xref: /openbsd-src/lib/libcrypto/asn1/tasn_utl.c (revision 8500990981f885cbe5e6a4958549cacc238b5ae6)
1 /* tasn_utl.c */
2 /* Written by Dr Stephen N Henson (shenson@bigfoot.com) 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 <string.h>
62 #include <openssl/asn1.h>
63 #include <openssl/asn1t.h>
64 #include <openssl/objects.h>
65 #include <openssl/err.h>
66 
67 /* Utility functions for manipulating fields and offsets */
68 
69 /* Add 'offset' to 'addr' */
70 #define offset2ptr(addr, offset) (void *)(((char *) addr) + offset)
71 
72 /* Given an ASN1_ITEM CHOICE type return
73  * the selector value
74  */
75 
76 int asn1_get_choice_selector(ASN1_VALUE **pval, const ASN1_ITEM *it)
77 {
78 	int *sel = offset2ptr(*pval, it->utype);
79 	return *sel;
80 }
81 
82 /* Given an ASN1_ITEM CHOICE type set
83  * the selector value, return old value.
84  */
85 
86 int asn1_set_choice_selector(ASN1_VALUE **pval, int value, const ASN1_ITEM *it)
87 {
88 	int *sel, ret;
89 	sel = offset2ptr(*pval, it->utype);
90 	ret = *sel;
91 	*sel = value;
92 	return ret;
93 }
94 
95 /* Do reference counting. The value 'op' decides what to do.
96  * if it is +1 then the count is incremented. If op is 0 count is
97  * set to 1. If op is -1 count is decremented and the return value
98  * is the current refrence count or 0 if no reference count exists.
99  */
100 
101 int asn1_do_lock(ASN1_VALUE **pval, int op, const ASN1_ITEM *it)
102 {
103 	const ASN1_AUX *aux;
104 	int *lck, ret;
105 	if(it->itype != ASN1_ITYPE_SEQUENCE) return 0;
106 	aux = it->funcs;
107 	if(!aux || !(aux->flags & ASN1_AFLG_REFCOUNT)) return 0;
108 	lck = offset2ptr(*pval, aux->ref_offset);
109 	if(op == 0) {
110 		*lck = 1;
111 		return 1;
112 	}
113 	ret = CRYPTO_add(lck, op, aux->ref_lock);
114 #ifdef REF_PRINT
115 	fprintf(stderr, "%s: Reference Count: %d\n", it->sname, *lck);
116 #endif
117 #ifdef REF_CHECK
118 	if(ret < 0)
119 		fprintf(stderr, "%s, bad reference count\n", it->sname);
120 #endif
121 	return ret;
122 }
123 
124 static ASN1_ENCODING *asn1_get_enc_ptr(ASN1_VALUE **pval, const ASN1_ITEM *it)
125 {
126 	const ASN1_AUX *aux;
127 	if(!pval || !*pval) return NULL;
128 	aux = it->funcs;
129 	if(!aux || !(aux->flags & ASN1_AFLG_ENCODING)) return NULL;
130 	return offset2ptr(*pval, aux->enc_offset);
131 }
132 
133 void asn1_enc_init(ASN1_VALUE **pval, const ASN1_ITEM *it)
134 {
135 	ASN1_ENCODING *enc;
136 	enc = asn1_get_enc_ptr(pval, it);
137 	if(enc) {
138 		enc->enc = NULL;
139 		enc->len = 0;
140 		enc->modified = 1;
141 	}
142 }
143 
144 void asn1_enc_free(ASN1_VALUE **pval, const ASN1_ITEM *it)
145 {
146 	ASN1_ENCODING *enc;
147 	enc = asn1_get_enc_ptr(pval, it);
148 	if(enc) {
149 		if(enc->enc) OPENSSL_free(enc->enc);
150 		enc->enc = NULL;
151 		enc->len = 0;
152 		enc->modified = 1;
153 	}
154 }
155 
156 int asn1_enc_save(ASN1_VALUE **pval, unsigned char *in, int inlen, const ASN1_ITEM *it)
157 {
158 	ASN1_ENCODING *enc;
159 	enc = asn1_get_enc_ptr(pval, it);
160 	if(!enc) return 1;
161 
162 	if(enc->enc) OPENSSL_free(enc->enc);
163 	enc->enc = OPENSSL_malloc(inlen);
164 	if(!enc->enc) return 0;
165 	memcpy(enc->enc, in, inlen);
166 	enc->len = inlen;
167 	enc->modified = 0;
168 
169 	return 1;
170 }
171 
172 int asn1_enc_restore(int *len, unsigned char **out, ASN1_VALUE **pval, const ASN1_ITEM *it)
173 {
174 	ASN1_ENCODING *enc;
175 	enc = asn1_get_enc_ptr(pval, it);
176 	if(!enc || enc->modified) return 0;
177 	if(out) {
178 		memcpy(*out, enc->enc, enc->len);
179 		*out += enc->len;
180 	}
181 	if(len) *len = enc->len;
182 	return 1;
183 }
184 
185 /* Given an ASN1_TEMPLATE get a pointer to a field */
186 ASN1_VALUE ** asn1_get_field_ptr(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt)
187 {
188 	ASN1_VALUE **pvaltmp;
189 	if(tt->flags & ASN1_TFLG_COMBINE) return pval;
190 	pvaltmp = offset2ptr(*pval, tt->offset);
191 	/* NOTE for BOOLEAN types the field is just a plain
192  	 * int so we can't return int **, so settle for
193 	 * (int *).
194 	 */
195 	return pvaltmp;
196 }
197 
198 /* Handle ANY DEFINED BY template, find the selector, look up
199  * the relevant ASN1_TEMPLATE in the table and return it.
200  */
201 
202 const ASN1_TEMPLATE *asn1_do_adb(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt, int nullerr)
203 {
204 	const ASN1_ADB *adb;
205 	const ASN1_ADB_TABLE *atbl;
206 	long selector;
207 	ASN1_VALUE **sfld;
208 	int i;
209 	if(!(tt->flags & ASN1_TFLG_ADB_MASK)) return tt;
210 
211 	/* Else ANY DEFINED BY ... get the table */
212 	adb = ASN1_ADB_ptr(tt->item);
213 
214 	/* Get the selector field */
215 	sfld = offset2ptr(*pval, adb->offset);
216 
217 	/* Check if NULL */
218 	if(!sfld) {
219 		if(!adb->null_tt) goto err;
220 		return adb->null_tt;
221 	}
222 
223 	/* Convert type to a long:
224 	 * NB: don't check for NID_undef here because it
225 	 * might be a legitimate value in the table
226 	 */
227 	if(tt->flags & ASN1_TFLG_ADB_OID)
228 		selector = OBJ_obj2nid((ASN1_OBJECT *)*sfld);
229 	else
230 		selector = ASN1_INTEGER_get((ASN1_INTEGER *)*sfld);
231 
232 	/* Try to find matching entry in table
233 	 * Maybe should check application types first to
234 	 * allow application override? Might also be useful
235 	 * to have a flag which indicates table is sorted and
236 	 * we can do a binary search. For now stick to a
237 	 * linear search.
238 	 */
239 
240 	for(atbl = adb->tbl, i = 0; i < adb->tblcount; i++, atbl++)
241 		if(atbl->value == selector) return &atbl->tt;
242 
243 	/* FIXME: need to search application table too */
244 
245 	/* No match, return default type */
246 	if(!adb->default_tt) goto err;
247 	return adb->default_tt;
248 
249 	err:
250 	/* FIXME: should log the value or OID of unsupported type */
251 	if(nullerr) ASN1err(ASN1_F_ASN1_DO_ADB, ASN1_R_UNSUPPORTED_ANY_DEFINED_BY_TYPE);
252 	return NULL;
253 }
254