1/*
2 * Copyright 2008-2018 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
31typedef 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
45static int ndef_prefix(BIO *b, unsigned char **pbuf, int *plen, void *parg);
46static int ndef_prefix_free(BIO *b, unsigned char **pbuf, int *plen,
47 void *parg);
48static int ndef_suffix(BIO *b, unsigned char **pbuf, int *plen, void *parg);
49static 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() */
53BIO *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 ASN1err(ASN1_F_BIO_NEW_NDEF, 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
105static 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 ((p = OPENSSL_malloc(derlen)) == NULL) {
118 ASN1err(ASN1_F_NDEF_PREFIX, ERR_R_MALLOC_FAILURE);
119 return 0;
120 }
121
122 ndef_aux->derbuf = p;
123 *pbuf = p;
124 derlen = ASN1_item_ndef_i2d(ndef_aux->val, &p, ndef_aux->it);
125
126 if (*ndef_aux->boundary == NULL)
127 return 0;
128
129 *plen = *ndef_aux->boundary - *pbuf;
130
131 return 1;
132}
133
134static int ndef_prefix_free(BIO *b, unsigned char **pbuf, int *plen,
135 void *parg)
136{
137 NDEF_SUPPORT *ndef_aux;
138
139 if (parg == NULL)
140 return 0;
141
142 ndef_aux = *(NDEF_SUPPORT **)parg;
143
144 OPENSSL_free(ndef_aux->derbuf);
145
146 ndef_aux->derbuf = NULL;
147 *pbuf = NULL;
148 *plen = 0;
149 return 1;
150}
151
152static int ndef_suffix_free(BIO *b, unsigned char **pbuf, int *plen,
153 void *parg)
154{
155 NDEF_SUPPORT **pndef_aux = (NDEF_SUPPORT **)parg;
156 if (!ndef_prefix_free(b, pbuf, plen, parg))
157 return 0;
158 OPENSSL_free(*pndef_aux);
159 *pndef_aux = NULL;
160 return 1;
161}
162
163static int ndef_suffix(BIO *b, unsigned char **pbuf, int *plen, void *parg)
164{
165 NDEF_SUPPORT *ndef_aux;
166 unsigned char *p;
167 int derlen;
168 const ASN1_AUX *aux;
169 ASN1_STREAM_ARG sarg;
170
171 if (parg == NULL)
172 return 0;
173
174 ndef_aux = *(NDEF_SUPPORT **)parg;
175
176 aux = ndef_aux->it->funcs;
177
178 /* Finalize structures */
179 sarg.ndef_bio = ndef_aux->ndef_bio;
180 sarg.out = ndef_aux->out;
181 sarg.boundary = ndef_aux->boundary;
182 if (aux->asn1_cb(ASN1_OP_STREAM_POST,
183 &ndef_aux->val, ndef_aux->it, &sarg) <= 0)
184 return 0;
185
186 derlen = ASN1_item_ndef_i2d(ndef_aux->val, NULL, ndef_aux->it);
187 if (derlen < 0)
188 return 0;
189 if ((p = OPENSSL_malloc(derlen)) == NULL) {
190 ASN1err(ASN1_F_NDEF_SUFFIX, ERR_R_MALLOC_FAILURE);
191 return 0;
192 }
193
194 ndef_aux->derbuf = p;
195 *pbuf = p;
196 derlen = ASN1_item_ndef_i2d(ndef_aux->val, &p, ndef_aux->it);
197
198 if (*ndef_aux->boundary == NULL)
199 return 0;
200 *pbuf = *ndef_aux->boundary;
201 *plen = derlen - (*ndef_aux->boundary - ndef_aux->derbuf);
202
203 return 1;
204}
205