xref: /openbsd/lib/libcrypto/asn1/bio_ndef.c (revision 859caa33)
1 /* $OpenBSD: bio_ndef.c,v 1.24 2023/07/28 09:58:30 tb Exp $ */
2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
3  * project.
4  */
5 /* ====================================================================
6  * Copyright (c) 2008 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  */
54 
55 #include <stdio.h>
56 
57 #include <openssl/asn1.h>
58 #include <openssl/asn1t.h>
59 #include <openssl/bio.h>
60 #include <openssl/err.h>
61 
62 #include "asn1_local.h"
63 
64 int BIO_asn1_set_prefix(BIO *b, asn1_ps_func *prefix, asn1_ps_func *prefix_free);
65 int BIO_asn1_set_suffix(BIO *b, asn1_ps_func *suffix, asn1_ps_func *suffix_free);
66 
67 /* Experimental NDEF ASN1 BIO support routines */
68 
69 /* The usage is quite simple, initialize an ASN1 structure,
70  * get a BIO from it then any data written through the BIO
71  * will end up translated to approptiate format on the fly.
72  * The data is streamed out and does *not* need to be
73  * all held in memory at once.
74  *
75  * When the BIO is flushed the output is finalized and any
76  * signatures etc written out.
77  *
78  * The BIO is a 'proper' BIO and can handle non blocking I/O
79  * correctly.
80  *
81  * The usage is simple. The implementation is *not*...
82  */
83 
84 /* BIO support data stored in the ASN1 BIO ex_arg */
85 
86 typedef struct ndef_aux_st {
87 	/* ASN1 structure this BIO refers to */
88 	ASN1_VALUE *val;
89 	const ASN1_ITEM *it;
90 	/* Top of the BIO chain */
91 	BIO *ndef_bio;
92 	/* Output BIO */
93 	BIO *out;
94 	/* Boundary where content is inserted */
95 	unsigned char **boundary;
96 	/* DER buffer start */
97 	unsigned char *derbuf;
98 } NDEF_SUPPORT;
99 
100 static int ndef_prefix(BIO *b, unsigned char **pbuf, int *plen, void *parg);
101 static int ndef_prefix_free(BIO *b, unsigned char **pbuf, int *plen, void *parg);
102 static int ndef_suffix(BIO *b, unsigned char **pbuf, int *plen, void *parg);
103 static int ndef_suffix_free(BIO *b, unsigned char **pbuf, int *plen, void *parg);
104 
105 BIO *
BIO_new_NDEF(BIO * out,ASN1_VALUE * val,const ASN1_ITEM * it)106 BIO_new_NDEF(BIO *out, ASN1_VALUE *val, const ASN1_ITEM *it)
107 {
108 	NDEF_SUPPORT *ndef_aux = NULL;
109 	BIO *asn_bio = NULL, *pop_bio = NULL;
110 	const ASN1_AUX *aux = it->funcs;
111 	ASN1_STREAM_ARG sarg;
112 
113 	if (aux == NULL || aux->asn1_cb == NULL) {
114 		ASN1error(ASN1_R_STREAMING_NOT_SUPPORTED);
115 		goto err;
116 	}
117 
118 	if ((asn_bio = BIO_new(BIO_f_asn1())) == NULL)
119 		goto err;
120 
121 	if (BIO_push(asn_bio, out) == NULL)
122 		goto err;
123 	pop_bio = asn_bio;
124 
125 	/*
126 	 * Set up prefix and suffix handlers first. This ensures that ndef_aux
127 	 * is freed as part of asn_bio once it is the asn_bio's ex_arg.
128 	 */
129 	if (BIO_asn1_set_prefix(asn_bio, ndef_prefix, ndef_prefix_free) <= 0)
130 		goto err;
131 	if (BIO_asn1_set_suffix(asn_bio, ndef_suffix, ndef_suffix_free) <= 0)
132 		goto err;
133 
134 	/*
135 	 * Allocate early to avoid the tricky cleanup after the asn1_cb().
136 	 * Ownership of ndef_aux is transferred to asn_bio in BIO_ctrl().
137 	 * Keep a reference to populate it after callback success.
138 	 */
139 	if ((ndef_aux = calloc(1, sizeof(*ndef_aux))) == NULL)
140 		goto err;
141 	if (BIO_ctrl(asn_bio, BIO_C_SET_EX_ARG, 0, ndef_aux) <= 0) {
142 		free(ndef_aux);
143 		goto err;
144 	}
145 
146 	/*
147 	 * The callback prepends BIOs to the chain starting at asn_bio for
148 	 * digest, cipher, etc. The resulting chain starts at sarg.ndef_bio.
149 	 */
150 
151 	sarg.out = asn_bio;
152 	sarg.ndef_bio = NULL;
153 	sarg.boundary = NULL;
154 
155 	if (aux->asn1_cb(ASN1_OP_STREAM_PRE, &val, it, &sarg) <= 0)
156 		goto err;
157 
158 	ndef_aux->val = val;
159 	ndef_aux->it = it;
160 	ndef_aux->ndef_bio = sarg.ndef_bio;
161 	ndef_aux->boundary = sarg.boundary;
162 	ndef_aux->out = asn_bio;
163 
164 	return sarg.ndef_bio;
165 
166  err:
167 	BIO_pop(pop_bio);
168 	BIO_free(asn_bio);
169 
170 	return NULL;
171 }
172 
173 static int
ndef_prefix(BIO * b,unsigned char ** pbuf,int * plen,void * parg)174 ndef_prefix(BIO *b, unsigned char **pbuf, int *plen, void *parg)
175 {
176 	NDEF_SUPPORT *ndef_aux;
177 	unsigned char *p = NULL;
178 	int derlen;
179 
180 	if (!parg)
181 		return 0;
182 
183 	ndef_aux = *(NDEF_SUPPORT **)parg;
184 
185 	if ((derlen = ASN1_item_ndef_i2d(ndef_aux->val, &p, ndef_aux->it)) <= 0)
186 		return 0;
187 
188 	ndef_aux->derbuf = p;
189 	*pbuf = p;
190 
191 	if (*ndef_aux->boundary == NULL)
192 		return 0;
193 
194 	*plen = *ndef_aux->boundary - *pbuf;
195 
196 	return 1;
197 }
198 
199 static int
ndef_prefix_free(BIO * b,unsigned char ** pbuf,int * plen,void * parg)200 ndef_prefix_free(BIO *b, unsigned char **pbuf, int *plen, void *parg)
201 {
202 	NDEF_SUPPORT **pndef_aux = parg;
203 
204 	if (pndef_aux == NULL || *pndef_aux == NULL)
205 		return 0;
206 
207 	free((*pndef_aux)->derbuf);
208 	(*pndef_aux)->derbuf = NULL;
209 
210 	*pbuf = NULL;
211 	*plen = 0;
212 
213 	return 1;
214 }
215 
216 static int
ndef_suffix_free(BIO * b,unsigned char ** pbuf,int * plen,void * parg)217 ndef_suffix_free(BIO *b, unsigned char **pbuf, int *plen, void *parg)
218 {
219 	NDEF_SUPPORT **pndef_aux = parg;
220 
221 	/* Ensure ndef_prefix_free() won't fail, so we won't leak *pndef_aux. */
222 	if (pndef_aux == NULL || *pndef_aux == NULL)
223 		return 0;
224 	if (!ndef_prefix_free(b, pbuf, plen, parg))
225 		return 0;
226 
227 	free(*pndef_aux);
228 	*pndef_aux = NULL;
229 
230 	return 1;
231 }
232 
233 static int
ndef_suffix(BIO * b,unsigned char ** pbuf,int * plen,void * parg)234 ndef_suffix(BIO *b, unsigned char **pbuf, int *plen, void *parg)
235 {
236 	NDEF_SUPPORT *ndef_aux;
237 	unsigned char *p = NULL;
238 	int derlen;
239 	const ASN1_AUX *aux;
240 	ASN1_STREAM_ARG sarg;
241 
242 	if (!parg)
243 		return 0;
244 
245 	ndef_aux = *(NDEF_SUPPORT **)parg;
246 
247 	aux = ndef_aux->it->funcs;
248 
249 	/* Finalize structures */
250 	sarg.ndef_bio = ndef_aux->ndef_bio;
251 	sarg.out = ndef_aux->out;
252 	sarg.boundary = ndef_aux->boundary;
253 	if (aux->asn1_cb(ASN1_OP_STREAM_POST,
254 	    &ndef_aux->val, ndef_aux->it, &sarg) <= 0)
255 		return 0;
256 
257 	if ((derlen = ASN1_item_ndef_i2d(ndef_aux->val, &p, ndef_aux->it)) <= 0)
258 		return 0;
259 
260 	ndef_aux->derbuf = p;
261 	*pbuf = p;
262 
263 	if (*ndef_aux->boundary == NULL)
264 		return 0;
265 
266 	*pbuf = *ndef_aux->boundary;
267 	*plen = derlen - (*ndef_aux->boundary - ndef_aux->derbuf);
268 
269 	return 1;
270 }
271