xref: /openbsd/lib/libcrypto/asn1/tasn_fre.c (revision 131e1732)
1 /* $OpenBSD: tasn_fre.c,v 1.24 2024/12/11 11:22:06 tb Exp $ */
2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
3  * project 2000.
4  */
5 /* ====================================================================
6  * Copyright (c) 2000 The OpenSSL Project.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in
17  *    the documentation and/or other materials provided with the
18  *    distribution.
19  *
20  * 3. All advertising materials mentioning features or use of this
21  *    software must display the following acknowledgment:
22  *    "This product includes software developed by the OpenSSL Project
23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
24  *
25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26  *    endorse or promote products derived from this software without
27  *    prior written permission. For written permission, please contact
28  *    licensing@OpenSSL.org.
29  *
30  * 5. Products derived from this software may not be called "OpenSSL"
31  *    nor may "OpenSSL" appear in their names without prior written
32  *    permission of the OpenSSL Project.
33  *
34  * 6. Redistributions of any form whatsoever must retain the following
35  *    acknowledgment:
36  *    "This product includes software developed by the OpenSSL Project
37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
38  *
39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50  * OF THE POSSIBILITY OF SUCH DAMAGE.
51  * ====================================================================
52  *
53  * This product includes cryptographic software written by Eric Young
54  * (eay@cryptsoft.com).  This product includes software written by Tim
55  * Hudson (tjh@cryptsoft.com).
56  *
57  */
58 
59 
60 #include <stddef.h>
61 #include <openssl/asn1.h>
62 #include <openssl/asn1t.h>
63 #include <openssl/objects.h>
64 
65 #include "asn1_local.h"
66 
67 static void asn1_item_free(ASN1_VALUE **pval, const ASN1_ITEM *it);
68 
69 /* Free up an ASN1 structure */
70 
71 void
ASN1_item_free(ASN1_VALUE * val,const ASN1_ITEM * it)72 ASN1_item_free(ASN1_VALUE *val, const ASN1_ITEM *it)
73 {
74 	asn1_item_free(&val, it);
75 }
76 LCRYPTO_ALIAS(ASN1_item_free);
77 
78 void
ASN1_item_ex_free(ASN1_VALUE ** pval,const ASN1_ITEM * it)79 ASN1_item_ex_free(ASN1_VALUE **pval, const ASN1_ITEM *it)
80 {
81 	asn1_item_free(pval, it);
82 }
83 LCRYPTO_ALIAS(ASN1_item_ex_free);
84 
85 static void
asn1_item_free(ASN1_VALUE ** pval,const ASN1_ITEM * it)86 asn1_item_free(ASN1_VALUE **pval, const ASN1_ITEM *it)
87 {
88 	const ASN1_TEMPLATE *tt = NULL, *seqtt;
89 	const ASN1_EXTERN_FUNCS *ef;
90 	const ASN1_AUX *aux = it->funcs;
91 	ASN1_aux_cb *asn1_cb = NULL;
92 	int i;
93 
94 	if (pval == NULL)
95 		return;
96 	/* For primitive types *pval may be something other than C pointer. */
97 	if (it->itype != ASN1_ITYPE_PRIMITIVE && *pval == NULL)
98 		return;
99 
100 	if (aux != NULL && aux->asn1_cb != NULL)
101 		asn1_cb = aux->asn1_cb;
102 
103 	switch (it->itype) {
104 	case ASN1_ITYPE_PRIMITIVE:
105 		if (it->templates)
106 			ASN1_template_free(pval, it->templates);
107 		else
108 			ASN1_primitive_free(pval, it);
109 		break;
110 
111 	case ASN1_ITYPE_MSTRING:
112 		ASN1_primitive_free(pval, it);
113 		break;
114 
115 	case ASN1_ITYPE_CHOICE:
116 		if (asn1_cb) {
117 			i = asn1_cb(ASN1_OP_FREE_PRE, pval, it, NULL);
118 			if (i == 2)
119 				return;
120 		}
121 		i = asn1_get_choice_selector(pval, it);
122 		if ((i >= 0) && (i < it->tcount)) {
123 			ASN1_VALUE **pchval;
124 			tt = it->templates + i;
125 			pchval = asn1_get_field_ptr(pval, tt);
126 			ASN1_template_free(pchval, tt);
127 		}
128 		if (asn1_cb)
129 			asn1_cb(ASN1_OP_FREE_POST, pval, it, NULL);
130 		free(*pval);
131 		*pval = NULL;
132 		break;
133 
134 	case ASN1_ITYPE_EXTERN:
135 		ef = it->funcs;
136 		if (ef && ef->asn1_ex_free)
137 			ef->asn1_ex_free(pval, it);
138 		break;
139 
140 	case ASN1_ITYPE_NDEF_SEQUENCE:
141 	case ASN1_ITYPE_SEQUENCE:
142 		if (asn1_do_lock(pval, -1, it) > 0)
143 			return;
144 		if (asn1_cb) {
145 			i = asn1_cb(ASN1_OP_FREE_PRE, pval, it, NULL);
146 			if (i == 2)
147 				return;
148 		}
149 		asn1_enc_cleanup(pval, it);
150 		/* If we free up as normal we will invalidate any
151 		 * ANY DEFINED BY field and we wont be able to
152 		 * determine the type of the field it defines. So
153 		 * free up in reverse order.
154 		 */
155 		for (i = it->tcount - 1; i >= 0; i--) {
156 			ASN1_VALUE **pseqval;
157 			seqtt = asn1_do_adb(pval, &it->templates[i], 0);
158 			if (!seqtt)
159 				continue;
160 			pseqval = asn1_get_field_ptr(pval, seqtt);
161 			ASN1_template_free(pseqval, seqtt);
162 		}
163 		if (asn1_cb)
164 			asn1_cb(ASN1_OP_FREE_POST, pval, it, NULL);
165 		free(*pval);
166 		*pval = NULL;
167 		break;
168 	}
169 }
170 
171 void
ASN1_template_free(ASN1_VALUE ** pval,const ASN1_TEMPLATE * tt)172 ASN1_template_free(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt)
173 {
174 	int i;
175 	if (tt->flags & ASN1_TFLG_SK_MASK) {
176 		STACK_OF(ASN1_VALUE) *sk = (STACK_OF(ASN1_VALUE) *)*pval;
177 		for (i = 0; i < sk_ASN1_VALUE_num(sk); i++) {
178 			ASN1_VALUE *vtmp;
179 			vtmp = sk_ASN1_VALUE_value(sk, i);
180 			asn1_item_free(&vtmp, tt->item);
181 		}
182 		sk_ASN1_VALUE_free(sk);
183 		*pval = NULL;
184 	} else
185 		asn1_item_free(pval, tt->item);
186 }
187 
188 void
ASN1_primitive_free(ASN1_VALUE ** pval,const ASN1_ITEM * it)189 ASN1_primitive_free(ASN1_VALUE **pval, const ASN1_ITEM *it)
190 {
191 	int utype;
192 
193 	if (it != NULL && it->funcs != NULL) {
194 		const ASN1_PRIMITIVE_FUNCS *pf = it->funcs;
195 
196 		pf->prim_free(pval, it);
197 		return;
198 	}
199 
200 	/* Special case: if 'it' is NULL free contents of ASN1_TYPE */
201 	if (!it) {
202 		ASN1_TYPE *typ = (ASN1_TYPE *)*pval;
203 		utype = typ->type;
204 		pval = &typ->value.asn1_value;
205 		if (!*pval)
206 			return;
207 	} else if (it->itype == ASN1_ITYPE_MSTRING) {
208 		utype = -1;
209 		if (!*pval)
210 			return;
211 	} else {
212 		utype = it->utype;
213 		if ((utype != V_ASN1_BOOLEAN) && !*pval)
214 			return;
215 	}
216 
217 	switch (utype) {
218 	case V_ASN1_OBJECT:
219 		ASN1_OBJECT_free((ASN1_OBJECT *)*pval);
220 		break;
221 
222 	case V_ASN1_BOOLEAN:
223 		if (it)
224 			*(ASN1_BOOLEAN *)pval = it->size;
225 		else
226 			*(ASN1_BOOLEAN *)pval = -1;
227 		return;
228 
229 	case V_ASN1_NULL:
230 		break;
231 
232 	case V_ASN1_ANY:
233 		ASN1_primitive_free(pval, NULL);
234 		free(*pval);
235 		break;
236 
237 	default:
238 		ASN1_STRING_free((ASN1_STRING *)*pval);
239 		break;
240 	}
241 	*pval = NULL;
242 }
243