cbor.h

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/****************************************************************************
**
** Copyright (C) 2015 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 CBOR_H
#define CBOR_H

#include <assert.h>
#include <limits.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include <stdio.h>

#include "tinycbor-version.h"

#define TINYCBOR_VERSION            ((TINYCBOR_VERSION_MAJOR << 16) | (TINYCBOR_VERSION_MINOR << 8) | TINYCBOR_VERSION_PATCH)

#ifdef __cplusplus
extern "C" {
#else
#include <stdbool.h>
#endif

#ifndef SIZE_MAX
/* Some systems fail to define SIZE_MAX in <stdint.h>, even though C99 requires it...
 * Conversion from signed to unsigned is defined in 6.3.1.3 (Signed and unsigned integers) p2,
 * which says: "the value is converted by repeatedly adding or subtracting one more than the
 * maximum value that can be represented in the new type until the value is in the range of the
 * new type."
 * So -1 gets converted to size_t by adding SIZE_MAX + 1, which results in SIZE_MAX.
 */
#  define SIZE_MAX ((size_t)-1)
#endif

#ifndef CBOR_API
#  define CBOR_API
#endif
#ifndef CBOR_PRIVATE_API
#  define CBOR_PRIVATE_API
#endif
#ifndef CBOR_INLINE_API
#  if defined(__cplusplus)
#    define CBOR_INLINE inline
#    define CBOR_INLINE_API inline
#  else
#    define CBOR_INLINE_API static CBOR_INLINE
#    if defined(_MSC_VER)
#      define CBOR_INLINE __inline
#    elif defined(__GNUC__)
#      define CBOR_INLINE __inline__
#    elif defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
#      define CBOR_INLINE inline
#    else
#      define CBOR_INLINE
#    endif
#  endif
#endif

typedef enum CborType {
    CborIntegerType     = 0x00,
    CborByteStringType  = 0x40,
    CborTextStringType  = 0x60,
    CborArrayType       = 0x80,
    CborMapType         = 0xa0,
    CborTagType         = 0xc0,
    CborSimpleType      = 0xe0,
    CborBooleanType     = 0xf5,
    CborNullType        = 0xf6,
    CborUndefinedType   = 0xf7,
    CborHalfFloatType   = 0xf9,
    CborFloatType       = 0xfa,
    CborDoubleType      = 0xfb,

    CborInvalidType     = 0xff              /* equivalent to the break byte, so it will never be used */
} CborType;

typedef uint64_t CborTag;
typedef enum CborKnownTags {
    CborDateTimeStringTag          = 0,        /* RFC 3339 format: YYYY-MM-DD hh:mm:ss+zzzz */
    CborUnixTime_tTag              = 1,
    CborPositiveBignumTag          = 2,
    CborNegativeBignumTag          = 3,
    CborDecimalTag                 = 4,
    CborBigfloatTag                = 5,
    CborExpectedBase64urlTag       = 21,
    CborExpectedBase64Tag          = 22,
    CborExpectedBase16Tag          = 23,
    CborUriTag                     = 32,
    CborBase64urlTag               = 33,
    CborBase64Tag                  = 34,
    CborRegularExpressionTag       = 35,
    CborMimeMessageTag             = 36,       /* RFC 2045-2047 */
    CborSignatureTag               = 55799
} CborKnownTags;

/* Error API */

typedef enum CborError {
    CborNoError = 0,

    /* errors in all modes */
    CborUnknownError,
    CborErrorUnknownLength,         /* request for length in array, map, or string with indeterminate length */
    CborErrorAdvancePastEOF,
    CborErrorIO,

    /* parser errors streaming errors */
    CborErrorGarbageAtEnd = 256,
    CborErrorUnexpectedEOF,
    CborErrorUnexpectedBreak,
    CborErrorUnknownType,           /* can only heppen in major type 7 */
    CborErrorIllegalType,           /* type not allowed here */
    CborErrorIllegalNumber,
    CborErrorIllegalSimpleType,     /* types of value less than 32 encoded in two bytes */

    /* parser errors in strict mode parsing only */
    CborErrorUnknownSimpleType = 512,
    CborErrorUnknownTag,
    CborErrorInappropriateTagForType,
    CborErrorDuplicateObjectKeys,
    CborErrorInvalidUtf8TextString,

    /* encoder errors */
    CborErrorTooManyItems = 768,
    CborErrorTooFewItems,

    /* internal implementation errors */
    CborErrorDataTooLarge = 1024,
    CborErrorNestingTooDeep,
    CborErrorUnsupportedType,

    /* errors in converting to JSON */
    CborErrorJsonObjectKeyIsAggregate,
    CborErrorJsonObjectKeyNotString,
    CborErrorJsonNotImplemented,

    CborErrorOutOfMemory = ~0U / 2 + 1,
    CborErrorInternalError = ~0U
} CborError;

CBOR_API const char *cbor_error_string(CborError error);

/* Encoder API */
struct CborEncoder
{
    union {
        uint8_t *ptr;
        ptrdiff_t bytes_needed;
    } data;
    const uint8_t *end;
    size_t added;
    int flags;
};
typedef struct CborEncoder CborEncoder;

static const size_t CborIndefiniteLength = SIZE_MAX;

CBOR_API void cbor_encoder_init(CborEncoder *encoder, uint8_t *buffer, size_t size, int flags);
CBOR_API CborError cbor_encode_uint(CborEncoder *encoder, uint64_t value);
CBOR_API CborError cbor_encode_int(CborEncoder *encoder, int64_t value);
CBOR_API CborError cbor_encode_negative_int(CborEncoder *encoder, uint64_t absolute_value);
CBOR_API CborError cbor_encode_simple_value(CborEncoder *encoder, uint8_t value);
CBOR_API CborError cbor_encode_tag(CborEncoder *encoder, CborTag tag);
CBOR_API CborError cbor_encode_text_string(CborEncoder *encoder, const char *string, size_t length);
CBOR_INLINE_API CborError cbor_encode_text_stringz(CborEncoder *encoder, const char *string)
{ return cbor_encode_text_string(encoder, string, strlen(string)); }
CBOR_API CborError cbor_encode_byte_string(CborEncoder *encoder, const uint8_t *string, size_t length);
CBOR_API CborError cbor_encode_floating_point(CborEncoder *encoder, CborType fpType, const void *value);

CBOR_INLINE_API CborError cbor_encode_boolean(CborEncoder *encoder, bool value)
{ return cbor_encode_simple_value(encoder, (int)value - 1 + (CborBooleanType & 0x1f)); }
CBOR_INLINE_API CborError cbor_encode_null(CborEncoder *encoder)
{ return cbor_encode_simple_value(encoder, CborNullType & 0x1f); }
CBOR_INLINE_API CborError cbor_encode_undefined(CborEncoder *encoder)
{ return cbor_encode_simple_value(encoder, CborUndefinedType & 0x1f); }

CBOR_INLINE_API CborError cbor_encode_half_float(CborEncoder *encoder, const void *value)
{ return cbor_encode_floating_point(encoder, CborHalfFloatType, value); }
CBOR_INLINE_API CborError cbor_encode_float(CborEncoder *encoder, float value)
{ return cbor_encode_floating_point(encoder, CborFloatType, &value); }
CBOR_INLINE_API CborError cbor_encode_double(CborEncoder *encoder, double value)
{ return cbor_encode_floating_point(encoder, CborDoubleType, &value); }

CBOR_API CborError cbor_encoder_create_array(CborEncoder *encoder, CborEncoder *arrayEncoder, size_t length);
CBOR_API CborError cbor_encoder_create_map(CborEncoder *encoder, CborEncoder *mapEncoder, size_t length);
CBOR_API CborError cbor_encoder_close_container(CborEncoder *encoder, const CborEncoder *containerEncoder);
CBOR_API CborError cbor_encoder_close_container_checked(CborEncoder *encoder, const CborEncoder *containerEncoder);

CBOR_INLINE_API size_t cbor_encoder_get_buffer_size(const CborEncoder *encoder, const uint8_t *buffer)
{
    return (size_t)(encoder->data.ptr - buffer);
}

CBOR_INLINE_API size_t cbor_encoder_get_extra_bytes_needed(const CborEncoder *encoder)
{
    return encoder->end ? 0 : (size_t)encoder->data.bytes_needed;
}

/* Parser API */

enum CborParserIteratorFlags
{
    CborIteratorFlag_IntegerValueTooLarge   = 0x01,
    CborIteratorFlag_NegativeInteger        = 0x02,
    CborIteratorFlag_UnknownLength          = 0x04,
    CborIteratorFlag_ContainerIsMap         = 0x20
};

struct CborParser
{
    const uint8_t *end;
    int flags;
};
typedef struct CborParser CborParser;

struct CborValue
{
    const CborParser *parser;
    const uint8_t *ptr;
    uint32_t remaining;
    uint16_t extra;
    uint8_t type;
    uint8_t flags;
};
typedef struct CborValue CborValue;

CBOR_API CborError cbor_parser_init(const uint8_t *buffer, size_t size, int flags, CborParser *parser, CborValue *it);

CBOR_INLINE_API bool cbor_value_at_end(const CborValue *it)
{ return it->remaining == 0; }
CBOR_INLINE_API const uint8_t *cbor_value_get_next_byte(const CborValue *it)
{ return it->ptr; }
CBOR_API CborError cbor_value_advance_fixed(CborValue *it);
CBOR_API CborError cbor_value_advance(CborValue *it);
CBOR_INLINE_API bool cbor_value_is_container(const CborValue *it)
{ return it->type == CborArrayType || it->type == CborMapType; }
CBOR_API CborError cbor_value_enter_container(const CborValue *it, CborValue *recursed);
CBOR_API CborError cbor_value_leave_container(CborValue *it, const CborValue *recursed);

CBOR_PRIVATE_API uint64_t _cbor_value_decode_int64_internal(const CborValue *value);
CBOR_INLINE_API uint64_t _cbor_value_extract_int64_helper(const CborValue *value)
{
    return value->flags & CborIteratorFlag_IntegerValueTooLarge ?
                _cbor_value_decode_int64_internal(value) : value->extra;
}

CBOR_INLINE_API bool cbor_value_is_valid(const CborValue *value)
{ return value && value->type != CborInvalidType; }
CBOR_INLINE_API CborType cbor_value_get_type(const CborValue *value)
{ return (CborType)value->type; }

/* Null & undefined type */
CBOR_INLINE_API bool cbor_value_is_null(const CborValue *value)
{ return value->type == CborNullType; }
CBOR_INLINE_API bool cbor_value_is_undefined(const CborValue *value)
{ return value->type == CborUndefinedType; }

/* Booleans */
CBOR_INLINE_API bool cbor_value_is_boolean(const CborValue *value)
{ return value->type == CborBooleanType; }
CBOR_INLINE_API CborError cbor_value_get_boolean(const CborValue *value, bool *result)
{
    assert(cbor_value_is_boolean(value));
    *result = !!value->extra;
    return CborNoError;
}

/* Simple types */
CBOR_INLINE_API bool cbor_value_is_simple_type(const CborValue *value)
{ return value->type == CborSimpleType; }
CBOR_INLINE_API CborError cbor_value_get_simple_type(const CborValue *value, uint8_t *result)
{
    assert(cbor_value_is_simple_type(value));
    *result = (uint8_t)value->extra;
    return CborNoError;
}

/* Integers */
CBOR_INLINE_API bool cbor_value_is_integer(const CborValue *value)
{ return value->type == CborIntegerType; }
CBOR_INLINE_API bool cbor_value_is_unsigned_integer(const CborValue *value)
{ return cbor_value_is_integer(value) && (value->flags & CborIteratorFlag_NegativeInteger) == 0; }
CBOR_INLINE_API bool cbor_value_is_negative_integer(const CborValue *value)
{ return cbor_value_is_integer(value) && (value->flags & CborIteratorFlag_NegativeInteger); }

CBOR_INLINE_API CborError cbor_value_get_raw_integer(const CborValue *value, uint64_t *result)
{
    assert(cbor_value_is_integer(value));
    *result = _cbor_value_extract_int64_helper(value);
    return CborNoError;
}

CBOR_INLINE_API CborError cbor_value_get_uint64(const CborValue *value, uint64_t *result)
{
    assert(cbor_value_is_unsigned_integer(value));
    *result = _cbor_value_extract_int64_helper(value);
    return CborNoError;
}

CBOR_INLINE_API CborError cbor_value_get_int64(const CborValue *value, int64_t *result)
{
    assert(cbor_value_is_integer(value));
    *result = (int64_t) _cbor_value_extract_int64_helper(value);
    if (value->flags & CborIteratorFlag_NegativeInteger)
        *result = -*result - 1;
    return CborNoError;
}

CBOR_INLINE_API CborError cbor_value_get_int(const CborValue *value, int *result)
{
    assert(cbor_value_is_integer(value));
    *result = (int) _cbor_value_extract_int64_helper(value);
    if (value->flags & CborIteratorFlag_NegativeInteger)
        *result = -*result - 1;
    return CborNoError;
}

CBOR_API CborError cbor_value_get_int64_checked(const CborValue *value, int64_t *result);
CBOR_API CborError cbor_value_get_int_checked(const CborValue *value, int *result);

CBOR_INLINE_API bool cbor_value_is_length_known(const CborValue *value)
{ return (value->flags & CborIteratorFlag_UnknownLength) == 0; }

/* Tags */
CBOR_INLINE_API bool cbor_value_is_tag(const CborValue *value)
{ return value->type == CborTagType; }
CBOR_INLINE_API CborError cbor_value_get_tag(const CborValue *value, CborTag *result)
{
    assert(cbor_value_is_tag(value));
    *result = _cbor_value_extract_int64_helper(value);
    return CborNoError;
}
CBOR_API CborError cbor_value_skip_tag(CborValue *it);

/* Strings */
CBOR_INLINE_API bool cbor_value_is_byte_string(const CborValue *value)
{ return value->type == CborByteStringType; }
CBOR_INLINE_API bool cbor_value_is_text_string(const CborValue *value)
{ return value->type == CborTextStringType; }

CBOR_INLINE_API CborError cbor_value_get_string_length(const CborValue *value, size_t *length)
{
    assert(cbor_value_is_byte_string(value) || cbor_value_is_text_string(value));
    if (!cbor_value_is_length_known(value))
        return CborErrorUnknownLength;
    uint64_t v = _cbor_value_extract_int64_helper(value);
    *length = (size_t)v;
    if (*length != v)
        return CborErrorDataTooLarge;
    return CborNoError;
}

CBOR_PRIVATE_API CborError _cbor_value_copy_string(const CborValue *value, void *buffer,
                                                   size_t *buflen, CborValue *next);
CBOR_PRIVATE_API CborError _cbor_value_dup_string(const CborValue *value, void **buffer,
                                                  size_t *buflen, CborValue *next);

CBOR_API CborError cbor_value_calculate_string_length(const CborValue *value, size_t *length);

CBOR_INLINE_API CborError cbor_value_copy_text_string(const CborValue *value, char *buffer,
                                                      size_t *buflen, CborValue *next)
{
    assert(cbor_value_is_text_string(value));
    return _cbor_value_copy_string(value, buffer, buflen, next);
}
CBOR_INLINE_API CborError cbor_value_copy_byte_string(const CborValue *value, uint8_t *buffer,
                                                      size_t *buflen, CborValue *next)
{
    assert(cbor_value_is_byte_string(value));
    return _cbor_value_copy_string(value, buffer, buflen, next);
}

CBOR_INLINE_API CborError cbor_value_dup_text_string(const CborValue *value, char **buffer,
                                                     size_t *buflen, CborValue *next)
{
    assert(cbor_value_is_text_string(value));
    return _cbor_value_dup_string(value, (void **)buffer, buflen, next);
}
CBOR_INLINE_API CborError cbor_value_dup_byte_string(const CborValue *value, uint8_t **buffer,
                                                     size_t *buflen, CborValue *next)
{
    assert(cbor_value_is_byte_string(value));
    return _cbor_value_dup_string(value, (void **)buffer, buflen, next);
}

/* ### TBD: partial reading API */

CBOR_API CborError cbor_value_text_string_equals(const CborValue *value, const char *string, bool *result);

/* Maps and arrays */
CBOR_INLINE_API bool cbor_value_is_array(const CborValue *value)
{ return value->type == CborArrayType; }
CBOR_INLINE_API bool cbor_value_is_map(const CborValue *value)
{ return value->type == CborMapType; }

CBOR_INLINE_API CborError cbor_value_get_array_length(const CborValue *value, size_t *length)
{
    assert(cbor_value_is_array(value));
    if (!cbor_value_is_length_known(value))
        return CborErrorUnknownLength;
    uint64_t v = _cbor_value_extract_int64_helper(value);
    *length = (size_t)v;
    if (*length != v)
        return CborErrorDataTooLarge;
    return CborNoError;
}

CBOR_INLINE_API CborError cbor_value_get_map_length(const CborValue *value, size_t *length)
{
    assert(cbor_value_is_map(value));
    if (!cbor_value_is_length_known(value))
        return CborErrorUnknownLength;
    uint64_t v = _cbor_value_extract_int64_helper(value);
    *length = (size_t)v;
    if (*length != v)
        return CborErrorDataTooLarge;
    return CborNoError;
}

CBOR_API CborError cbor_value_map_find_value(const CborValue *map, const char *string, CborValue *element);

/* Floating point */
CBOR_INLINE_API bool cbor_value_is_half_float(const CborValue *value)
{ return value->type == CborHalfFloatType; }
CBOR_API CborError cbor_value_get_half_float(const CborValue *value, void *result);

CBOR_INLINE_API bool cbor_value_is_float(const CborValue *value)
{ return value->type == CborFloatType; }
CBOR_INLINE_API CborError cbor_value_get_float(const CborValue *value, float *result)
{
    assert(cbor_value_is_float(value));
    assert(value->flags & CborIteratorFlag_IntegerValueTooLarge);
    uint32_t data = (uint32_t)_cbor_value_decode_int64_internal(value);
    memcpy(result, &data, sizeof(*result));
    return CborNoError;
}

CBOR_INLINE_API bool cbor_value_is_double(const CborValue *value)
{ return value->type == CborDoubleType; }
CBOR_INLINE_API CborError cbor_value_get_double(const CborValue *value, double *result)
{
    assert(cbor_value_is_double(value));
    assert(value->flags & CborIteratorFlag_IntegerValueTooLarge);
    uint64_t data = _cbor_value_decode_int64_internal(value);
    memcpy(result, &data, sizeof(*result));
    return CborNoError;
}

/* Human-readable (dump) API */
CBOR_API CborError cbor_value_to_pretty_advance(FILE *out, CborValue *value);
CBOR_INLINE_API CborError cbor_value_to_pretty(FILE *out, const CborValue *value)
{
    CborValue copy = *value;
    return cbor_value_to_pretty_advance(out, &copy);
}

#ifdef __cplusplus
}
#endif

#endif /* CBOR_H */