1 /* $OpenBSD: tasn_utl.c,v 1.10 2014/06/12 15:49:27 deraadt Exp $ */
2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
3  * project 2000.
4  */
5 /* ====================================================================
6  * Copyright (c) 2000-2004 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 #include <stddef.h>
60 #include <string.h>
61 #include <openssl/asn1.h>
62 #include <openssl/asn1t.h>
63 #include <openssl/objects.h>
64 #include <openssl/err.h>
65 
66 /* Utility functions for manipulating fields and offsets */
67 
68 /* Add 'offset' to 'addr' */
69 #define offset2ptr(addr, offset) (void *)(((char *) addr) + offset)
70 
71 /* Given an ASN1_ITEM CHOICE type return
72  * the selector value
73  */
74 
75 int
76 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
87 asn1_set_choice_selector(ASN1_VALUE **pval, int value, const ASN1_ITEM *it)
88 {
89 	int *sel, ret;
90 	sel = offset2ptr(*pval, it->utype);
91 	ret = *sel;
92 	*sel = value;
93 	return ret;
94 }
95 
96 /* Do reference counting. The value 'op' decides what to do.
97  * if it is +1 then the count is incremented. If op is 0 count is
98  * set to 1. If op is -1 count is decremented and the return value
99  * is the current refrence count or 0 if no reference count exists.
100  */
101 
102 int
103 asn1_do_lock(ASN1_VALUE **pval, int op, const ASN1_ITEM *it)
104 {
105 	const ASN1_AUX *aux;
106 	int *lck, ret;
107 
108 	if ((it->itype != ASN1_ITYPE_SEQUENCE) &&
109 	    (it->itype != ASN1_ITYPE_NDEF_SEQUENCE))
110 		return 0;
111 	aux = it->funcs;
112 	if (!aux || !(aux->flags & ASN1_AFLG_REFCOUNT))
113 		return 0;
114 	lck = offset2ptr(*pval, aux->ref_offset);
115 	if (op == 0) {
116 		*lck = 1;
117 		return 1;
118 	}
119 	ret = CRYPTO_add(lck, op, aux->ref_lock);
120 	return ret;
121 }
122 
123 static ASN1_ENCODING *
124 asn1_get_enc_ptr(ASN1_VALUE **pval, const ASN1_ITEM *it)
125 {
126 	const ASN1_AUX *aux;
127 
128 	if (!pval || !*pval)
129 		return NULL;
130 	aux = it->funcs;
131 	if (!aux || !(aux->flags & ASN1_AFLG_ENCODING))
132 		return NULL;
133 	return offset2ptr(*pval, aux->enc_offset);
134 }
135 
136 void
137 asn1_enc_init(ASN1_VALUE **pval, const ASN1_ITEM *it)
138 {
139 	ASN1_ENCODING *enc;
140 
141 	enc = asn1_get_enc_ptr(pval, it);
142 	if (enc) {
143 		enc->enc = NULL;
144 		enc->len = 0;
145 		enc->modified = 1;
146 	}
147 }
148 
149 void
150 asn1_enc_free(ASN1_VALUE **pval, const ASN1_ITEM *it)
151 {
152 	ASN1_ENCODING *enc;
153 
154 	enc = asn1_get_enc_ptr(pval, it);
155 	if (enc) {
156 		free(enc->enc);
157 		enc->enc = NULL;
158 		enc->len = 0;
159 		enc->modified = 1;
160 	}
161 }
162 
163 int
164 asn1_enc_save(ASN1_VALUE **pval, const unsigned char *in, int inlen,
165     const ASN1_ITEM *it)
166 {
167 	ASN1_ENCODING *enc;
168 
169 	enc = asn1_get_enc_ptr(pval, it);
170 	if (!enc)
171 		return 1;
172 
173 	free(enc->enc);
174 	enc->enc = malloc(inlen);
175 	if (!enc->enc)
176 		return 0;
177 	memcpy(enc->enc, in, inlen);
178 	enc->len = inlen;
179 	enc->modified = 0;
180 
181 	return 1;
182 }
183 
184 int
185 asn1_enc_restore(int *len, unsigned char **out, ASN1_VALUE **pval,
186     const ASN1_ITEM *it)
187 {
188 	ASN1_ENCODING *enc;
189 
190 	enc = asn1_get_enc_ptr(pval, it);
191 	if (!enc || enc->modified)
192 		return 0;
193 	if (out) {
194 		memcpy(*out, enc->enc, enc->len);
195 		*out += enc->len;
196 	}
197 	if (len)
198 		*len = enc->len;
199 	return 1;
200 }
201 
202 /* Given an ASN1_TEMPLATE get a pointer to a field */
203 ASN1_VALUE **
204 asn1_get_field_ptr(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt)
205 {
206 	ASN1_VALUE **pvaltmp;
207 
208 	if (tt->flags & ASN1_TFLG_COMBINE)
209 		return pval;
210 	pvaltmp = offset2ptr(*pval, tt->offset);
211 	/* NOTE for BOOLEAN types the field is just a plain
212  	 * int so we can't return int **, so settle for
213 	 * (int *).
214 	 */
215 	return pvaltmp;
216 }
217 
218 /* Handle ANY DEFINED BY template, find the selector, look up
219  * the relevant ASN1_TEMPLATE in the table and return it.
220  */
221 
222 const ASN1_TEMPLATE *
223 asn1_do_adb(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt, int nullerr)
224 {
225 	const ASN1_ADB *adb;
226 	const ASN1_ADB_TABLE *atbl;
227 	long selector;
228 	ASN1_VALUE **sfld;
229 	int i;
230 
231 	if (!(tt->flags & ASN1_TFLG_ADB_MASK))
232 		return tt;
233 
234 	/* Else ANY DEFINED BY ... get the table */
235 	adb = (const ASN1_ADB *)tt->item;
236 
237 	/* Get the selector field */
238 	sfld = offset2ptr(*pval, adb->offset);
239 
240 	/* Check if NULL */
241 	if (!sfld) {
242 		if (!adb->null_tt)
243 			goto err;
244 		return adb->null_tt;
245 	}
246 
247 	/* Convert type to a long:
248 	 * NB: don't check for NID_undef here because it
249 	 * might be a legitimate value in the table
250 	 */
251 	if (tt->flags & ASN1_TFLG_ADB_OID)
252 		selector = OBJ_obj2nid((ASN1_OBJECT *)*sfld);
253 	else
254 		selector = ASN1_INTEGER_get((ASN1_INTEGER *)*sfld);
255 
256 	/* Try to find matching entry in table
257 	 * Maybe should check application types first to
258 	 * allow application override? Might also be useful
259 	 * to have a flag which indicates table is sorted and
260 	 * we can do a binary search. For now stick to a
261 	 * linear search.
262 	 */
263 
264 	for (atbl = adb->tbl, i = 0; i < adb->tblcount; i++, atbl++)
265 		if (atbl->value == selector)
266 			return &atbl->tt;
267 
268 	/* FIXME: need to search application table too */
269 
270 	/* No match, return default type */
271 	if (!adb->default_tt)
272 		goto err;
273 	return adb->default_tt;
274 
275 err:
276 	/* FIXME: should log the value or OID of unsupported type */
277 	if (nullerr)
278 		ASN1err(ASN1_F_ASN1_DO_ADB,
279 		    ASN1_R_UNSUPPORTED_ANY_DEFINED_BY_TYPE);
280 	return NULL;
281 }
282