/****************************************************************************
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**
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** Copyright (C) 2016 Intel Corporation
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**
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** Permission is hereby granted, free of charge, to any person obtaining a copy
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** of this software and associated documentation files (the "Software"), to deal
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** in the Software without restriction, including without limitation the rights
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** to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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** copies of the Software, and to permit persons to whom the Software is
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** furnished to do so, subject to the following conditions:
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**
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** The above copyright notice and this permission notice shall be included in
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** all copies or substantial portions of the Software.
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**
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** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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** IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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** FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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** AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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** LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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** OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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** THE SOFTWARE.
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**
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****************************************************************************/
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#define _BSD_SOURCE 1
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#define _DEFAULT_SOURCE 1
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#ifndef __STDC_LIMIT_MACROS
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# define __STDC_LIMIT_MACROS 1
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#endif
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#include "tinycbor/cbor.h"
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#include "tinycbor/cborconstants_p.h"
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#include "tinycbor/compilersupport_p.h"
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#include "tinycbor/extract_number_p.h"
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#include <assert.h>
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#include <string.h>
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#include <tinycbor/cbor_buf_reader.h>
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#include "tinycbor/assert_p.h" /* Always include last */
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#ifndef CBOR_PARSER_MAX_RECURSIONS
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# define CBOR_PARSER_MAX_RECURSIONS 1024
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#endif
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/**
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* \defgroup CborParsing Parsing CBOR streams
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* \brief Group of functions used to parse CBOR streams.
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*
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* TinyCBOR provides functions for pull-based stream parsing of a CBOR-encoded
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* payload. The main data type for the parsing is a CborValue, which behaves
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* like an iterator and can be used to extract the encoded data. It is first
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* initialized with a call to cbor_parser_init() and is usually used to extract
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* exactly one item, most often an array or map.
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*
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* Nested CborValue objects can be parsed using cbor_value_enter_container().
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* Each call to cbor_value_enter_container() must be matched by a call to
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* cbor_value_leave_container(), with the exact same parameters.
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*
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* The example below initializes a CborParser object, begins the parsing with a
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* CborValue and decodes a single integer:
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*
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* \code
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* int extract_int(const uint8_t *buffer, size_t len)
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* {
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* CborParser parser;
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* CborValue value;
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* int result;
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* cbor_parser_init(buffer, len, 0, &buffer, &value);
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* cbor_value_get_int(&value, &result);
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* return result;
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* }
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* \endcode
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*
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* The code above does no error checking, which means it assumes the data comes
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* from a source trusted to send one properly-encoded integer. The following
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* example does the exact same operation, but includes error parsing and
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* returns 0 on parsing failure:
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*
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* \code
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* int extract_int(const uint8_t *buffer, size_t len)
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* {
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* CborParser parser;
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* CborValue value;
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* int result;
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* if (cbor_parser_init(buffer, len, 0, &buffer, &value) != CborNoError)
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* return 0;
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* if (!cbor_value_is_integer(&value) ||
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* cbor_value_get_int(&value, &result) != CborNoError)
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* return 0;
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* return result;
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* }
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* \endcode
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*
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* Note, in the example above, that one can't distinguish a parsing failure
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* from an encoded value of zero. Reporting a parsing error is left as an
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* exercise to the reader.
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*
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* The code above does not execute a range-check either: it is possible that
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* the value decoded from the CBOR stream encodes a number larger than what can
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* be represented in a variable of type \c{int}. If detecting that case is
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* important, the code should call cbor_value_get_int_checked() instead.
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*
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* <h3 class="groupheader">Memory and parsing constraints</h3>
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*
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* TinyCBOR is designed to run with little memory and with minimal overhead.
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* Except where otherwise noted, the parser functions always run on constant
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* time (O(1)), do not recurse and never allocate memory (thus, stack usage is
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* bounded and is O(1)).
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*
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* <h3 class="groupheader">Error handling and preconditions</h3>
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*
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* All functions operating on a CborValue return a CborError condition, with
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* CborNoError standing for the normal situation in which no parsing error
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* occurred. All functions may return parsing errors in case the stream cannot
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* be decoded properly, be it due to corrupted data or due to reaching the end
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* of the input buffer.
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*
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* Error conditions must not be ignored. All decoder functions have undefined
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* behavior if called after an error has been reported, and may crash.
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*
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* Some functions are also documented to have preconditions, like
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* cbor_value_get_int() requiring that the input be an integral value.
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* Violation of preconditions also results in undefined behavior and the
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* program may crash.
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*/
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/**
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* \addtogroup CborParsing
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* @{
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*/
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/**
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* \struct CborValue
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*
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* This type contains one value parsed from the CBOR stream. Each CborValue
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* behaves as an iterator in a StAX-style parser.
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*
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* \if privatedocs
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* Implementation details: the CborValue contains these fields:
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* \list
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* \li ptr: pointer to the actual data
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* \li flags: flags from the decoder
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* \li extra: partially decoded integer value (0, 1 or 2 bytes)
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* \li remaining: remaining items in this collection after this item or UINT32_MAX if length is unknown
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* \endlist
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* \endif
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*/
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static CborError extract_length(const CborParser *parser,
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int *offset, size_t *len)
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{
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uint64_t v;
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CborError err = extract_number(parser, offset, &v);
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if (err) {
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*len = 0;
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return err;
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}
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*len = v;
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if (v != *len)
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return CborErrorDataTooLarge;
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return CborNoError;
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}
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static bool is_fixed_type(uint8_t type)
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{
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return type != CborTextStringType && type != CborByteStringType && type != CborArrayType &&
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type != CborMapType;
|
}
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|
static CborError preparse_value(CborValue *it)
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{
|
const CborParser *parser = it->parser;
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it->type = CborInvalidType;
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/* are we at the end? */
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if (it->offset == parser->end)
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return CborErrorUnexpectedEOF;
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|
uint8_t descriptor = parser->d->get8(parser->d, it->offset);
|
uint8_t type = descriptor & MajorTypeMask;
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it->type = type;
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it->flags = 0;
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it->extra = (descriptor &= SmallValueMask);
|
|
if (descriptor > Value64Bit) {
|
if (unlikely(descriptor != IndefiniteLength))
|
return type == CborSimpleType ? CborErrorUnknownType : CborErrorIllegalNumber;
|
if (likely(!is_fixed_type(type))) {
|
/* special case */
|
it->flags |= CborIteratorFlag_UnknownLength;
|
it->type = type;
|
return CborNoError;
|
}
|
return type == CborSimpleType ? CborErrorUnexpectedBreak : CborErrorIllegalNumber;
|
}
|
|
size_t bytesNeeded = descriptor < Value8Bit ? 0 : (1 << (descriptor - Value8Bit));
|
if (bytesNeeded + 1 > (size_t)(parser->end - it->offset))
|
return CborErrorUnexpectedEOF;
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|
uint8_t majortype = type >> MajorTypeShift;
|
if (majortype == NegativeIntegerType) {
|
it->flags |= CborIteratorFlag_NegativeInteger;
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it->type = CborIntegerType;
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} else if (majortype == SimpleTypesType) {
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switch (descriptor) {
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case FalseValue:
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it->extra = false;
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it->type = CborBooleanType;
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break;
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|
case SinglePrecisionFloat:
|
case DoublePrecisionFloat:
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it->flags |= CborIteratorFlag_IntegerValueTooLarge;
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/* fall through */
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case TrueValue:
|
case NullValue:
|
case UndefinedValue:
|
case HalfPrecisionFloat:
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it->type = parser->d->get8(parser->d, it->offset);
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break;
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|
case SimpleTypeInNextByte:
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it->extra = parser->d->get8(parser->d, it->offset + 1);
|
#ifndef CBOR_PARSER_NO_STRICT_CHECKS
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if (unlikely(it->extra < 32)) {
|
it->type = CborInvalidType;
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return CborErrorIllegalSimpleType;
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}
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#endif
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break;
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|
case 28:
|
case 29:
|
case 30:
|
case Break:
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assert(false); /* these conditions can't be reached */
|
return CborErrorUnexpectedBreak;
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}
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return CborNoError;
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}
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|
/* try to decode up to 16 bits */
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if (descriptor < Value8Bit)
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return CborNoError;
|
|
if (descriptor == Value8Bit)
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it->extra = parser->d->get8(parser->d, it->offset + 1);
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else if (descriptor == Value16Bit)
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it->extra = parser->d->get16(parser->d, it->offset + 1);
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else
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it->flags |= CborIteratorFlag_IntegerValueTooLarge; /* Value32Bit or Value64Bit */
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return CborNoError;
|
}
|
|
static CborError preparse_next_value(CborValue *it)
|
{
|
if (it->remaining != UINT32_MAX) {
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/* don't decrement the item count if the current item is tag: they don't count */
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if (it->type != CborTagType && !--it->remaining) {
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it->type = CborInvalidType;
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return CborNoError;
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}
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} else if (it->remaining == UINT32_MAX && it->offset != it->parser->end &&
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it->parser->d->get8(it->parser->d, it->offset) == (uint8_t)BreakByte) {
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/* end of map or array */
|
++it->offset;
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it->type = CborInvalidType;
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it->remaining = 0;
|
return CborNoError;
|
}
|
|
return preparse_value(it);
|
}
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|
static CborError advance_internal(CborValue *it)
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{
|
uint64_t length;
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CborError err = extract_number(it->parser, &it->offset, &length);
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assert(err == CborNoError);
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if (it->type == CborByteStringType || it->type == CborTextStringType) {
|
assert(length == (size_t)length);
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assert((it->flags & CborIteratorFlag_UnknownLength) == 0);
|
it->offset += length;
|
}
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|
return preparse_next_value(it);
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}
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|
/** \internal
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*
|
* Decodes the CBOR integer value when it is larger than the 16 bits available
|
* in value->extra. This function requires that value->flags have the
|
* CborIteratorFlag_IntegerValueTooLarge flag set.
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*
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* This function is also used to extract single- and double-precision floating
|
* point values (SinglePrecisionFloat == Value32Bit and DoublePrecisionFloat ==
|
* Value64Bit).
|
*/
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uint64_t _cbor_value_decode_int64_internal(const CborValue *value)
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{
|
uint8_t val = value->parser->d->get8(value->parser->d, value->offset);
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assert(value->flags & CborIteratorFlag_IntegerValueTooLarge ||
|
value->type == CborFloatType || value->type == CborDoubleType);
|
|
/* since the additional information can only be Value32Bit or Value64Bit,
|
* we just need to test for the one bit those two options differ */
|
assert((val & SmallValueMask) == Value32Bit || (val & SmallValueMask) == Value64Bit);
|
if ((val & 1) == (Value32Bit & 1))
|
return value->parser->d->get32(value->parser->d, value->offset + 1);
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|
assert((val & SmallValueMask) == Value64Bit);
|
return value->parser->d->get64(value->parser->d, value->offset + 1);
|
}
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|
/**
|
* Initializes the CBOR parser for parsing \a size bytes beginning at \a
|
* buffer. Parsing will use flags set in \a flags. The iterator to the first
|
* element is returned in \a it.
|
*
|
* The \a parser structure needs to remain valid throughout the decoding
|
* process. It is not thread-safe to share one CborParser among multiple
|
* threads iterating at the same time, but the object can be copied so multiple
|
* threads can iterate.
|
*/
|
CborError cbor_parser_init(struct cbor_decoder_reader *d, int flags,
|
CborParser *parser, CborValue *it)
|
{
|
memset(parser, 0, sizeof(*parser));
|
parser->d = d;
|
parser->end = d->message_size;
|
parser->flags = flags;
|
it->parser = parser;
|
it->offset = 0;
|
it->remaining = 1;/* there's one type altogether, usually an array or map */
|
return preparse_value(it);
|
}
|
|
/**
|
* \fn bool cbor_value_at_end(const CborValue *it)
|
*
|
* Returns true if \a it has reached the end of the iteration, usually when
|
* advancing after the last item in an array or map.
|
*
|
* In the case of the outermost CborValue object, this function returns true
|
* after decoding a single element. A pointer to the first byte of the
|
* remaining data (if any) can be obtained with cbor_value_get_next_byte().
|
*
|
* \sa cbor_value_advance(), cbor_value_is_valid(), cbor_value_get_next_byte()
|
*/
|
|
/**
|
* \fn const uint8_t *cbor_value_get_next_byte(const CborValue *it)
|
*
|
* Returns a pointer to the next byte that would be decoded if this CborValue
|
* object were advanced.
|
*
|
* This function is useful if cbor_value_at_end() returns true for the
|
* outermost CborValue: the pointer returned is the first byte of the data
|
* remaining in the buffer, if any. Code can decide whether to begin decoding a
|
* new CBOR data stream from this point, or parse some other data appended to
|
* the same buffer.
|
*
|
* This function may be used even after a parsing error. If that occurred,
|
* then this function returns a pointer to where the parsing error occurred.
|
* Note that the error recovery is not precise and the pointer may not indicate
|
* the exact byte containing bad data.
|
*
|
* \sa cbor_value_at_end()
|
*/
|
|
/**
|
* \fn bool cbor_value_is_valid(const CborValue *it)
|
*
|
* Returns true if the iterator \a it contains a valid value. Invalid iterators
|
* happen when iteration reaches the end of a container (see \ref
|
* cbor_value_at_end()) or when a search function resulted in no matches.
|
*
|
* \sa cbor_value_advance(), cbor_valie_at_end(), cbor_value_get_type()
|
*/
|
|
/**
|
* Advances the CBOR value \a it by one fixed-size position. Fixed-size types
|
* are: integers, tags, simple types (including boolean, null and undefined
|
* values) and floating point types.
|
*
|
* If the type is not of fixed size, this function has undefined behavior. Code
|
* must be sure that the current type is one of the fixed-size types before
|
* calling this function. This function is provided because it can guarantee
|
* that runs in constant time (O(1)).
|
*
|
* If the caller is not able to determine whether the type is fixed or not, code
|
* can use the cbor_value_advance() function instead.
|
*
|
* \sa cbor_value_at_end(), cbor_value_advance(), cbor_value_enter_container(), cbor_value_leave_container()
|
*/
|
CborError cbor_value_advance_fixed(CborValue *it)
|
{
|
assert(it->type != CborInvalidType);
|
assert(is_fixed_type(it->type));
|
if (!it->remaining)
|
return CborErrorAdvancePastEOF;
|
return advance_internal(it);
|
}
|
|
static CborError advance_recursive(CborValue *it, int nestingLevel)
|
{
|
if (is_fixed_type(it->type))
|
return advance_internal(it);
|
|
if (!cbor_value_is_container(it)) {
|
size_t len = SIZE_MAX;
|
return _cbor_value_copy_string(it, NULL, &len, it);
|
}
|
|
/* map or array */
|
if (nestingLevel == CBOR_PARSER_MAX_RECURSIONS)
|
return CborErrorNestingTooDeep;
|
|
CborError err;
|
CborValue recursed;
|
err = cbor_value_enter_container(it, &recursed);
|
if (err)
|
return err;
|
while (!cbor_value_at_end(&recursed)) {
|
err = advance_recursive(&recursed, nestingLevel + 1);
|
if (err)
|
return err;
|
}
|
return cbor_value_leave_container(it, &recursed);
|
}
|
|
|
/**
|
* Advances the CBOR value \a it by one element, skipping over containers.
|
* Unlike cbor_value_advance_fixed(), this function can be called on a CBOR
|
* value of any type. However, if the type is a container (map or array) or a
|
* string with a chunked payload, this function will not run in constant time
|
* and will recurse into itself (it will run on O(n) time for the number of
|
* elements or chunks and will use O(n) memory for the number of nested
|
* containers).
|
*
|
* \sa cbor_value_at_end(), cbor_value_advance_fixed(), cbor_value_enter_container(), cbor_value_leave_container()
|
*/
|
CborError cbor_value_advance(CborValue *it)
|
{
|
assert(it->type != CborInvalidType);
|
if (!it->remaining)
|
return CborErrorAdvancePastEOF;
|
return advance_recursive(it, 0);
|
}
|
|
/**
|
* \fn bool cbor_value_is_tag(const CborValue *value)
|
*
|
* Returns true if the iterator \a value is valid and points to a CBOR tag.
|
*
|
* \sa cbor_value_get_tag(), cbor_value_skip_tag()
|
*/
|
|
/**
|
* \fn CborError cbor_value_get_tag(const CborValue *value, CborTag *result)
|
*
|
* Retrieves the CBOR tag value that \a value points to and stores it in \a
|
* result. If the iterator \a value does not point to a CBOR tag value, the
|
* behavior is undefined, so checking with \ref cbor_value_get_type or with
|
* \ref cbor_value_is_tag is recommended.
|
*
|
* \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_tag()
|
*/
|
|
/**
|
* Advances the CBOR value \a it until it no longer points to a tag. If \a it is
|
* already not pointing to a tag, then this function returns it unchanged.
|
*
|
* This function does not run in constant time: it will run on O(n) for n being
|
* the number of tags. It does use constant memory (O(1) memory requirements).
|
*
|
* \sa cbor_value_advance_fixed(), cbor_value_advance()
|
*/
|
CborError cbor_value_skip_tag(CborValue *it)
|
{
|
while (cbor_value_is_tag(it)) {
|
CborError err = cbor_value_advance_fixed(it);
|
if (err)
|
return err;
|
}
|
return CborNoError;
|
}
|
|
/**
|
* \fn bool cbor_value_is_container(const CborValue *it)
|
*
|
* Returns true if the \a it value is a container and requires recursion in
|
* order to decode (maps and arrays), false otherwise.
|
*/
|
|
/**
|
* Creates a CborValue iterator pointing to the first element of the container
|
* represented by \a it and saves it in \a recursed. The \a it container object
|
* needs to be kept and passed again to cbor_value_leave_container() in order
|
* to continue iterating past this container.
|
*
|
* The \a it CborValue iterator must point to a container.
|
*
|
* \sa cbor_value_is_container(), cbor_value_leave_container(), cbor_value_advance()
|
*/
|
CborError cbor_value_enter_container(const CborValue *it, CborValue *recursed)
|
{
|
CborError err;
|
assert(cbor_value_is_container(it));
|
*recursed = *it;
|
|
if (it->flags & CborIteratorFlag_UnknownLength) {
|
recursed->remaining = UINT32_MAX;
|
++recursed->offset;
|
err = preparse_value(recursed);
|
if (err != CborErrorUnexpectedBreak)
|
return err;
|
/* actually, break was expected here
|
* it's just an empty container */
|
++recursed->offset;
|
} else {
|
uint64_t len;
|
err = extract_number(recursed->parser, &recursed->offset, &len);
|
assert(err == CborNoError);
|
|
recursed->remaining = (uint32_t)len;
|
if (recursed->remaining != len || len == UINT32_MAX) {
|
/* back track the pointer to indicate where the error occurred */
|
recursed->offset = it->offset;
|
return CborErrorDataTooLarge;
|
}
|
if (recursed->type == CborMapType) {
|
/* maps have keys and values, so we need to multiply by 2 */
|
if (recursed->remaining > UINT32_MAX / 2) {
|
/* back track the pointer to indicate where the error occurred */
|
recursed->offset = it->offset;
|
return CborErrorDataTooLarge;
|
}
|
recursed->remaining *= 2;
|
}
|
if (len != 0)
|
return preparse_value(recursed);
|
}
|
|
/* the case of the empty container */
|
recursed->type = CborInvalidType;
|
recursed->remaining = 0;
|
return CborNoError;
|
}
|
|
/**
|
* Updates \a it to point to the next element after the container. The \a
|
* recursed object needs to point to the element obtained either by advancing
|
* the last element of the container (via cbor_value_advance(),
|
* cbor_value_advance_fixed(), a nested cbor_value_leave_container(), or the \c
|
* next pointer from cbor_value_copy_string() or cbor_value_dup_string()).
|
*
|
* The \a it and \a recursed parameters must be the exact same as passed to
|
* cbor_value_enter_container().
|
*
|
* \sa cbor_value_enter_container(), cbor_value_at_end()
|
*/
|
CborError cbor_value_leave_container(CborValue *it, const CborValue *recursed)
|
{
|
assert(cbor_value_is_container(it));
|
assert(recursed->type == CborInvalidType);
|
it->offset = recursed->offset;
|
return preparse_next_value(it);
|
}
|
|
|
/**
|
* \fn CborType cbor_value_get_type(const CborValue *value)
|
*
|
* Returns the type of the CBOR value that the iterator \a value points to. If
|
* \a value does not point to a valid value, this function returns \ref
|
* CborInvalidType.
|
*
|
* TinyCBOR also provides functions to test directly if a given CborValue object
|
* is of a given type, like cbor_value_is_text_string() and cbor_value_is_null().
|
*
|
* \sa cbor_value_is_valid()
|
*/
|
|
/**
|
* \fn bool cbor_value_is_null(const CborValue *value)
|
*
|
* Returns true if the iterator \a value is valid and points to a CBOR null type.
|
*
|
* \sa cbor_value_is_valid(), cbor_value_is_undefined()
|
*/
|
|
/**
|
* \fn bool cbor_value_is_undefined(const CborValue *value)
|
*
|
* Returns true if the iterator \a value is valid and points to a CBOR undefined type.
|
*
|
* \sa cbor_value_is_valid(), cbor_value_is_null()
|
*/
|
|
/**
|
* \fn bool cbor_value_is_boolean(const CborValue *value)
|
*
|
* Returns true if the iterator \a value is valid and points to a CBOR boolean
|
* type (true or false).
|
*
|
* \sa cbor_value_is_valid(), cbor_value_get_boolean()
|
*/
|
|
/**
|
* \fn CborError cbor_value_get_boolean(const CborValue *value, bool *result)
|
*
|
* Retrieves the boolean value that \a value points to and stores it in \a
|
* result. If the iterator \a value does not point to a boolean value, the
|
* behavior is undefined, so checking with \ref cbor_value_get_type or with
|
* \ref cbor_value_is_boolean is recommended.
|
*
|
* \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_boolean()
|
*/
|
|
/**
|
* \fn bool cbor_value_is_simple_type(const CborValue *value)
|
*
|
* Returns true if the iterator \a value is valid and points to a CBOR Simple Type
|
* type (other than true, false, null and undefined).
|
*
|
* \sa cbor_value_is_valid(), cbor_value_get_simple_type()
|
*/
|
|
/**
|
* \fn CborError cbor_value_get_simple_type(const CborValue *value, uint8_t *result)
|
*
|
* Retrieves the CBOR Simple Type value that \a value points to and stores it
|
* in \a result. If the iterator \a value does not point to a simple_type
|
* value, the behavior is undefined, so checking with \ref cbor_value_get_type
|
* or with \ref cbor_value_is_simple_type is recommended.
|
*
|
* \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_simple_type()
|
*/
|
|
/**
|
* \fn bool cbor_value_is_integer(const CborValue *value)
|
*
|
* Returns true if the iterator \a value is valid and points to a CBOR integer
|
* type.
|
*
|
* \sa cbor_value_is_valid(), cbor_value_get_int, cbor_value_get_int64, cbor_value_get_uint64, cbor_value_get_raw_integer
|
*/
|
|
/**
|
* \fn bool cbor_value_is_unsigned_integer(const CborValue *value)
|
*
|
* Returns true if the iterator \a value is valid and points to a CBOR unsigned
|
* integer type (positive values or zero).
|
*
|
* \sa cbor_value_is_valid(), cbor_value_get_uint64()
|
*/
|
|
/**
|
* \fn bool cbor_value_is_negative_integer(const CborValue *value)
|
*
|
* Returns true if the iterator \a value is valid and points to a CBOR negative
|
* integer type.
|
*
|
* \sa cbor_value_is_valid(), cbor_value_get_int, cbor_value_get_int64, cbor_value_get_raw_integer
|
*/
|
|
/**
|
* \fn CborError cbor_value_get_int(const CborValue *value, int *result)
|
*
|
* Retrieves the CBOR integer value that \a value points to and stores it in \a
|
* result. If the iterator \a value does not point to an integer value, the
|
* behavior is undefined, so checking with \ref cbor_value_get_type or with
|
* \ref cbor_value_is_integer is recommended.
|
*
|
* Note that this function does not do range-checking: integral values that do
|
* not fit in a variable of type \c{int} are silently truncated to fit. Use
|
* cbor_value_get_int_checked() that is not acceptable.
|
*
|
* \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_integer()
|
*/
|
|
/**
|
* \fn CborError cbor_value_get_int64(const CborValue *value, int64_t *result)
|
*
|
* Retrieves the CBOR integer value that \a value points to and stores it in \a
|
* result. If the iterator \a value does not point to an integer value, the
|
* behavior is undefined, so checking with \ref cbor_value_get_type or with
|
* \ref cbor_value_is_integer is recommended.
|
*
|
* Note that this function does not do range-checking: integral values that do
|
* not fit in a variable of type \c{int64_t} are silently truncated to fit. Use
|
* cbor_value_get_int64_checked() that is not acceptable.
|
*
|
* \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_integer()
|
*/
|
|
/**
|
* \fn CborError cbor_value_get_uint64(const CborValue *value, uint64_t *result)
|
*
|
* Retrieves the CBOR integer value that \a value points to and stores it in \a
|
* result. If the iterator \a value does not point to an unsigned integer
|
* value, the behavior is undefined, so checking with \ref cbor_value_get_type
|
* or with \ref cbor_value_is_unsigned_integer is recommended.
|
*
|
* \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_unsigned_integer()
|
*/
|
|
/**
|
* \fn CborError cbor_value_get_raw_integer(const CborValue *value, uint64_t *result)
|
*
|
* Retrieves the CBOR integer value that \a value points to and stores it in \a
|
* result. If the iterator \a value does not point to an integer value, the
|
* behavior is undefined, so checking with \ref cbor_value_get_type or with
|
* \ref cbor_value_is_integer is recommended.
|
*
|
* This function is provided because CBOR negative integers can assume values
|
* that cannot be represented with normal 64-bit integer variables.
|
*
|
* If the integer is unsigned (that is, if cbor_value_is_unsigned_integer()
|
* returns true), then \a result will contain the actual value. If the integer
|
* is negative, then \a result will contain the absolute value of that integer,
|
* minus one. That is, \c {actual = -result - 1}. On architectures using two's
|
* complement for representation of negative integers, it is equivalent to say
|
* that \a result will contain the bitwise negation of the actual value.
|
*
|
* \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_integer()
|
*/
|
|
/**
|
* Retrieves the CBOR integer value that \a value points to and stores it in \a
|
* result. If the iterator \a value does not point to an integer value, the
|
* behavior is undefined, so checking with \ref cbor_value_get_type or with
|
* \ref cbor_value_is_integer is recommended.
|
*
|
* Unlike cbor_value_get_int64(), this function performs a check to see if the
|
* stored integer fits in \a result without data loss. If the number is outside
|
* the valid range for the data type, this function returns the recoverable
|
* error CborErrorDataTooLarge. In that case, use either
|
* cbor_value_get_uint64() (if the number is positive) or
|
* cbor_value_get_raw_integer().
|
*
|
* \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_integer(), cbor_value_get_int64()
|
*/
|
CborError cbor_value_get_int64_checked(const CborValue *value, int64_t *result)
|
{
|
assert(cbor_value_is_integer(value));
|
uint64_t v = _cbor_value_extract_int64_helper(value);
|
|
/* Check before converting, as the standard says (C11 6.3.1.3 paragraph 3):
|
* "[if] the new type is signed and the value cannot be represented in it; either the
|
* result is implementation-defined or an implementation-defined signal is raised."
|
*
|
* The range for int64_t is -2^63 to 2^63-1 (int64_t is required to be
|
* two's complement, C11 7.20.1.1 paragraph 3), which in CBOR is
|
* represented the same way, differing only on the "sign bit" (the major
|
* type).
|
*/
|
|
if (unlikely(v > (uint64_t)INT64_MAX))
|
return CborErrorDataTooLarge;
|
|
*result = v;
|
if (value->flags & CborIteratorFlag_NegativeInteger)
|
*result = -*result - 1;
|
return CborNoError;
|
}
|
|
/**
|
* Retrieves the CBOR integer value that \a value points to and stores it in \a
|
* result. If the iterator \a value does not point to an integer value, the
|
* behavior is undefined, so checking with \ref cbor_value_get_type or with
|
* \ref cbor_value_is_integer is recommended.
|
*
|
* Unlike cbor_value_get_int(), this function performs a check to see if the
|
* stored integer fits in \a result without data loss. If the number is outside
|
* the valid range for the data type, this function returns the recoverable
|
* error CborErrorDataTooLarge. In that case, use one of the other integer
|
* functions to obtain the value.
|
*
|
* \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_integer(), cbor_value_get_int64(),
|
* cbor_value_get_uint64(), cbor_value_get_int64_checked(), cbor_value_get_raw_integer()
|
*/
|
CborError cbor_value_get_int_checked(const CborValue *value, int *result)
|
{
|
assert(cbor_value_is_integer(value));
|
uint64_t v = _cbor_value_extract_int64_helper(value);
|
|
/* Check before converting, as the standard says (C11 6.3.1.3 paragraph 3):
|
* "[if] the new type is signed and the value cannot be represented in it; either the
|
* result is implementation-defined or an implementation-defined signal is raised."
|
*
|
* But we can convert from signed to unsigned without fault (paragraph 2).
|
*
|
* The range for int is implementation-defined and int is not guaranteed use
|
* two's complement representation (int32_t is).
|
*/
|
|
if (value->flags & CborIteratorFlag_NegativeInteger) {
|
if (unlikely(v > (unsigned) -(INT_MIN + 1)))
|
return CborErrorDataTooLarge;
|
|
*result = v;
|
*result = -*result - 1;
|
} else {
|
if (unlikely(v > (uint64_t)INT_MAX))
|
return CborErrorDataTooLarge;
|
|
*result = v;
|
}
|
return CborNoError;
|
|
}
|
|
/**
|
* \fn bool cbor_value_is_length_known(const CborValue *value)
|
*
|
* Returns true if the length of this type is known without calculation. That
|
* is, if the length of this CBOR string, map or array is encoded in the data
|
* stream, this function returns true. If the length is not encoded, it returns
|
* false.
|
*
|
* If the length is known, code can call cbor_value_get_string_length(),
|
* cbor_value_get_array_length() or cbor_value_get_map_length() to obtain the
|
* length. If the length is not known but is necessary, code can use the
|
* cbor_value_calculate_string_length() function (no equivalent function is
|
* provided for maps and arrays).
|
*/
|
|
/**
|
* \fn bool cbor_value_is_text_string(const CborValue *value)
|
*
|
* Returns true if the iterator \a value is valid and points to a CBOR text
|
* string. CBOR text strings are UTF-8 encoded and usually contain
|
* human-readable text.
|
*
|
* \sa cbor_value_is_valid(), cbor_value_get_string_length(), cbor_value_calculate_string_length(),
|
* cbor_value_copy_text_string(), cbor_value_dup_text_string()
|
*/
|
|
/**
|
* \fn bool cbor_value_is_byte_string(const CborValue *value)
|
*
|
* Returns true if the iterator \a value is valid and points to a CBOR text
|
* string. CBOR byte strings are binary data with no specified encoding or
|
* format.
|
*
|
* \sa cbor_value_is_valid(), cbor_value_get_string_length(), cbor_value_calculate_string_length(),
|
* cbor_value_copy_byte_string(), cbor_value_dup_byte_string()
|
*/
|
|
/**
|
* \fn CborError cbor_value_get_string_length(const CborValue *value, size_t *length)
|
*
|
* Extracts the length of the byte or text string that \a value points to and
|
* stores it in \a result. If the iterator \a value does not point to a text
|
* string or a byte string, the behaviour is undefined, so checking with \ref
|
* cbor_value_get_type, with \ref cbor_value_is_text_string or \ref
|
* cbor_value_is_byte_string is recommended.
|
*
|
* If the length of this string is not encoded in the CBOR data stream, this
|
* function will return the recoverable error CborErrorUnknownLength. You may
|
* also check whether that is the case by using cbor_value_is_length_known().
|
*
|
* If the length of the string is required but the length was not encoded, use
|
* cbor_value_calculate_string_length(), but note that that function does not
|
* run in constant time.
|
*
|
* \note On 32-bit platforms, this function will return error condition of \ref
|
* CborErrorDataTooLarge if the stream indicates a length that is too big to
|
* fit in 32-bit.
|
*
|
* \sa cbor_value_is_valid(), cbor_value_is_length_known(), cbor_value_calculate_string_length()
|
*/
|
|
/**
|
* Calculates the length of the byte or text string that \a value points to and
|
* stores it in \a len. If the iterator \a value does not point to a text
|
* string or a byte string, the behaviour is undefined, so checking with \ref
|
* cbor_value_get_type, with \ref cbor_value_is_text_string or \ref
|
* cbor_value_is_byte_string is recommended.
|
*
|
* This function is different from cbor_value_get_string_length() in that it
|
* calculates the length even for strings sent in chunks. For that reason, this
|
* function may not run in constant time (it will run in O(n) time on the
|
* number of chunks). It does use constant memory (O(1)).
|
*
|
* \note On 32-bit platforms, this function will return error condition of \ref
|
* CborErrorDataTooLarge if the stream indicates a length that is too big to
|
* fit in 32-bit.
|
*
|
* \sa cbor_value_get_string_length(), cbor_value_copy_string(), cbor_value_is_length_known()
|
*/
|
CborError cbor_value_calculate_string_length(const CborValue *value, size_t *len)
|
{
|
*len = SIZE_MAX;
|
return _cbor_value_copy_string(value, NULL, len, NULL);
|
}
|
|
/* We return uintptr_t so that we can pass memcpy directly as the iteration
|
* function. The choice is to optimize for memcpy, which is used in the base
|
* parser API (cbor_value_copy_string), while memcmp is used in convenience API
|
* only. */
|
typedef uintptr_t (*IterateFunction)(struct cbor_decoder_reader *d, char *dst, int src_offset, size_t len);
|
|
static uintptr_t iterate_noop(struct cbor_decoder_reader *d, char *dst, int src_offset, size_t len)
|
{
|
(void)d;
|
(void)dst;
|
(void)src_offset;
|
(void)len;
|
return true;
|
}
|
|
static CborError iterate_string_chunks(const CborValue *value, char *buffer, size_t *buflen,
|
bool *result, CborValue *next, IterateFunction func)
|
{
|
assert(cbor_value_is_byte_string(value) || cbor_value_is_text_string(value));
|
|
size_t total;
|
CborError err;
|
int offset = value->offset;
|
if (cbor_value_is_length_known(value)) {
|
/* easy case: fixed length */
|
err = extract_length(value->parser, &offset, &total);
|
if (err)
|
return err;
|
if (total > (size_t)(value->parser->end - offset))
|
return CborErrorUnexpectedEOF;
|
if (total <= *buflen)
|
*result = !!func(value->parser->d, buffer, offset, total);
|
else
|
*result = false;
|
offset += total;
|
} else {
|
/* chunked */
|
++offset;
|
total = 0;
|
*result = true;
|
while (true) {
|
uint8_t val;
|
size_t chunkLen;
|
size_t newTotal;
|
|
if (offset == value->parser->end)
|
return CborErrorUnexpectedEOF;
|
|
val = value->parser->d->get8(value->parser->d, offset);
|
|
if (val == (uint8_t)BreakByte) {
|
++offset;
|
break;
|
}
|
|
/* is this the right type? */
|
if ((val & MajorTypeMask) != value->type)
|
return CborErrorIllegalType;
|
|
err = extract_length(value->parser, &offset, &chunkLen);
|
if (err)
|
return err;
|
|
if (unlikely(add_check_overflow(total, chunkLen, &newTotal)))
|
return CborErrorDataTooLarge;
|
|
if (chunkLen > (size_t)(value->parser->end - offset))
|
return CborErrorUnexpectedEOF;
|
|
if (*result && *buflen >= newTotal)
|
*result = !!func(value->parser->d, buffer + total, offset, chunkLen);
|
else
|
*result = false;
|
|
offset += chunkLen;
|
total = newTotal;
|
}
|
}
|
|
/* is there enough room for the ending NUL byte? */
|
if (*result && *buflen > total) {
|
/* we are just trying to write a NULL byte here,, but this is hard
|
* because this is called by function pointer with an abstract
|
* reader. Since this is the output buffer, we can assume that if
|
* we have a valid buffer its ok to write a NULL here */
|
if(buffer) {
|
*(buffer + total) = '\0';
|
}
|
}
|
*buflen = total;
|
|
if (next) {
|
*next = *value;
|
next->offset = offset;
|
return preparse_next_value(next);
|
}
|
return CborNoError;
|
}
|
|
/**
|
* \fn CborError cbor_value_copy_text_string(const CborValue *value, char *buffer, size_t *buflen, CborValue *next)
|
*
|
* Copies the string pointed by \a value into the buffer provided at \a buffer
|
* of \a buflen bytes. If \a buffer is a NULL pointer, this function will not
|
* copy anything and will only update the \a next value.
|
*
|
* If the iterator \a value does not point to a text string, the behaviour is
|
* undefined, so checking with \ref cbor_value_get_type or \ref
|
* cbor_value_is_text_string is recommended.
|
*
|
* If the provided buffer length was too small, this function returns an error
|
* condition of \ref CborErrorOutOfMemory. If you need to calculate the length
|
* of the string in order to preallocate a buffer, use
|
* cbor_value_calculate_string_length().
|
*
|
* On success, this function sets the number of bytes copied to \c{*buflen}. If
|
* the buffer is large enough, this function will insert a null byte after the
|
* last copied byte, to facilitate manipulation of text strings. That byte is
|
* not included in the returned value of \c{*buflen}.
|
*
|
* The \a next pointer, if not null, will be updated to point to the next item
|
* after this string. If \a value points to the last item, then \a next will be
|
* invalid.
|
*
|
* This function may not run in constant time (it will run in O(n) time on the
|
* number of chunks). It requires constant memory (O(1)).
|
*
|
* \note This function does not perform UTF-8 validation on the incoming text
|
* string.
|
*
|
* \sa cbor_value_dup_text_string(), cbor_value_copy_byte_string(), cbor_value_get_string_length(), cbor_value_calculate_string_length()
|
*/
|
|
/**
|
* \fn CborError cbor_value_copy_byte_string(const CborValue *value, uint8_t *buffer, size_t *buflen, CborValue *next)
|
*
|
* Copies the string pointed by \a value into the buffer provided at \a buffer
|
* of \a buflen bytes. If \a buffer is a NULL pointer, this function will not
|
* copy anything and will only update the \a next value.
|
*
|
* If the iterator \a value does not point to a byte string, the behaviour is
|
* undefined, so checking with \ref cbor_value_get_type or \ref
|
* cbor_value_is_byte_string is recommended.
|
*
|
* If the provided buffer length was too small, this function returns an error
|
* condition of \ref CborErrorOutOfMemory. If you need to calculate the length
|
* of the string in order to preallocate a buffer, use
|
* cbor_value_calculate_string_length().
|
*
|
* On success, this function sets the number of bytes copied to \c{*buflen}. If
|
* the buffer is large enough, this function will insert a null byte after the
|
* last copied byte, to facilitate manipulation of null-terminated strings.
|
* That byte is not included in the returned value of \c{*buflen}.
|
*
|
* The \a next pointer, if not null, will be updated to point to the next item
|
* after this string. If \a value points to the last item, then \a next will be
|
* invalid.
|
*
|
* This function may not run in constant time (it will run in O(n) time on the
|
* number of chunks). It requires constant memory (O(1)).
|
*
|
* \sa cbor_value_dup_text_string(), cbor_value_copy_text_string(), cbor_value_get_string_length(), cbor_value_calculate_string_length()
|
*/
|
|
CborError _cbor_value_copy_string(const CborValue *value, void *buffer,
|
size_t *buflen, CborValue *next)
|
{
|
bool copied_all;
|
CborError err = iterate_string_chunks(value, (char*)buffer, buflen, &copied_all, next,
|
buffer ? (IterateFunction) value->parser->d->cpy : iterate_noop);
|
return err ? err :
|
copied_all ? CborNoError : CborErrorOutOfMemory;
|
}
|
|
/**
|
* Compares the entry \a value with the string \a string and store the result
|
* in \a result. If the value is different from \a string \a result will
|
* contain \c false.
|
*
|
* The entry at \a value may be a tagged string. If \a is not a string or a
|
* tagged string, the comparison result will be false.
|
*
|
* CBOR requires text strings to be encoded in UTF-8, but this function does
|
* not validate either the strings in the stream or the string \a string to be
|
* matched. Moreover, comparison is done on strict codepoint comparison,
|
* without any Unicode normalization.
|
*
|
* This function may not run in constant time (it will run in O(n) time on the
|
* number of chunks). It requires constant memory (O(1)).
|
*
|
* \sa cbor_value_skip_tag(), cbor_value_copy_text_string()
|
*/
|
CborError cbor_value_text_string_equals(const CborValue *value, const char *string, bool *result)
|
{
|
CborValue copy = *value;
|
CborError err = cbor_value_skip_tag(©);
|
if (err)
|
return err;
|
if (!cbor_value_is_text_string(©)) {
|
*result = false;
|
return CborNoError;
|
}
|
|
size_t len = strlen(string);
|
return iterate_string_chunks(©, CONST_CAST(char *, string), &len,
|
result, NULL, value->parser->d->cmp);
|
}
|
|
/**
|
* \fn bool cbor_value_is_array(const CborValue *value)
|
*
|
* Returns true if the iterator \a value is valid and points to a CBOR array.
|
*
|
* \sa cbor_value_is_valid(), cbor_value_is_map()
|
*/
|
|
/**
|
* \fn CborError cbor_value_get_array_length(const CborValue *value, size_t *length)
|
*
|
* Extracts the length of the CBOR array that \a value points to and stores it
|
* in \a result. If the iterator \a value does not point to a CBOR array, the
|
* behaviour is undefined, so checking with \ref cbor_value_get_type or \ref
|
* cbor_value_is_array is recommended.
|
*
|
* If the length of this array is not encoded in the CBOR data stream, this
|
* function will return the recoverable error CborErrorUnknownLength. You may
|
* also check whether that is the case by using cbor_value_is_length_known().
|
*
|
* \note On 32-bit platforms, this function will return error condition of \ref
|
* CborErrorDataTooLarge if the stream indicates a length that is too big to
|
* fit in 32-bit.
|
*
|
* \sa cbor_value_is_valid(), cbor_value_is_length_known()
|
*/
|
|
/**
|
* \fn bool cbor_value_is_map(const CborValue *value)
|
*
|
* Returns true if the iterator \a value is valid and points to a CBOR map.
|
*
|
* \sa cbor_value_is_valid(), cbor_value_is_array()
|
*/
|
|
/**
|
* \fn CborError cbor_value_get_map_length(const CborValue *value, size_t *length)
|
*
|
* Extracts the length of the CBOR map that \a value points to and stores it in
|
* \a result. If the iterator \a value does not point to a CBOR map, the
|
* behaviour is undefined, so checking with \ref cbor_value_get_type or \ref
|
* cbor_value_is_map is recommended.
|
*
|
* If the length of this map is not encoded in the CBOR data stream, this
|
* function will return the recoverable error CborErrorUnknownLength. You may
|
* also check whether that is the case by using cbor_value_is_length_known().
|
*
|
* \note On 32-bit platforms, this function will return error condition of \ref
|
* CborErrorDataTooLarge if the stream indicates a length that is too big to
|
* fit in 32-bit.
|
*
|
* \sa cbor_value_is_valid(), cbor_value_is_length_known()
|
*/
|
|
/**
|
* Attempts to find the value in map \a map that corresponds to the text string
|
* entry \a string. If the iterator \a value does not point to a CBOR map, the
|
* behaviour is undefined, so checking with \ref cbor_value_get_type or \ref
|
* cbor_value_is_map is recommended.
|
*
|
* If the item is found, it is stored in \a result. If no item is found
|
* matching the key, then \a result will contain an element of type \ref
|
* CborInvalidType. Matching is performed using
|
* cbor_value_text_string_equals(), so tagged strings will also match.
|
*
|
* This function has a time complexity of O(n) where n is the number of
|
* elements in the map to be searched. In addition, this function is has O(n)
|
* memory requirement based on the number of nested containers (maps or arrays)
|
* found as elements of this map.
|
*
|
* \sa cbor_value_is_valid(), cbor_value_text_string_equals(), cbor_value_advance()
|
*/
|
CborError cbor_value_map_find_value(const CborValue *map, const char *string, CborValue *element)
|
{
|
assert(cbor_value_is_map(map));
|
size_t len = strlen(string);
|
CborError err = cbor_value_enter_container(map, element);
|
if (err)
|
goto error;
|
|
while (!cbor_value_at_end(element)) {
|
/* find the non-tag so we can compare */
|
err = cbor_value_skip_tag(element);
|
if (err)
|
goto error;
|
if (cbor_value_is_text_string(element)) {
|
bool equals;
|
size_t dummyLen = len;
|
err = iterate_string_chunks(element, CONST_CAST(char *, string), &dummyLen,
|
&equals, element, map->parser->d->cmp);
|
if (err)
|
goto error;
|
if (equals)
|
return preparse_value(element);
|
} else {
|
/* skip this key */
|
err = cbor_value_advance(element);
|
if (err)
|
goto error;
|
}
|
|
/* skip this value */
|
err = cbor_value_skip_tag(element);
|
if (err)
|
goto error;
|
err = cbor_value_advance(element);
|
if (err)
|
goto error;
|
}
|
|
/* not found */
|
element->type = CborInvalidType;
|
return CborNoError;
|
|
error:
|
element->type = CborInvalidType;
|
return err;
|
}
|
|
/**
|
* \fn bool cbor_value_is_float(const CborValue *value)
|
*
|
* Returns true if the iterator \a value is valid and points to a CBOR
|
* single-precision floating point (32-bit).
|
*
|
* \sa cbor_value_is_valid(), cbor_value_is_double(), cbor_value_is_half_float()
|
*/
|
|
/**
|
* \fn CborError cbor_value_get_float(const CborValue *value, float *result)
|
*
|
* Retrieves the CBOR single-precision floating point (32-bit) value that \a
|
* value points to and stores it in \a result. If the iterator \a value does
|
* not point to a single-precision floating point value, the behavior is
|
* undefined, so checking with \ref cbor_value_get_type or with \ref
|
* cbor_value_is_float is recommended.
|
*
|
* \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_float(), cbor_value_get_double()
|
*/
|
|
/**
|
* \fn bool cbor_value_is_double(const CborValue *value)
|
*
|
* Returns true if the iterator \a value is valid and points to a CBOR
|
* double-precision floating point (64-bit).
|
*
|
* \sa cbor_value_is_valid(), cbor_value_is_float(), cbor_value_is_half_float()
|
*/
|
|
/**
|
* \fn CborError cbor_value_get_double(const CborValue *value, float *result)
|
*
|
* Retrieves the CBOR double-precision floating point (64-bit) value that \a
|
* value points to and stores it in \a result. If the iterator \a value does
|
* not point to a double-precision floating point value, the behavior is
|
* undefined, so checking with \ref cbor_value_get_type or with \ref
|
* cbor_value_is_double is recommended.
|
*
|
* \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_double(), cbor_value_get_float()
|
*/
|
|
/**
|
* \fn bool cbor_value_is_half_float(const CborValue *value)
|
*
|
* Returns true if the iterator \a value is valid and points to a CBOR
|
* single-precision floating point (16-bit).
|
*
|
* \sa cbor_value_is_valid(), cbor_value_is_double(), cbor_value_is_float()
|
*/
|
|
/**
|
* Retrieves the CBOR half-precision floating point (16-bit) value that \a
|
* value points to and stores it in \a result. If the iterator \a value does
|
* not point to a half-precision floating point value, the behavior is
|
* undefined, so checking with \ref cbor_value_get_type or with \ref
|
* cbor_value_is_half_float is recommended.
|
*
|
* Note: since the C language does not have a standard type for half-precision
|
* floating point, this function takes a \c{void *} as a parameter for the
|
* storage area, which must be at least 16 bits wide.
|
*
|
* \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_half_float(), cbor_value_get_float()
|
*/
|
CborError cbor_value_get_half_float(const CborValue *value, void *result)
|
{
|
assert(cbor_value_is_half_float(value));
|
|
/* size has been computed already */
|
uint16_t v = value->parser->d->get16(value->parser->d, value->offset + 1);
|
memcpy(result, &v, sizeof(v));
|
return CborNoError;
|
}
|
|
|
/** @} */
|
