crypto/asn1/bio_ndef.c

   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() */
  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
 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
 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     OPENSSL_free(ndef_aux->derbuf);
 147
 148     ndef_aux->derbuf = NULL;
 149     *pbuf = NULL;
 150     *plen = 0;
 151     return 1;
 152 }
 153
 154 static int ndef_suffix_free(BIO *b, unsigned char **pbuf, int *plen,
 155                             void *parg)
 156 {
 157     NDEF_SUPPORT **pndef_aux = (NDEF_SUPPORT **)parg;
 158     if (!ndef_prefix_free(b, pbuf, plen, parg))
 159         return 0;
 160     OPENSSL_free(*pndef_aux);
 161     *pndef_aux = NULL;
 162     return 1;
 163 }
 164
 165 static int ndef_suffix(BIO *b, unsigned char **pbuf, int *plen, void *parg)
 166 {
 167     NDEF_SUPPORT *ndef_aux;
 168     unsigned char *p;
 169     int derlen;
 170     const ASN1_AUX *aux;
 171     ASN1_STREAM_ARG sarg;
 172
 173     if (parg == NULL)
 174         return 0;
 175
 176     ndef_aux = *(NDEF_SUPPORT **)parg;
 177
 178     aux = ndef_aux->it->funcs;
 179
 180     /* Finalize structures */
 181     sarg.ndef_bio = ndef_aux->ndef_bio;
 182     sarg.out = ndef_aux->out;
 183     sarg.boundary = ndef_aux->boundary;
 184     if (aux->asn1_cb(ASN1_OP_STREAM_POST,
 185                      &ndef_aux->val, ndef_aux->it, &sarg) <= 0)
 186         return 0;
 187
 188     derlen = ASN1_item_ndef_i2d(ndef_aux->val, NULL, ndef_aux->it);
 189     if (derlen < 0)
 190         return 0;
 191     if ((p = OPENSSL_malloc(derlen)) == NULL) {
 192         ERR_raise(ERR_LIB_ASN1, 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 == NULL)
 201         return 0;
 202     *pbuf = *ndef_aux->boundary;
 203     *plen = derlen - (*ndef_aux->boundary - ndef_aux->derbuf);
 204
 205     return 1;
 206 }