1 /*
2 * Copyright 2008-2021 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (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
52 /* unfortunately cannot constify this due to CMS_stream() and PKCS7_stream() */
BIO_new_NDEF(BIO * out,ASN1_VALUE * val,const ASN1_ITEM * it)53 BIO *BIO_new_NDEF(BIO *out, ASN1_VALUE *val, const ASN1_ITEM *it)
54 {
55 NDEF_SUPPORT *ndef_aux = NULL;
56 BIO *asn_bio = NULL;
57 const ASN1_AUX *aux = it->funcs;
58 ASN1_STREAM_ARG sarg;
59
60 if (!aux || !aux->asn1_cb) {
61 ERR_raise(ERR_LIB_ASN1, ASN1_R_STREAMING_NOT_SUPPORTED);
62 return NULL;
63 }
64 ndef_aux = OPENSSL_zalloc(sizeof(*ndef_aux));
65 asn_bio = BIO_new(BIO_f_asn1());
66 if (ndef_aux == NULL || asn_bio == NULL)
67 goto err;
68
69 /* ASN1 bio needs to be next to output BIO */
70 out = BIO_push(asn_bio, out);
71 if (out == NULL)
72 goto err;
73
74 BIO_asn1_set_prefix(asn_bio, ndef_prefix, ndef_prefix_free);
75 BIO_asn1_set_suffix(asn_bio, ndef_suffix, ndef_suffix_free);
76
77 /*
78 * Now let callback prepends any digest, cipher etc BIOs ASN1 structure
79 * needs.
80 */
81
82 sarg.out = out;
83 sarg.ndef_bio = NULL;
84 sarg.boundary = NULL;
85
86 if (aux->asn1_cb(ASN1_OP_STREAM_PRE, &val, it, &sarg) <= 0)
87 goto err;
88
89 ndef_aux->val = val;
90 ndef_aux->it = it;
91 ndef_aux->ndef_bio = sarg.ndef_bio;
92 ndef_aux->boundary = sarg.boundary;
93 ndef_aux->out = out;
94
95 BIO_ctrl(asn_bio, BIO_C_SET_EX_ARG, 0, ndef_aux);
96
97 return sarg.ndef_bio;
98
99 err:
100 BIO_free(asn_bio);
101 OPENSSL_free(ndef_aux);
102 return NULL;
103 }
104
ndef_prefix(BIO * b,unsigned char ** pbuf,int * plen,void * parg)105 static int ndef_prefix(BIO *b, unsigned char **pbuf, int *plen, void *parg)
106 {
107 NDEF_SUPPORT *ndef_aux;
108 unsigned char *p;
109 int derlen;
110
111 if (parg == NULL)
112 return 0;
113
114 ndef_aux = *(NDEF_SUPPORT **)parg;
115
116 derlen = ASN1_item_ndef_i2d(ndef_aux->val, NULL, ndef_aux->it);
117 if (derlen < 0)
118 return 0;
119 if ((p = OPENSSL_malloc(derlen)) == NULL) {
120 ERR_raise(ERR_LIB_ASN1, ERR_R_MALLOC_FAILURE);
121 return 0;
122 }
123
124 ndef_aux->derbuf = p;
125 *pbuf = p;
126 ASN1_item_ndef_i2d(ndef_aux->val, &p, ndef_aux->it);
127
128 if (*ndef_aux->boundary == NULL)
129 return 0;
130
131 *plen = *ndef_aux->boundary - *pbuf;
132
133 return 1;
134 }
135
ndef_prefix_free(BIO * b,unsigned char ** pbuf,int * plen,void * parg)136 static int ndef_prefix_free(BIO *b, unsigned char **pbuf, int *plen,
137 void *parg)
138 {
139 NDEF_SUPPORT *ndef_aux;
140
141 if (parg == NULL)
142 return 0;
143
144 ndef_aux = *(NDEF_SUPPORT **)parg;
145
146 if (ndef_aux == NULL)
147 return 0;
148
149 OPENSSL_free(ndef_aux->derbuf);
150
151 ndef_aux->derbuf = NULL;
152 *pbuf = NULL;
153 *plen = 0;
154 return 1;
155 }
156
ndef_suffix_free(BIO * b,unsigned char ** pbuf,int * plen,void * parg)157 static int ndef_suffix_free(BIO *b, unsigned char **pbuf, int *plen,
158 void *parg)
159 {
160 NDEF_SUPPORT **pndef_aux = (NDEF_SUPPORT **)parg;
161 if (!ndef_prefix_free(b, pbuf, plen, parg))
162 return 0;
163 OPENSSL_free(*pndef_aux);
164 *pndef_aux = NULL;
165 return 1;
166 }
167
ndef_suffix(BIO * b,unsigned char ** pbuf,int * plen,void * parg)168 static int ndef_suffix(BIO *b, unsigned char **pbuf, int *plen, void *parg)
169 {
170 NDEF_SUPPORT *ndef_aux;
171 unsigned char *p;
172 int derlen;
173 const ASN1_AUX *aux;
174 ASN1_STREAM_ARG sarg;
175
176 if (parg == NULL)
177 return 0;
178
179 ndef_aux = *(NDEF_SUPPORT **)parg;
180
181 aux = ndef_aux->it->funcs;
182
183 /* Finalize structures */
184 sarg.ndef_bio = ndef_aux->ndef_bio;
185 sarg.out = ndef_aux->out;
186 sarg.boundary = ndef_aux->boundary;
187 if (aux->asn1_cb(ASN1_OP_STREAM_POST,
188 &ndef_aux->val, ndef_aux->it, &sarg) <= 0)
189 return 0;
190
191 derlen = ASN1_item_ndef_i2d(ndef_aux->val, NULL, ndef_aux->it);
192 if (derlen < 0)
193 return 0;
194 if ((p = OPENSSL_malloc(derlen)) == NULL) {
195 ERR_raise(ERR_LIB_ASN1, ERR_R_MALLOC_FAILURE);
196 return 0;
197 }
198
199 ndef_aux->derbuf = p;
200 *pbuf = p;
201 derlen = ASN1_item_ndef_i2d(ndef_aux->val, &p, ndef_aux->it);
202
203 if (*ndef_aux->boundary == NULL)
204 return 0;
205 *pbuf = *ndef_aux->boundary;
206 *plen = derlen - (*ndef_aux->boundary - ndef_aux->derbuf);
207
208 return 1;
209 }
210
