+/****************************************************************************
+**
+** Copyright (C) 2017 Intel Corporation
+**
+** Permission is hereby granted, free of charge, to any person obtaining a copy
+** of this software and associated documentation files (the "Software"), to deal
+** in the Software without restriction, including without limitation the rights
+** to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+** copies of the Software, and to permit persons to whom the Software is
+** furnished to do so, subject to the following conditions:
+**
+** The above copyright notice and this permission notice shall be included in
+** all copies or substantial portions of the Software.
+**
+** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+** IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+** FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+** AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+** LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+** OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+** THE SOFTWARE.
+**
+****************************************************************************/
+
+#ifndef _BSD_SOURCE
+#define _BSD_SOURCE 1
+#endif
+#ifndef _DEFAULT_SOURCE
+#define _DEFAULT_SOURCE 1
+#endif
+#ifndef __STDC_LIMIT_MACROS
+# define __STDC_LIMIT_MACROS 1
+#endif
+
+#include "cbor.h"
+#include "cborinternal_p.h"
+#include "compilersupport_p.h"
+
+#include <string.h>
+
+/**
+ * \defgroup CborParsing Parsing CBOR streams
+ * \brief Group of functions used to parse CBOR streams.
+ *
+ * TinyCBOR provides functions for pull-based stream parsing of a CBOR-encoded
+ * payload. The main data type for the parsing is a CborValue, which behaves
+ * like an iterator and can be used to extract the encoded data. It is first
+ * initialized with a call to cbor_parser_init() and is usually used to extract
+ * exactly one item, most often an array or map.
+ *
+ * Nested CborValue objects can be parsed using cbor_value_enter_container().
+ * Each call to cbor_value_enter_container() must be matched by a call to
+ * cbor_value_leave_container(), with the exact same parameters.
+ *
+ * The example below initializes a CborParser object, begins the parsing with a
+ * CborValue and decodes a single integer:
+ *
+ * \code
+ * int extract_int(const uint8_t *buffer, size_t len)
+ * {
+ * CborParser parser;
+ * CborValue value;
+ * int result;
+ * cbor_parser_init(buffer, len, 0, &parser, &value);
+ * cbor_value_get_int(&value, &result);
+ * return result;
+ * }
+ * \endcode
+ *
+ * The code above does no error checking, which means it assumes the data comes
+ * from a source trusted to send one properly-encoded integer. The following
+ * example does the exact same operation, but includes error checking and
+ * returns 0 on parsing failure:
+ *
+ * \code
+ * int extract_int(const uint8_t *buffer, size_t len)
+ * {
+ * CborParser parser;
+ * CborValue value;
+ * int result;
+ * if (cbor_parser_init(buffer, len, 0, &parser, &value) != CborNoError)
+ * return 0;
+ * if (!cbor_value_is_integer(&value) ||
+ * cbor_value_get_int(&value, &result) != CborNoError)
+ * return 0;
+ * return result;
+ * }
+ * \endcode
+ *
+ * Note, in the example above, that one can't distinguish a parsing failure
+ * from an encoded value of zero. Reporting a parsing error is left as an
+ * exercise to the reader.
+ *
+ * The code above does not execute a range-check either: it is possible that
+ * the value decoded from the CBOR stream encodes a number larger than what can
+ * be represented in a variable of type \c{int}. If detecting that case is
+ * important, the code should call cbor_value_get_int_checked() instead.
+ *
+ * <h3 class="groupheader">Memory and parsing constraints</h3>
+ *
+ * TinyCBOR is designed to run with little memory and with minimal overhead.
+ * Except where otherwise noted, the parser functions always run on constant
+ * time (O(1)), do not recurse and never allocate memory (thus, stack usage is
+ * bounded and is O(1)).
+ *
+ * <h3 class="groupheader">Error handling and preconditions</h3>
+ *
+ * All functions operating on a CborValue return a CborError condition, with
+ * CborNoError standing for the normal situation in which no parsing error
+ * occurred. All functions may return parsing errors in case the stream cannot
+ * be decoded properly, be it due to corrupted data or due to reaching the end
+ * of the input buffer.
+ *
+ * Error conditions must not be ignored. All decoder functions have undefined
+ * behavior if called after an error has been reported, and may crash.
+ *
+ * Some functions are also documented to have preconditions, like
+ * cbor_value_get_int() requiring that the input be an integral value.
+ * Violation of preconditions also results in undefined behavior and the
+ * program may crash.
+ */
+
+/**
+ * \addtogroup CborParsing
+ * @{
+ */
+
+/**
+ * \struct CborValue
+ *
+ * This type contains one value parsed from the CBOR stream. Each CborValue
+ * behaves as an iterator in a StAX-style parser.
+ *
+ * \if privatedocs
+ * Implementation details: the CborValue contains these fields:
+ * \list
+ * \li ptr: pointer to the actual data
+ * \li flags: flags from the decoder
+ * \li extra: partially decoded integer value (0, 1 or 2 bytes)
+ * \li remaining: remaining items in this collection after this item or UINT32_MAX if length is unknown
+ * \endlist
+ * \endif
+ */
+
+static inline uint16_t get16(const uint8_t *ptr)
+{
+ uint16_t result;
+ memcpy(&result, ptr, sizeof(result));
+ return cbor_ntohs(result);
+}
+
+static inline uint32_t get32(const uint8_t *ptr)
+{
+ uint32_t result;
+ memcpy(&result, ptr, sizeof(result));
+ return cbor_ntohl(result);
+}
+
+static inline uint64_t get64(const uint8_t *ptr)
+{
+ uint64_t result;
+ memcpy(&result, ptr, sizeof(result));
+ return cbor_ntohll(result);
+}
+
+CborError CBOR_INTERNAL_API_CC _cbor_value_extract_number(const uint8_t **ptr, const uint8_t *end, uint64_t *len)
+{
+ size_t bytesNeeded;
+ uint8_t additional_information = **ptr & SmallValueMask;
+ ++*ptr;
+ if (additional_information < Value8Bit) {
+ *len = additional_information;
+ return CborNoError;
+ }
+ if (unlikely(additional_information > Value64Bit))
+ return CborErrorIllegalNumber;
+
+ bytesNeeded = (size_t)(1 << (additional_information - Value8Bit));
+ if (unlikely(bytesNeeded > (size_t)(end - *ptr))) {
+ return CborErrorUnexpectedEOF;
+ } else if (bytesNeeded == 1) {
+ *len = (uint8_t)(*ptr)[0];
+ } else if (bytesNeeded == 2) {
+ *len = get16(*ptr);
+ } else if (bytesNeeded == 4) {
+ *len = get32(*ptr);
+ } else {
+ *len = get64(*ptr);
+ }
+ *ptr += bytesNeeded;
+ return CborNoError;
+}
+
+static CborError extract_length(const CborParser *parser, const uint8_t **ptr, size_t *len)
+{
+ uint64_t v;
+ CborError err = _cbor_value_extract_number(ptr, parser->end, &v);
+ if (err) {
+ *len = 0;
+ return err;
+ }
+
+ *len = (size_t)v;
+ if (v != *len)
+ return CborErrorDataTooLarge;
+ return CborNoError;
+}
+
+static bool is_fixed_type(uint8_t type)
+{
+ return type != CborTextStringType && type != CborByteStringType && type != CborArrayType &&
+ type != CborMapType;
+}
+
+static CborError preparse_value(CborValue *it)
+{
+ const CborParser *parser = it->parser;
+ it->type = CborInvalidType;
+
+ /* are we at the end? */
+ if (it->ptr == parser->end)
+ return CborErrorUnexpectedEOF;
+
+ uint8_t descriptor = *it->ptr;
+ uint8_t type = descriptor & MajorTypeMask;
+ it->type = type;
+ it->flags = 0;
+ 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->ptr))
+ return CborErrorUnexpectedEOF;
+
+ uint8_t majortype = type >> MajorTypeShift;
+ if (majortype == NegativeIntegerType) {
+ it->flags |= CborIteratorFlag_NegativeInteger;
+ it->type = CborIntegerType;
+ } else if (majortype == SimpleTypesType) {
+ switch (descriptor) {
+ case FalseValue:
+ it->extra = false;
+ it->type = CborBooleanType;
+ break;
+
+ case SinglePrecisionFloat:
+ case DoublePrecisionFloat:
+ it->flags |= CborIteratorFlag_IntegerValueTooLarge;
+ /* fall through */
+ case TrueValue:
+ case NullValue:
+ case UndefinedValue:
+ case HalfPrecisionFloat:
+ it->type = *it->ptr;
+ break;
+
+ case SimpleTypeInNextByte:
+ it->extra = (uint8_t)it->ptr[1];
+#ifndef CBOR_PARSER_NO_STRICT_CHECKS
+ if (unlikely(it->extra < 32)) {
+ it->type = CborInvalidType;
+ return CborErrorIllegalSimpleType;
+ }
+#endif
+ break;
+
+ case 28:
+ case 29:
+ case 30:
+ case Break:
+ cbor_assert(false); /* these conditions can't be reached */
+ return CborErrorUnexpectedBreak;
+ }
+ return CborNoError;
+ }
+
+ /* try to decode up to 16 bits */
+ if (descriptor < Value8Bit)
+ return CborNoError;
+
+ if (descriptor == Value8Bit)
+ it->extra = (uint8_t)it->ptr[1];
+ else if (descriptor == Value16Bit)
+ it->extra = get16(it->ptr + 1);
+ else
+ it->flags |= CborIteratorFlag_IntegerValueTooLarge; /* Value32Bit or Value64Bit */
+ return CborNoError;
+}
+
+static CborError preparse_next_value_nodecrement(CborValue *it)
+{
+ if (it->remaining == UINT32_MAX && it->ptr != it->parser->end && *it->ptr == (uint8_t)BreakByte) {
+ /* end of map or array */
+ ++it->ptr;
+ it->type = CborInvalidType;
+ it->remaining = 0;
+ return CborNoError;
+ }
+
+ return preparse_value(it);
+}
+
+static CborError preparse_next_value(CborValue *it)
+{
+ if (it->remaining != UINT32_MAX) {
+ /* don't decrement the item count if the current item is tag: they don't count */
+ if (it->type != CborTagType && --it->remaining == 0) {
+ it->type = CborInvalidType;
+ return CborNoError;
+ }
+ }
+ return preparse_next_value_nodecrement(it);
+}
+
+static CborError advance_internal(CborValue *it)
+{
+ uint64_t length;
+ CborError err = _cbor_value_extract_number(&it->ptr, it->parser->end, &length);
+ cbor_assert(err == CborNoError);
+
+ if (it->type == CborByteStringType || it->type == CborTextStringType) {
+ cbor_assert(length == (size_t)length);
+ cbor_assert((it->flags & CborIteratorFlag_UnknownLength) == 0);
+ it->ptr += length;
+ }
+
+ return preparse_next_value(it);
+}
+
+/** \internal
+ *
+ * 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.
+ *
+ * This function is also used to extract single- and double-precision floating
+ * point values (SinglePrecisionFloat == Value32Bit and DoublePrecisionFloat ==
+ * Value64Bit).
+ */
+uint64_t _cbor_value_decode_int64_internal(const CborValue *value)
+{
+ cbor_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 */
+ cbor_assert((*value->ptr & SmallValueMask) == Value32Bit || (*value->ptr & SmallValueMask) == Value64Bit);
+ if ((*value->ptr & 1) == (Value32Bit & 1))
+ return get32(value->ptr + 1);
+
+ cbor_assert((*value->ptr & SmallValueMask) == Value64Bit);
+ return get64(value->ptr + 1);
+}
+
+/**
+ * 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(const uint8_t *buffer, size_t size, uint32_t flags, CborParser *parser, CborValue *it)
+{
+ memset(parser, 0, sizeof(*parser));
+ parser->end = buffer + size;
+ parser->flags = flags;
+ it->parser = parser;
+ it->ptr = buffer;
+ 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_value_at_end(), cbor_value_get_type()
+ */
+
+/**
+ * Performs a basic validation of the CBOR stream pointed by \a it and returns
+ * the error it found. If no error was found, it returns CborNoError and the
+ * application can iterate over the items with certainty that no other errors
+ * will appear during parsing.
+ *
+ * A basic validation checks for:
+ * \list
+ * \li absence of undefined additional information bytes;
+ * \li well-formedness of all numbers, lengths, and simple values;
+ * \li string contents match reported sizes;
+ * \li arrays and maps contain the number of elements they are reported to have;
+ * \endlist
+ *
+ * For further checks, see cbor_value_validate().
+ *
+ * This function has the same timing and memory requirements as
+ * cbor_value_advance().
+ *
+ * \sa cbor_value_validate(), cbor_value_advance()
+ */
+CborError cbor_value_validate_basic(const CborValue *it)
+{
+ CborValue value = *it;
+ return cbor_value_advance(&value);
+}
+
+/**
+ * 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 it 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)
+{
+ cbor_assert(it->type != CborInvalidType);
+ cbor_assert(is_fixed_type(it->type));
+ if (!it->remaining)
+ return CborErrorAdvancePastEOF;
+ return advance_internal(it);
+}
+
+static CborError advance_recursive(CborValue *it, int nestingLevel)
+{
+ CborError err;
+ CborValue recursed;
+
+ 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 == 0)
+ return CborErrorNestingTooDeep;
+
+ 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).
+ *
+ * The number of recursions can be limited at compile time to avoid stack
+ * exhaustion in constrained systems.
+ *
+ * \sa cbor_value_at_end(), cbor_value_advance_fixed(), cbor_value_enter_container(), cbor_value_leave_container()
+ */
+CborError cbor_value_advance(CborValue *it)
+{
+ cbor_assert(it->type != CborInvalidType);
+ if (!it->remaining)
+ return CborErrorAdvancePastEOF;
+ return advance_recursive(it, CBOR_PARSER_MAX_RECURSIONS);
+}
+
+/**
+ * \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)
+{
+ cbor_assert(cbor_value_is_container(it));
+ *recursed = *it;
+
+ if (it->flags & CborIteratorFlag_UnknownLength) {
+ recursed->remaining = UINT32_MAX;
+ ++recursed->ptr;
+ } else {
+ uint64_t len;
+ CborError err = _cbor_value_extract_number(&recursed->ptr, recursed->parser->end, &len);
+ cbor_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->ptr = it->ptr;
+ 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->ptr = it->ptr;
+ return CborErrorDataTooLarge;
+ }
+ recursed->remaining *= 2;
+ }
+ if (len == 0) {
+ /* the case of the empty container */
+ recursed->type = CborInvalidType;
+ return CborNoError;
+ }
+ }
+ return preparse_next_value_nodecrement(recursed);
+}
+
+/**
+ * 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)
+{
+ cbor_assert(cbor_value_is_container(it));
+ cbor_assert(recursed->type == CborInvalidType);
+ it->ptr = recursed->ptr;
+ 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() if 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 \ref 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)
+{
+ uint64_t v;
+ cbor_assert(cbor_value_is_integer(value));
+ 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 \ref 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)
+{
+ uint64_t v;
+ cbor_assert(cbor_value_is_integer(value));
+ 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 to use
+ * two's complement representation (although int32_t is).
+ */
+
+ if (value->flags & CborIteratorFlag_NegativeInteger) {
+ if (unlikely(v > (unsigned) -(INT_MIN + 1)))
+ return CborErrorDataTooLarge;
+
+ *result = (int)v;
+ *result = -*result - 1;
+ } else {
+ if (unlikely(v > (uint64_t)INT_MAX))
+ return CborErrorDataTooLarge;
+
+ *result = (int)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_text_string(), cbor_value_copy_byte_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);
+}
+
+static inline void prepare_string_iteration(CborValue *it)
+{
+ if (!cbor_value_is_length_known(it)) {
+ /* chunked string: we're before the first chunk;
+ * advance to the first chunk */
+ ++it->ptr;
+ it->flags |= CborIteratorFlag_IteratingStringChunks;
+ }
+}
+
+CborError CBOR_INTERNAL_API_CC _cbor_value_prepare_string_iteration(CborValue *it)
+{
+ cbor_assert((it->flags & CborIteratorFlag_IteratingStringChunks) == 0);
+ prepare_string_iteration(it);
+
+ /* are we at the end? */
+ if (it->ptr == it->parser->end)
+ return CborErrorUnexpectedEOF;
+ return CborNoError;
+}
+
+static CborError get_string_chunk(CborValue *it, const void **bufferptr, size_t *len)
+{
+ CborError err;
+
+ /* Possible states:
+ * length known | iterating | meaning
+ * no | no | before the first chunk of a chunked string
+ * yes | no | at a non-chunked string
+ * no | yes | second or later chunk
+ * yes | yes | after a non-chunked string
+ */
+ if (it->flags & CborIteratorFlag_IteratingStringChunks) {
+ /* already iterating */
+ if (cbor_value_is_length_known(it)) {
+ /* if the length was known, it wasn't chunked, so finish iteration */
+ goto last_chunk;
+ }
+ } else {
+ prepare_string_iteration(it);
+ }
+
+ /* are we at the end? */
+ if (it->ptr == it->parser->end)
+ return CborErrorUnexpectedEOF;
+
+ if (*it->ptr == BreakByte) {
+ /* last chunk */
+ ++it->ptr;
+last_chunk:
+ *bufferptr = NULL;
+ *len = 0;
+ return preparse_next_value(it);
+ } else if ((uint8_t)(*it->ptr & MajorTypeMask) == it->type) {
+ err = extract_length(it->parser, &it->ptr, len);
+ if (err)
+ return err;
+ if (*len > (size_t)(it->parser->end - it->ptr))
+ return CborErrorUnexpectedEOF;
+
+ *bufferptr = it->ptr;
+ it->ptr += *len;
+ } else {
+ return CborErrorIllegalType;
+ }
+
+ it->flags |= CborIteratorFlag_IteratingStringChunks;
+ return CborNoError;
+}
+
+CborError CBOR_INTERNAL_API_CC
+_cbor_value_get_string_chunk(const CborValue *value, const void **bufferptr,
+ size_t *len, CborValue *next)
+{
+ CborValue tmp;
+ if (!next)
+ next = &tmp;
+ *next = *value;
+ return get_string_chunk(next, bufferptr, len);
+}
+
+/* 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)(char *, const uint8_t *, size_t);
+
+static uintptr_t iterate_noop(char *dest, const uint8_t *src, size_t len)
+{
+ (void)dest;
+ (void)src;
+ (void)len;
+ return true;
+}
+
+static uintptr_t iterate_memcmp(char *s1, const uint8_t *s2, size_t len)
+{
+ return memcmp(s1, (const char *)s2, len) == 0;
+}
+
+static uintptr_t iterate_memcpy(char *dest, const uint8_t *src, size_t len)
+{
+ return (uintptr_t)memcpy(dest, src, len);
+}
+
+static CborError iterate_string_chunks(const CborValue *value, char *buffer, size_t *buflen,
+ bool *result, CborValue *next, IterateFunction func)
+{
+ CborError err;
+ CborValue tmp;
+ size_t total = 0;
+ const void *ptr;
+
+ cbor_assert(cbor_value_is_byte_string(value) || cbor_value_is_text_string(value));
+ if (!next)
+ next = &tmp;
+ *next = *value;
+ *result = true;
+
+ while (1) {
+ size_t newTotal;
+ size_t chunkLen;
+ err = get_string_chunk(next, &ptr, &chunkLen);
+ if (err)
+ return err;
+ if (!ptr)
+ break;
+
+ if (unlikely(add_check_overflow(total, chunkLen, &newTotal)))
+ return CborErrorDataTooLarge;
+
+ if (*result && *buflen >= newTotal)
+ *result = !!func(buffer + total, (const uint8_t *)ptr, chunkLen);
+ else
+ *result = false;
+
+ total = newTotal;
+ }
+
+ /* is there enough room for the ending NUL byte? */
+ if (*result && *buflen > total) {
+ uint8_t nul[] = { 0 };
+ *result = !!func(buffer + total, nul, 1);
+ }
+ *buflen = total;
+ return CborNoError;
+}
+
+/**
+ * \fn CborError cbor_value_copy_text_string(const CborValue *value, char *buffer, size_t *buflen, CborValue *next)
+ *
+ * Copies the string pointed to 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}. If there was no space for
+ * the terminating null, no error is returned, so callers must check the value
+ * of *buflen after the call, before relying on the '\0'; if it has not been
+ * changed by the call, there is no '\0'-termination on the buffer's contents.
+ *
+ * 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_get_text_string_chunk() 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_get_byte_string_chunk(), 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 ? iterate_memcpy : iterate_noop);
+ return err ? err :
+ copied_all ? CborNoError : CborErrorOutOfMemory;
+}
+
+/**
+ * Compares the entry \a value with the string \a string and stores 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 value 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)
+{
+ size_t len;
+ CborValue copy = *value;
+ CborError err = cbor_value_skip_tag(©);
+ if (err)
+ return err;
+ if (!cbor_value_is_text_string(©)) {
+ *result = false;
+ return CborNoError;
+ }
+
+ len = strlen(string);
+ return iterate_string_chunks(©, CONST_CAST(char *, string), &len, result, NULL, iterate_memcmp);
+}
+
+/**
+ * \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)
+{
+ CborError err;
+ size_t len = strlen(string);
+ cbor_assert(cbor_value_is_map(map));
+ 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, iterate_memcmp);
+ 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)
+{
+ uint16_t v;
+ cbor_assert(cbor_value_is_half_float(value));
+
+ /* size has been computed already */
+ v = get16(value->ptr + 1);
+ memcpy(result, &v, sizeof(v));
+ return CborNoError;
+}
+
+/** @} */