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/*
* Copyright 2008-2023 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <openssl/asn1.h>
#include <openssl/asn1t.h>
#include <openssl/bio.h>
#include <openssl/err.h>
#include <stdio.h>
/* Experimental NDEF ASN1 BIO support routines */
/*
* The usage is quite simple, initialize an ASN1 structure, get a BIO from it
* then any data written through the BIO will end up translated to
* appropriate format on the fly. The data is streamed out and does *not*
* need to be all held in memory at once. When the BIO is flushed the output
* is finalized and any signatures etc written out. The BIO is a 'proper'
* BIO and can handle non blocking I/O correctly. The usage is simple. The
* implementation is *not*...
*/
/* BIO support data stored in the ASN1 BIO ex_arg */
typedef struct ndef_aux_st {
/* ASN1 structure this BIO refers to */
ASN1_VALUE *val;
const ASN1_ITEM *it;
/* Top of the BIO chain */
BIO *ndef_bio;
/* Output BIO */
BIO *out;
/* Boundary where content is inserted */
unsigned char **boundary;
/* DER buffer start */
unsigned char *derbuf;
} NDEF_SUPPORT;
static int ndef_prefix(BIO *b, unsigned char **pbuf, int *plen, void *parg);
static int ndef_prefix_free(BIO *b, unsigned char **pbuf, int *plen,
void *parg);
static int ndef_suffix(BIO *b, unsigned char **pbuf, int *plen, void *parg);
static int ndef_suffix_free(BIO *b, unsigned char **pbuf, int *plen,
void *parg);
/*
* On success, the returned BIO owns the input BIO as part of its BIO chain.
* On failure, NULL is returned and the input BIO is owned by the caller.
*
* Unfortunately cannot constify this due to CMS_stream() and PKCS7_stream()
*/
BIO *BIO_new_NDEF(BIO *out, ASN1_VALUE *val, const ASN1_ITEM *it)
{
NDEF_SUPPORT *ndef_aux = NULL;
BIO *asn_bio = NULL;
const ASN1_AUX *aux = it->funcs;
ASN1_STREAM_ARG sarg;
BIO *pop_bio = NULL;
if (!aux || !aux->asn1_cb) {
ERR_raise(ERR_LIB_ASN1, ASN1_R_STREAMING_NOT_SUPPORTED);
return NULL;
}
ndef_aux = OPENSSL_zalloc(sizeof(*ndef_aux));
asn_bio = BIO_new(BIO_f_asn1());
if (ndef_aux == NULL || asn_bio == NULL)
goto err;
/* ASN1 bio needs to be next to output BIO */
out = BIO_push(asn_bio, out);
if (out == NULL)
goto err;
pop_bio = asn_bio;
if (BIO_asn1_set_prefix(asn_bio, ndef_prefix, ndef_prefix_free) <= 0
|| BIO_asn1_set_suffix(asn_bio, ndef_suffix, ndef_suffix_free) <= 0
|| BIO_ctrl(asn_bio, BIO_C_SET_EX_ARG, 0, ndef_aux) <= 0)
goto err;
/*
* Now let the callback prepend any digest, cipher, etc., that the BIO's
* ASN1 structure needs.
*/
sarg.out = out;
sarg.ndef_bio = NULL;
sarg.boundary = NULL;
/*
* The asn1_cb(), must not have mutated asn_bio on error, leaving it in the
* middle of some partially built, but not returned BIO chain.
*/
if (aux->asn1_cb(ASN1_OP_STREAM_PRE, &val, it, &sarg) <= 0) {
/*
* ndef_aux is now owned by asn_bio so we must not free it in the err
* clean up block
*/
ndef_aux = NULL;
goto err;
}
/*
* We must not fail now because the callback has prepended additional
* BIOs to the chain
*/
ndef_aux->val = val;
ndef_aux->it = it;
ndef_aux->ndef_bio = sarg.ndef_bio;
ndef_aux->boundary = sarg.boundary;
ndef_aux->out = out;
return sarg.ndef_bio;
err:
/* BIO_pop() is NULL safe */
(void)BIO_pop(pop_bio);
BIO_free(asn_bio);
OPENSSL_free(ndef_aux);
return NULL;
}
static int ndef_prefix(BIO *b, unsigned char **pbuf, int *plen, void *parg)
{
NDEF_SUPPORT *ndef_aux;
unsigned char *p;
int derlen;
if (parg == NULL)
return 0;
ndef_aux = *(NDEF_SUPPORT **)parg;
derlen = ASN1_item_ndef_i2d(ndef_aux->val, NULL, ndef_aux->it);
if (derlen < 0)
return 0;
if ((p = OPENSSL_malloc(derlen)) == NULL)
return 0;
ndef_aux->derbuf = p;
*pbuf = p;
ASN1_item_ndef_i2d(ndef_aux->val, &p, ndef_aux->it);
if (*ndef_aux->boundary == NULL)
return 0;
*plen = *ndef_aux->boundary - *pbuf;
return 1;
}
static int ndef_prefix_free(BIO *b, unsigned char **pbuf, int *plen,
void *parg)
{
NDEF_SUPPORT *ndef_aux;
if (parg == NULL)
return 0;
ndef_aux = *(NDEF_SUPPORT **)parg;
if (ndef_aux == NULL)
return 0;
OPENSSL_free(ndef_aux->derbuf);
ndef_aux->derbuf = NULL;
*pbuf = NULL;
*plen = 0;
return 1;
}
static int ndef_suffix_free(BIO *b, unsigned char **pbuf, int *plen,
void *parg)
{
NDEF_SUPPORT **pndef_aux = (NDEF_SUPPORT **)parg;
if (!ndef_prefix_free(b, pbuf, plen, parg))
return 0;
OPENSSL_free(*pndef_aux);
*pndef_aux = NULL;
return 1;
}
static int ndef_suffix(BIO *b, unsigned char **pbuf, int *plen, void *parg)
{
NDEF_SUPPORT *ndef_aux;
unsigned char *p;
int derlen;
const ASN1_AUX *aux;
ASN1_STREAM_ARG sarg;
if (parg == NULL)
return 0;
ndef_aux = *(NDEF_SUPPORT **)parg;
aux = ndef_aux->it->funcs;
/* Finalize structures */
sarg.ndef_bio = ndef_aux->ndef_bio;
sarg.out = ndef_aux->out;
sarg.boundary = ndef_aux->boundary;
if (aux->asn1_cb(ASN1_OP_STREAM_POST,
&ndef_aux->val, ndef_aux->it, &sarg) <= 0)
return 0;
derlen = ASN1_item_ndef_i2d(ndef_aux->val, NULL, ndef_aux->it);
if (derlen < 0)
return 0;
if ((p = OPENSSL_malloc(derlen)) == NULL)
return 0;
ndef_aux->derbuf = p;
*pbuf = p;
derlen = ASN1_item_ndef_i2d(ndef_aux->val, &p, ndef_aux->it);
if (*ndef_aux->boundary == NULL)
return 0;
*pbuf = *ndef_aux->boundary;
*plen = derlen - (*ndef_aux->boundary - ndef_aux->derbuf);
return 1;
}
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