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#include <asn_application.h>
#include <asn_internal.h>
#include <per_decoder.h>
/*
* Decode a "Production of a complete encoding", X.691#10.1.
* The complete encoding contains at least one byte, and is an integral
* multiple of 8 bytes.
*/
asn_dec_rval_t
uper_decode_complete(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td, void **sptr, const void *buffer, size_t size) {
asn_dec_rval_t rval;
rval = uper_decode(opt_codec_ctx, td, sptr, buffer, size, 0, 0);
if(rval.consumed) {
/*
* We've always given 8-aligned data,
* so convert bits to integral bytes.
*/
rval.consumed += 7;
rval.consumed >>= 3;
} else if(rval.code == RC_OK) {
if(size) {
if(((uint8_t *)buffer)[0] == 0) {
rval.consumed = 1; /* 1 byte */
} else {
ASN_DEBUG("Expecting single zeroed byte");
rval.code = RC_FAIL;
}
} else {
/* Must contain at least 8 bits. */
rval.code = RC_WMORE;
}
}
return rval;
}
asn_dec_rval_t
uper_decode(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td, void **sptr, const void *buffer, size_t size, int skip_bits, int unused_bits) {
asn_codec_ctx_t s_codec_ctx;
asn_dec_rval_t rval;
asn_per_data_t pd;
if(skip_bits < 0 || skip_bits > 7
|| unused_bits < 0 || unused_bits > 7
|| (unused_bits > 0 && !size))
_ASN_DECODE_FAILED;
/*
* Stack checker requires that the codec context
* must be allocated on the stack.
*/
if(opt_codec_ctx) {
if(opt_codec_ctx->max_stack_size) {
s_codec_ctx = *opt_codec_ctx;
opt_codec_ctx = &s_codec_ctx;
}
} else {
/* If context is not given, be security-conscious anyway */
memset(&s_codec_ctx, 0, sizeof(s_codec_ctx));
s_codec_ctx.max_stack_size = _ASN_DEFAULT_STACK_MAX;
opt_codec_ctx = &s_codec_ctx;
}
/* Fill in the position indicator */
memset(&pd, 0, sizeof(pd));
pd.buffer = (const uint8_t *)buffer;
pd.nboff = skip_bits;
pd.nbits = 8 * size - unused_bits; /* 8 is CHAR_BIT from <limits.h> */
if(pd.nboff > pd.nbits)
_ASN_DECODE_FAILED;
/*
* Invoke type-specific decoder.
*/
if(!td->uper_decoder)
_ASN_DECODE_FAILED; /* PER is not compiled in */
rval = td->uper_decoder(opt_codec_ctx, td, 0, sptr, &pd);
if(rval.code == RC_OK) {
/* Return the number of consumed bits */
rval.consumed = ((pd.buffer - (const uint8_t *)buffer) << 3)
+ pd.nboff - skip_bits;
ASN_DEBUG("PER decoding consumed %d, counted %d",
rval.consumed, pd.moved);
assert(rval.consumed == pd.moved);
} else {
/* PER codec is not a restartable */
rval.consumed = 0;
}
return rval;
}