*tmpext))) == NULL) {
96        ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
97        return 0;
98    }
99    *tmpext = *ext;
100    tmpext->ext_nid = nid_to;
101    tmpext->ext_flags |= X509V3_EXT_DYNAMIC;
102    return X509V3_EXT_add(tmpext);
103}
104
105void X509V3_EXT_cleanup(void)
106{
107    sk_X509V3_EXT_METHOD_pop_free(ext_list, ext_list_free);
108    ext_list = NULL;
109}
110
111static void ext_list_free(X509V3_EXT_METHOD *ext)
112{
113    if (ext->ext_flags & X509V3_EXT_DYNAMIC)
114        OPENSSL_free(ext);
115}
116
117/*
118 * Legacy function: we don't need to add standard extensions any more because
119 * they are now kept in ext_dat.h.
120 */
121
122int X509V3_add_standard_extensions(void)
123{
124    return 1;
125}
126
127/* Return an extension internal structure */
128
129void *X509V3_EXT_d2i(X509_EXTENSION *ext)
130{
131    const X509V3_EXT_METHOD *method;
132    const unsigned char *p;
133    ASN1_STRING *extvalue;
134    int extlen;
135
136    if ((method = X509V3_EXT_get(ext)) == NULL)
137        return NULL;
138    extvalue = X509_EXTENSION_get_data(ext);
139    p = ASN1_STRING_get0_data(extvalue);
140    extlen = ASN1_STRING_length(extvalue);
141    if (method->it)
142        return ASN1_item_d2i(NULL, &p, extlen, ASN1_ITEM_ptr(method->it));
143    return method->d2i(NULL, &p, extlen);
144}
145
146/*-
147 * Get critical flag and decoded version of extension from a NID.
148 * The "idx" variable returns the last found extension and can
149 * be used to retrieve multiple extensions of the same NID.
150 * However multiple extensions with the same NID is usually
151 * due to a badly encoded certificate so if idx is NULL we
152 * choke if multiple extensions exist.
153 * The "crit" variable is set to the critical value.
154 * The return value is the decoded extension or NULL on
155 * error. The actual error can have several different causes,
156 * the value of *crit reflects the cause:
157 * >= 0, extension found but not decoded (reflects critical value).
158 * -1 extension not found.
159 * -2 extension occurs more than once.
160 */
161
162void *X509V3_get_d2i(const STACK_OF(X509_EXTENSION) *x, int nid, int *crit,
163                     int *idx)
164{
165    int lastpos, i;
166    X509_EXTENSION *ex, *found_ex = NULL;
167
168    if (!x) {
169        if (idx)
170            *idx = -1;
171        if (crit)
172            *crit = -1;
173        return NULL;
174    }
175    if (idx)
176        lastpos = *idx + 1;
177    else
178        lastpos = 0;
179    if (lastpos < 0)
180        lastpos = 0;
181    for (i = lastpos; i < sk_X509_EXTENSION_num(x); i++) {
182        ex = sk_X509_EXTENSION_value(x, i);
183        if (OBJ_obj2nid(X509_EXTENSION_get_object(ex)) == nid) {
184            if (idx) {
185                *idx = i;
186                found_ex = ex;
187                break;
188            } else if (found_ex) {
189                /* Found more than one */
190                if (crit)
191                    *crit = -2;
192                return NULL;
193            }
194            found_ex = ex;
195        }
196    }
197    if (found_ex) {
198        /* Found it */
199        if (crit)
200            *crit = X509_EXTENSION_get_critical(found_ex);
201        return X509V3_EXT_d2i(found_ex);
202    }
203
204    /* Extension not found */
205    if (idx)
206        *idx = -1;
207    if (crit)
208        *crit = -1;
209    return NULL;
210}
211
212/*
213 * This function is a general extension append, replace and delete utility.
214 * The precise operation is governed by the 'flags' value. The 'crit' and
215 * 'value' arguments (if relevant) are the extensions internal structure.
216 */
217
218int X509V3_add1_i2d(STACK_OF(X509_EXTENSION) **x, int nid, void *value,
219                    int crit, unsigned long flags)
220{
221    int errcode, extidx = -1;
222    X509_EXTENSION *ext = NULL, *extmp;
223    STACK_OF(X509_EXTENSION) *ret = NULL;
224    unsigned long ext_op = flags & X509V3_ADD_OP_MASK;
225
226    /*
227     * If appending we don't care if it exists, otherwise look for existing
228     * extension.
229     */
230    if (ext_op != X509V3_ADD_APPEND)
231        extidx = X509v3_get_ext_by_NID(*x, nid, -1);
232
233    /* See if extension exists */
234    if (extidx >= 0) {
235        /* If keep existing, nothing to do */
236        if (ext_op == X509V3_ADD_KEEP_EXISTING)
237            return 1;
238        /* If default then its an error */
239        if (ext_op == X509V3_ADD_DEFAULT) {
240            errcode = X509V3_R_EXTENSION_EXISTS;
241            goto err;
242        }
243        /* If delete, just delete it */
244        if (ext_op == X509V3_ADD_DELETE) {
245            extmp = sk_X509_EXTENSION_delete(*x, extidx);
246            if (extmp == NULL)
247                return -1;
248            X509_EXTENSION_free(extmp);
249            return 1;
250        }
251    } else {
252        /*
253         * If replace existing or delete, error since extension must exist
254         */
255        if ((ext_op == X509V3_ADD_REPLACE_EXISTING) ||
256            (ext_op == X509V3_ADD_DELETE)) {
257            errcode = X509V3_R_EXTENSION_NOT_FOUND;
258            goto err;
259        }
260    }
261
262    /*
263     * If we get this far then we have to create an extension: could have
264     * some flags for alternative encoding schemes...
265     */
266
267    ext = X509V3_EXT_i2d(nid, crit, value);
268
269    if (!ext) {
270        ERR_raise(ERR_LIB_X509V3, X509V3_R_ERROR_CREATING_EXTENSION);
271        return 0;
272    }
273
274    /* If extension exists replace it.. */
275    if (extidx >= 0) {
276        extmp = sk_X509_EXTENSION_value(*x, extidx);
277        X509_EXTENSION_free(extmp);
278        if (!sk_X509_EXTENSION_set(*x, extidx, ext))
279            return -1;
280        return 1;
281    }
282
283    ret = *x;
284    if (*x == NULL
285        && (ret = sk_X509_EXTENSION_new_null()) == NULL)
286        goto m_fail;
287    if (!sk_X509_EXTENSION_push(ret, ext))
288        goto m_fail;
289
290    *x = ret;
291    return 1;
292
293 m_fail:
294    /* ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE); */
295    if (ret != *x)
296        sk_X509_EXTENSION_free(ret);
297    X509_EXTENSION_free(ext);
298    return -1;
299
300 err:
301    if (!(flags & X509V3_ADD_SILENT))
302        ERR_raise(ERR_LIB_X509V3, errcode);
303    return 0;
304}
305