1 /*
2 * Copyright 2008-2021 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the OpenSSL license (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 #include <openssl/asn1.h>
11 #include <openssl/asn1t.h>
12 #include <openssl/bio.h>
13 #include <openssl/err.h>
14
15 #include <stdio.h>
16
17 /* Experimental NDEF ASN1 BIO support routines */
18
19 /*
20 * The usage is quite simple, initialize an ASN1 structure, get a BIO from it
21 * then any data written through the BIO will end up translated to
22 * appropriate format on the fly. The data is streamed out and does *not*
23 * need to be all held in memory at once. When the BIO is flushed the output
24 * is finalized and any signatures etc written out. The BIO is a 'proper'
25 * BIO and can handle non blocking I/O correctly. The usage is simple. The
26 * implementation is *not*...
27 */
28
29 /* BIO support data stored in the ASN1 BIO ex_arg */
30
31 typedef struct ndef_aux_st {
32 /* ASN1 structure this BIO refers to */
33 ASN1_VALUE *val;
34 const ASN1_ITEM *it;
35 /* Top of the BIO chain */
36 BIO *ndef_bio;
37 /* Output BIO */
38 BIO *out;
39 /* Boundary where content is inserted */
40 unsigned char **boundary;
41 /* DER buffer start */
42 unsigned char *derbuf;
43 } NDEF_SUPPORT;
44
45 static int ndef_prefix(BIO *b, unsigned char **pbuf, int *plen, void *parg);
46 static int ndef_prefix_free(BIO *b, unsigned char **pbuf, int *plen,
47 void *parg);
48 static int ndef_suffix(BIO *b, unsigned char **pbuf, int *plen, void *parg);
49 static int ndef_suffix_free(BIO *b, unsigned char **pbuf, int *plen,
50 void *parg);
51
BIO_new_NDEF(BIO * out,ASN1_VALUE * val,const ASN1_ITEM * it)52 BIO *BIO_new_NDEF(BIO *out, ASN1_VALUE *val, const ASN1_ITEM *it)
53 {
54 NDEF_SUPPORT *ndef_aux = NULL;
55 BIO *asn_bio = NULL;
56 const ASN1_AUX *aux = it->funcs;
57 ASN1_STREAM_ARG sarg;
58
59 if (!aux || !aux->asn1_cb) {
60 ASN1err(ASN1_F_BIO_NEW_NDEF, ASN1_R_STREAMING_NOT_SUPPORTED);
61 return NULL;
62 }
63 ndef_aux = OPENSSL_zalloc(sizeof(*ndef_aux));
64 asn_bio = BIO_new(BIO_f_asn1());
65 if (ndef_aux == NULL || asn_bio == NULL)
66 goto err;
67
68 /* ASN1 bio needs to be next to output BIO */
69 out = BIO_push(asn_bio, out);
70 if (out == NULL)
71 goto err;
72
73 BIO_asn1_set_prefix(asn_bio, ndef_prefix, ndef_prefix_free);
74 BIO_asn1_set_suffix(asn_bio, ndef_suffix, ndef_suffix_free);
75
76 /*
77 * Now let callback prepends any digest, cipher etc BIOs ASN1 structure
78 * needs.
79 */
80
81 sarg.out = out;
82 sarg.ndef_bio = NULL;
83 sarg.boundary = NULL;
84
85 if (aux->asn1_cb(ASN1_OP_STREAM_PRE, &val, it, &sarg) <= 0)
86 goto err;
87
88 ndef_aux->val = val;
89 ndef_aux->it = it;
90 ndef_aux->ndef_bio = sarg.ndef_bio;
91 ndef_aux->boundary = sarg.boundary;
92 ndef_aux->out = out;
93
94 BIO_ctrl(asn_bio, BIO_C_SET_EX_ARG, 0, ndef_aux);
95
96 return sarg.ndef_bio;
97
98 err:
99 BIO_free(asn_bio);
100 OPENSSL_free(ndef_aux);
101 return NULL;
102 }
103
ndef_prefix(BIO * b,unsigned char ** pbuf,int * plen,void * parg)104 static int ndef_prefix(BIO *b, unsigned char **pbuf, int *plen, void *parg)
105 {
106 NDEF_SUPPORT *ndef_aux;
107 unsigned char *p;
108 int derlen;
109
110 if (!parg)
111 return 0;
112
113 ndef_aux = *(NDEF_SUPPORT **)parg;
114
115 derlen = ASN1_item_ndef_i2d(ndef_aux->val, NULL, ndef_aux->it);
116 if (derlen < 0)
117 return 0;
118 if ((p = OPENSSL_malloc(derlen)) == NULL) {
119 ASN1err(ASN1_F_NDEF_PREFIX, ERR_R_MALLOC_FAILURE);
120 return 0;
121 }
122
123 ndef_aux->derbuf = p;
124 *pbuf = p;
125 derlen = ASN1_item_ndef_i2d(ndef_aux->val, &p, ndef_aux->it);
126
127 if (!*ndef_aux->boundary)
128 return 0;
129
130 *plen = *ndef_aux->boundary - *pbuf;
131
132 return 1;
133 }
134
ndef_prefix_free(BIO * b,unsigned char ** pbuf,int * plen,void * parg)135 static int ndef_prefix_free(BIO *b, unsigned char **pbuf, int *plen,
136 void *parg)
137 {
138 NDEF_SUPPORT *ndef_aux;
139
140 if (!parg)
141 return 0;
142
143 ndef_aux = *(NDEF_SUPPORT **)parg;
144
145 if (ndef_aux == NULL)
146 return 0;
147
148 OPENSSL_free(ndef_aux->derbuf);
149
150 ndef_aux->derbuf = NULL;
151 *pbuf = NULL;
152 *plen = 0;
153 return 1;
154 }
155
ndef_suffix_free(BIO * b,unsigned char ** pbuf,int * plen,void * parg)156 static int ndef_suffix_free(BIO *b, unsigned char **pbuf, int *plen,
157 void *parg)
158 {
159 NDEF_SUPPORT **pndef_aux = (NDEF_SUPPORT **)parg;
160 if (!ndef_prefix_free(b, pbuf, plen, parg))
161 return 0;
162 OPENSSL_free(*pndef_aux);
163 *pndef_aux = NULL;
164 return 1;
165 }
166
ndef_suffix(BIO * b,unsigned char ** pbuf,int * plen,void * parg)167 static int ndef_suffix(BIO *b, unsigned char **pbuf, int *plen, void *parg)
168 {
169 NDEF_SUPPORT *ndef_aux;
170 unsigned char *p;
171 int derlen;
172 const ASN1_AUX *aux;
173 ASN1_STREAM_ARG sarg;
174
175 if (!parg)
176 return 0;
177
178 ndef_aux = *(NDEF_SUPPORT **)parg;
179
180 aux = ndef_aux->it->funcs;
181
182 /* Finalize structures */
183 sarg.ndef_bio = ndef_aux->ndef_bio;
184 sarg.out = ndef_aux->out;
185 sarg.boundary = ndef_aux->boundary;
186 if (aux->asn1_cb(ASN1_OP_STREAM_POST,
187 &ndef_aux->val, ndef_aux->it, &sarg) <= 0)
188 return 0;
189
190 derlen = ASN1_item_ndef_i2d(ndef_aux->val, NULL, ndef_aux->it);
191 if ((p = OPENSSL_malloc(derlen)) == NULL) {
192 ASN1err(ASN1_F_NDEF_SUFFIX, ERR_R_MALLOC_FAILURE);
193 return 0;
194 }
195
196 ndef_aux->derbuf = p;
197 *pbuf = p;
198 derlen = ASN1_item_ndef_i2d(ndef_aux->val, &p, ndef_aux->it);
199
200 if (!*ndef_aux->boundary)
201 return 0;
202 *pbuf = *ndef_aux->boundary;
203 *plen = derlen - (*ndef_aux->boundary - ndef_aux->derbuf);
204
205 return 1;
206 }
207