src/qcbor_decode.c

/*==============================================================================
 Copyright (c) 2016-2018, The Linux Foundation.
 Copyright (c) 2018-2020, Laurence Lundblade.
 All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above
      copyright notice, this list of conditions and the following
      disclaimer in the documentation and/or other materials provided
      with the distribution.
    * Neither the name of The Linux Foundation nor the names of its
      contributors, nor the name "Laurence Lundblade" may be used to
      endorse or promote products derived from this software without
      specific prior written permission.

THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 =============================================================================*/


#include "qcbor/qcbor_decode.h"
#include "qcbor/qcbor_spiffy_decode.h"
#include "ieee754.h" // Does not use math.h

#ifndef QCBOR_DISABLE_FLOAT_HW_USE
#include <math.h> // For isnan(), llround(), llroudf(), round(), roundf(),
                  // pow(), exp2()
#include <fenv.h> // feclearexcept(), fetestexcept()
#endif


/*
 This casts away the const-ness of a pointer, usually so it can be
 freed or realloced.
 */
#define UNCONST_POINTER(ptr)    ((void *)(ptr))

#define SIZEOF_C_ARRAY(array,type) (sizeof(array)/sizeof(type))


inline static bool
// TODO: add more tests for QCBOR_TYPE_MAP_AS_ARRAY mode in qcbor_decode_tests.c
QCBORItem_IsMapOrArray(const QCBORItem *pMe)
{
   const uint8_t uDataType = pMe->uDataType;
   return uDataType == QCBOR_TYPE_MAP ||
          uDataType == QCBOR_TYPE_ARRAY ||
          uDataType == QCBOR_TYPE_MAP_AS_ARRAY;
}

inline static bool
QCBORItem_IsEmptyDefiniteLengthMapOrArray(const QCBORItem *pMe)
{
   if(!QCBORItem_IsMapOrArray(pMe)){
      return false;
   }

   if(pMe->val.uCount != 0) {
      return false;
   }
   return true;
}

inline static bool
QCBORItem_IsIndefiniteLengthMapOrArray(const QCBORItem *pMe)
{
   if(!QCBORItem_IsMapOrArray(pMe)){
      return false;
   }

   if(pMe->val.uCount != QCBOR_COUNT_INDICATES_INDEFINITE_LENGTH) {
      return false;
   }
   return true;
}


/*===========================================================================
   DecodeNesting -- Tracking array/map/sequence/bstr-wrapped nesting
  ===========================================================================*/

/*
 See commecnts about and typedef of QCBORDecodeNesting in qcbor_private.h,
 the data structure all these functions work on.
 */


inline static uint8_t
DecodeNesting_GetCurrentLevel(const QCBORDecodeNesting *pNesting)
{
   const ptrdiff_t nLevel = pNesting->pCurrent - &(pNesting->pLevels[0]);
   /*
    Limit in DecodeNesting_Descend against more than
    QCBOR_MAX_ARRAY_NESTING gaurantees cast is safe
    */
   return (uint8_t)nLevel;
}


inline static uint8_t
DecodeNesting_GetBoundedModeLevel(const QCBORDecodeNesting *pNesting)
{
   const ptrdiff_t nLevel = pNesting->pCurrentBounded - &(pNesting->pLevels[0]);
   /*
    Limit in DecodeNesting_Descend against more than
    QCBOR_MAX_ARRAY_NESTING gaurantees cast is safe
    */
   return (uint8_t)nLevel;
}


static inline uint32_t
DecodeNesting_GetMapOrArrayStart(const QCBORDecodeNesting *pNesting)
{
   return pNesting->pCurrentBounded->u.ma.uStartOffset;
}


static inline bool
DecodeNesting_IsBoundedEmpty(const QCBORDecodeNesting *pNesting)
{
   if(pNesting->pCurrentBounded->u.ma.uCountCursor == QCBOR_COUNT_INDICATES_ZERO_LENGTH) {
      return true;
   } else {
      return false;
   }
}


inline static bool
DecodeNesting_IsCurrentAtTop(const QCBORDecodeNesting *pNesting)
{
   if(pNesting->pCurrent == &(pNesting->pLevels[0])) {
      return true;
   } else {
      return false;
   }
}


inline static bool
DecodeNesting_IsCurrentDefiniteLength(const QCBORDecodeNesting *pNesting)
{
   if(pNesting->pCurrent->uLevelType == QCBOR_TYPE_BYTE_STRING) {
      // Not a map or array
      return false;
   }
   if(pNesting->pCurrent->u.ma.uCountTotal == QCBOR_COUNT_INDICATES_INDEFINITE_LENGTH) {
      // Is indefinite
      return false;
   }
   // All checks passed; is a definte length map or array
   return true;
}


inline static bool
DecodeNesting_IsCurrentBstrWrapped(const QCBORDecodeNesting *pNesting)
{
   if(pNesting->pCurrent->uLevelType == QCBOR_TYPE_BYTE_STRING) {
      // is a byte string
      return true;
   }
   return false;
}


inline static bool DecodeNesting_IsCurrentBounded(const QCBORDecodeNesting *pNesting)
{
   if(pNesting->pCurrent->uLevelType == QCBOR_TYPE_BYTE_STRING) {
      return true;
   }
   if(pNesting->pCurrent->u.ma.uStartOffset != QCBOR_NON_BOUNDED_OFFSET) {
      return true;
   }
   return false;
}


inline static void DecodeNesting_SetMapOrArrayBoundedMode(QCBORDecodeNesting *pNesting, bool bIsEmpty, size_t uStart)
{
   // Should be only called on maps and arrays
   /*
    DecodeNesting_EnterBoundedMode() checks to be sure uStart is not
    larger than DecodeNesting_EnterBoundedMode which keeps it less than
    uin32_t so the cast is safe.
    */
   pNesting->pCurrent->u.ma.uStartOffset = (uint32_t)uStart;

   if(bIsEmpty) {
      pNesting->pCurrent->u.ma.uCountCursor = QCBOR_COUNT_INDICATES_ZERO_LENGTH;
   }
}


inline static void DecodeNesting_ClearBoundedMode(QCBORDecodeNesting *pNesting)
{
   pNesting->pCurrent->u.ma.uStartOffset = QCBOR_NON_BOUNDED_OFFSET;
}


inline static bool
DecodeNesting_IsAtEndOfBoundedLevel(const QCBORDecodeNesting *pNesting)
{
   if(pNesting->pCurrentBounded == NULL) {
      // No bounded map or array set up
      return false;
   }
   if(pNesting->pCurrent->uLevelType == QCBOR_TYPE_BYTE_STRING) {
      // Not a map or array; end of those is by byte count
      return false;
   }
   if(!DecodeNesting_IsCurrentBounded(pNesting)) {
      // In a traveral at a level deeper than the bounded level
      return false;
   }
   // Works for both definite and indefinite length maps/arrays
   if(pNesting->pCurrentBounded->u.ma.uCountCursor != 0) {
      // Count is not zero, still unconsumed item
      return false;
   }
   // All checks passed, got to the end of an array or map
   return true;
}


inline static bool
DecodeNesting_IsEndOfDefiniteLengthMapOrArray(const QCBORDecodeNesting *pNesting)
{
   // Must only be called on map / array
   if(pNesting->pCurrent->u.ma.uCountCursor == 0) {
      return true;
   } else {
      return false;
   }
}


inline static bool
DecodeNesting_IsCurrentTypeMap(const QCBORDecodeNesting *pNesting)
{
   if(pNesting->pCurrent->uLevelType == CBOR_MAJOR_TYPE_MAP) {
      return true;
   } else {
      return false;
   }
}


inline static bool
DecodeNesting_IsBoundedType(const QCBORDecodeNesting *pNesting, uint8_t uType)
{
   if(pNesting->pCurrentBounded == NULL) {
      return false;
   }

   if(pNesting->pCurrentBounded->uLevelType != uType) {
      return false;
   }

   return true;
}


inline static void
DecodeNesting_DecrementDefiniteLengthMapOrArrayCount(QCBORDecodeNesting *pNesting)
{
   // Only call on a defnite length array / map
   pNesting->pCurrent->u.ma.uCountCursor--;
}


inline static void
DecodeNesting_ReverseDecrement(QCBORDecodeNesting *pNesting)
{
   // Only call on a defnite length array / map
   pNesting->pCurrent->u.ma.uCountCursor++;
}


inline static void
DecodeNesting_Ascend(QCBORDecodeNesting *pNesting)
{
   pNesting->pCurrent--;
}


static QCBORError
DecodeNesting_Descend(QCBORDecodeNesting *pNesting, uint8_t uType)
{
   // Error out if nesting is too deep
   if(pNesting->pCurrent >= &(pNesting->pLevels[QCBOR_MAX_ARRAY_NESTING])) {
      return QCBOR_ERR_ARRAY_DECODE_NESTING_TOO_DEEP;
   }

   // The actual descend
   pNesting->pCurrent++;

   pNesting->pCurrent->uLevelType = uType;

   return QCBOR_SUCCESS;
}


inline static QCBORError
DecodeNesting_EnterBoundedMapOrArray(QCBORDecodeNesting *pNesting, bool bIsEmpty, size_t uOffset)
{
   /*
    Should only be called on map/array.

    Have descended into this before this is called. The job here is
    just to mark it in bounded mode.

    Check against QCBOR_MAX_DECODE_INPUT_SIZE make sure that
    uOffset doesn't collide with QCBOR_NON_BOUNDED_OFFSET
    */
   if(uOffset >= QCBOR_MAX_DECODE_INPUT_SIZE) {
      return QCBOR_ERR_INPUT_TOO_LARGE;
   }

   pNesting->pCurrentBounded = pNesting->pCurrent;

   DecodeNesting_SetMapOrArrayBoundedMode(pNesting, bIsEmpty, uOffset);

   return QCBOR_SUCCESS;
}


inline static QCBORError
DecodeNesting_DescendMapOrArray(QCBORDecodeNesting *pNesting,
                                uint8_t             uQCBORType,
                                uint64_t            uCount)
{
   QCBORError uError = QCBOR_SUCCESS;

   if(uCount == 0) {
      // Nothing to do for empty definite lenth arrays. They are just are
      // effectively the same as an item that is not a map or array
      goto Done;
      // Empty indefinite length maps and arrays are handled elsewhere
   }

   // Error out if arrays is too long to handle
   if(uCount != QCBOR_COUNT_INDICATES_INDEFINITE_LENGTH &&
      uCount > QCBOR_MAX_ITEMS_IN_ARRAY) {
      uError = QCBOR_ERR_ARRAY_DECODE_TOO_LONG;
      goto Done;
   }

   uError = DecodeNesting_Descend(pNesting, uQCBORType);
   if(uError != QCBOR_SUCCESS) {
      goto Done;
   }

   // Fill in the new map/array level. Check above makes casts OK.
   pNesting->pCurrent->u.ma.uCountCursor  = (uint16_t)uCount;
   pNesting->pCurrent->u.ma.uCountTotal   = (uint16_t)uCount;

   DecodeNesting_ClearBoundedMode(pNesting);

Done:
   return uError;;
}


static inline void
DecodeNesting_LevelUpCurrent(QCBORDecodeNesting *pNesting)
{
   pNesting->pCurrent = pNesting->pCurrentBounded - 1;
}


static inline void
DecodeNesting_LevelUpBounded(QCBORDecodeNesting *pNesting)
{
   while(pNesting->pCurrentBounded != &(pNesting->pLevels[0])) {
      pNesting->pCurrentBounded--;
      if(DecodeNesting_IsCurrentBounded(pNesting)) {
         break;
      }
   }
}

static inline void
DecodeNesting_SetCurrentToBoundedLevel(QCBORDecodeNesting *pNesting)
{
   pNesting->pCurrent = pNesting->pCurrentBounded;
}


inline static QCBORError
DecodeNesting_DescendIntoBstrWrapped(QCBORDecodeNesting *pNesting,
                                     uint32_t uEndOffset,
                                     uint32_t uEndOfBstr)
{
   QCBORError uError = QCBOR_SUCCESS;

   uError = DecodeNesting_Descend(pNesting, QCBOR_TYPE_BYTE_STRING);
   if(uError != QCBOR_SUCCESS) {
      goto Done;
   }

   // Fill in the new byte string level
   pNesting->pCurrent->u.bs.uPreviousEndOffset = uEndOffset;
   pNesting->pCurrent->u.bs.uEndOfBstr         = uEndOfBstr;

   // Bstr wrapped levels are always bounded
   pNesting->pCurrentBounded = pNesting->pCurrent;

Done:
   return uError;;
}


static inline void
DecodeNesting_ZeroMapOrArrayCount(QCBORDecodeNesting *pNesting)
{
   pNesting->pCurrent->u.ma.uCountCursor = 0;
}


inline static void
DecodeNesting_Init(QCBORDecodeNesting *pNesting)
{
   /* Assumes that *pNesting has been zero'd before this call. */
   pNesting->pLevels[0].uLevelType = QCBOR_TYPE_BYTE_STRING;
   pNesting->pCurrent = &(pNesting->pLevels[0]);
}


inline static void
DecodeNesting_PrepareForMapSearch(QCBORDecodeNesting *pNesting, QCBORDecodeNesting *pSave)
{
   *pSave = *pNesting;
   pNesting->pCurrent = pNesting->pCurrentBounded;
   pNesting->pCurrent->u.ma.uCountCursor = pNesting->pCurrent->u.ma.uCountTotal;
}


static inline void
DecodeNesting_RestoreFromMapSearch(QCBORDecodeNesting *pNesting, const QCBORDecodeNesting *pSave)
{
   *pNesting = *pSave;
}


static inline uint32_t
DecodeNesting_GetEndOfBstr(const QCBORDecodeNesting *pMe)
{
   return pMe->pCurrentBounded->u.bs.uEndOfBstr;
}


static inline uint32_t
DecodeNesting_GetPreviousBoundedEnd(const QCBORDecodeNesting *pMe)
{
   return pMe->pCurrentBounded->u.bs.uPreviousEndOffset;
}



/*===========================================================================
   QCBORStringAllocate -- STRING ALLOCATOR INVOCATION

   The following four functions are pretty wrappers for invocation of
   the string allocator supplied by the caller.

  ===========================================================================*/

static inline void
StringAllocator_Free(const QCORInternalAllocator *pMe, void *pMem)
{
   (pMe->pfAllocator)(pMe->pAllocateCxt, pMem, 0);
}

// StringAllocator_Reallocate called with pMem NULL is
// equal to StringAllocator_Allocate()
static inline UsefulBuf
StringAllocator_Reallocate(const QCORInternalAllocator *pMe,
                           void *pMem,
                           size_t uSize)
{
   return (pMe->pfAllocator)(pMe->pAllocateCxt, pMem, uSize);
}

static inline UsefulBuf
StringAllocator_Allocate(const QCORInternalAllocator *pMe, size_t uSize)
{
   return (pMe->pfAllocator)(pMe->pAllocateCxt, NULL, uSize);
}

static inline void
StringAllocator_Destruct(const QCORInternalAllocator *pMe)
{
   if(pMe->pfAllocator) {
      (pMe->pfAllocator)(pMe->pAllocateCxt, NULL, 0);
   }
}



/*===========================================================================
 QCBORDecode -- The main implementation of CBOR decoding

 See qcbor/qcbor_decode.h for definition of the object
 used here: QCBORDecodeContext
  ===========================================================================*/
/*
 Public function, see header file
 */
void QCBORDecode_Init(QCBORDecodeContext *me,
                      UsefulBufC EncodedCBOR,
                      QCBORDecodeMode nDecodeMode)
{
   memset(me, 0, sizeof(QCBORDecodeContext));
   UsefulInputBuf_Init(&(me->InBuf), EncodedCBOR);
   // Don't bother with error check on decode mode. If a bad value is
   // passed it will just act as if the default normal mode of 0 was set.
   me->uDecodeMode = (uint8_t)nDecodeMode;
   DecodeNesting_Init(&(me->nesting));
   for(int i = 0; i < QCBOR_NUM_MAPPED_TAGS; i++) {
      me->auMappedTags[i] = CBOR_TAG_INVALID16;
   }
}


/*
 Public function, see header file
 */
void QCBORDecode_SetUpAllocator(QCBORDecodeContext *pMe,
                                QCBORStringAllocate pfAllocateFunction,
                                void *pAllocateContext,
                                bool bAllStrings)
{
   pMe->StringAllocator.pfAllocator   = pfAllocateFunction;
   pMe->StringAllocator.pAllocateCxt  = pAllocateContext;
   pMe->bStringAllocateAll            = bAllStrings;
}


/*
 Public function, see header file
 */
void QCBORDecode_SetCallerConfiguredTagList(QCBORDecodeContext *pMe,
                                            const QCBORTagListIn *pTagList)
{
   // This does nothing now. It is retained for backwards compatibility
   (void)pMe;
   (void)pTagList;
}


/*
 This decodes the fundamental part of a CBOR data item, the type and
 number

 This is the counterpart to QCBOREncode_EncodeHead().

 This does the network->host byte order conversion. The conversion
 here also results in the conversion for floats in addition to that
 for lengths, tags and integer values.

 This returns:
   pnMajorType -- the major type for the item

   puArgument -- the "number" which is used a the value for integers,
               tags and floats and length for strings and arrays

   pnAdditionalInfo -- Pass this along to know what kind of float or
                       if length is indefinite

 The int type is preferred to uint8_t for some variables as this
 avoids integer promotions, can reduce code size and makes
 static analyzers happier.

 @retval QCBOR_ERR_UNSUPPORTED

 @retval QCBOR_ERR_HIT_END
 */
inline static QCBORError DecodeTypeAndNumber(UsefulInputBuf *pUInBuf,
                                              int *pnMajorType,
                                              uint64_t *puArgument,
                                              int *pnAdditionalInfo)
{
   QCBORError nReturn;

   // Get the initial byte that every CBOR data item has
   const int nInitialByte = (int)UsefulInputBuf_GetByte(pUInBuf);

   // Break down the initial byte
   const int nTmpMajorType   = nInitialByte >> 5;
   const int nAdditionalInfo = nInitialByte & 0x1f;

   // Where the number or argument accumulates
   uint64_t uArgument;

   if(nAdditionalInfo >= LEN_IS_ONE_BYTE && nAdditionalInfo <= LEN_IS_EIGHT_BYTES) {
      // Need to get 1,2,4 or 8 additional argument bytes. Map
      // LEN_IS_ONE_BYTE..LEN_IS_EIGHT_BYTES to actual length
      static const uint8_t aIterate[] = {1,2,4,8};

      // Loop getting all the bytes in the argument
      uArgument = 0;
      for(int i = aIterate[nAdditionalInfo - LEN_IS_ONE_BYTE]; i; i--) {
         // This shift and add gives the endian conversion
         uArgument = (uArgument << 8) + UsefulInputBuf_GetByte(pUInBuf);
      }
   } else if(nAdditionalInfo >= ADDINFO_RESERVED1 && nAdditionalInfo <= ADDINFO_RESERVED3) {
      // The reserved and thus-far unused additional info values
      nReturn = QCBOR_ERR_UNSUPPORTED;
      goto Done;
   } else {
      // Less than 24, additional info is argument or 31, an indefinite length
      // No more bytes to get
      uArgument = (uint64_t)nAdditionalInfo;
   }

   if(UsefulInputBuf_GetError(pUInBuf)) {
      nReturn = QCBOR_ERR_HIT_END;
      goto Done;
   }

   // All successful if we got here.
   nReturn           = QCBOR_SUCCESS;
   *pnMajorType      = nTmpMajorType;
   *puArgument       = uArgument;
   *pnAdditionalInfo = nAdditionalInfo;

Done:
   return nReturn;
}


/*
 CBOR doesn't explicitly specify two's compliment for integers but all
 CPUs use it these days and the test vectors in the RFC are so. All
 integers in the CBOR structure are positive and the major type
 indicates positive or negative.  CBOR can express positive integers
 up to 2^x - 1 where x is the number of bits and negative integers
 down to 2^x.  Note that negative numbers can be one more away from
 zero than positive.  Stdint, as far as I can tell, uses two's
 compliment to represent negative integers.

 See http://www.unix.org/whitepapers/64bit.html for reasons int is
 used carefully here, and in particular why it isn't used in the interface.
 Also see
 https://stackoverflow.com/questions/17489857/why-is-int-typically-32-bit-on-64-bit-compilers

 Int is used for values that need less than 16-bits and would be subject
 to integer promotion and complaining by static analyzers.

 @retval QCBOR_ERR_INT_OVERFLOW
 */
inline static QCBORError
DecodeInteger(int nMajorType, uint64_t uNumber, QCBORItem *pDecodedItem)
{
   QCBORError nReturn = QCBOR_SUCCESS;

   if(nMajorType == CBOR_MAJOR_TYPE_POSITIVE_INT) {
      if (uNumber <= INT64_MAX) {
         pDecodedItem->val.int64 = (int64_t)uNumber;
         pDecodedItem->uDataType = QCBOR_TYPE_INT64;

      } else {
         pDecodedItem->val.uint64 = uNumber;
         pDecodedItem->uDataType  = QCBOR_TYPE_UINT64;

      }
   } else {
      if(uNumber <= INT64_MAX) {
         // CBOR's representation of negative numbers lines up with the
         // two-compliment representation. A negative integer has one
         // more in range than a positive integer. INT64_MIN is
         // equal to (-INT64_MAX) - 1.
         pDecodedItem->val.int64 = (-(int64_t)uNumber) - 1;
         pDecodedItem->uDataType = QCBOR_TYPE_INT64;

      } else {
         // C can't represent a negative integer in this range
         // so it is an error.
         nReturn = QCBOR_ERR_INT_OVERFLOW;
      }
   }

   return nReturn;
}

// Make sure #define value line up as DecodeSimple counts on this.
#if QCBOR_TYPE_FALSE != CBOR_SIMPLEV_FALSE
#error QCBOR_TYPE_FALSE macro value wrong
#endif

#if QCBOR_TYPE_TRUE != CBOR_SIMPLEV_TRUE
#error QCBOR_TYPE_TRUE macro value wrong
#endif

#if QCBOR_TYPE_NULL != CBOR_SIMPLEV_NULL
#error QCBOR_TYPE_NULL macro value wrong
#endif

#if QCBOR_TYPE_UNDEF != CBOR_SIMPLEV_UNDEF
#error QCBOR_TYPE_UNDEF macro value wrong
#endif

#if QCBOR_TYPE_BREAK != CBOR_SIMPLE_BREAK
#error QCBOR_TYPE_BREAK macro value wrong
#endif

#if QCBOR_TYPE_DOUBLE != DOUBLE_PREC_FLOAT
#error QCBOR_TYPE_DOUBLE macro value wrong
#endif

#if QCBOR_TYPE_FLOAT != SINGLE_PREC_FLOAT
#error QCBOR_TYPE_FLOAT macro value wrong
#endif

/*
 Decode true, false, floats, break...

 @retval QCBOR_ERR_HALF_PRECISION_DISABLED

 @retval QCBOR_ERR_BAD_TYPE_7
 */
inline static QCBORError
DecodeSimple(int nAdditionalInfo, uint64_t uNumber, QCBORItem *pDecodedItem)
{
   QCBORError nReturn = QCBOR_SUCCESS;

   // uAdditionalInfo is 5 bits from the initial byte. Compile time checks
   // above make sure uAdditionalInfo values line up with uDataType values.
   // DecodeTypeAndNumber() never returns an AdditionalInfo > 0x1f so cast
   // is safe
   pDecodedItem->uDataType = (uint8_t)nAdditionalInfo;

   switch(nAdditionalInfo) {
      // No check for ADDINFO_RESERVED1 - ADDINFO_RESERVED3 as they are
      // caught before this is called.

      case HALF_PREC_FLOAT: // 25
#ifndef QCBOR_DISABLE_PREFERRED_FLOAT
         // Half-precision is returned as a double.
         // The cast to uint16_t is safe because the encoded value
         // was 16 bits. It was widened to 64 bits to be passed in here.
         pDecodedItem->val.dfnum = IEEE754_HalfToDouble((uint16_t)uNumber);
         pDecodedItem->uDataType = QCBOR_TYPE_DOUBLE;
#else
         nReturn = QCBOR_ERR_HALF_PRECISION_DISABLED;
#endif
         break;
      case SINGLE_PREC_FLOAT: // 26
         // Single precision is normally returned as a double
         // since double is widely supported, there is no loss of
         // precision, it makes it easy for the caller in
         // most cases and it can be converted back to single
         // with no loss of precision
         //
         // The cast to uint32_t is safe because the encoded value
         // was 32 bits. It was widened to 64 bits to be passed in here.
         {
            const float f = UsefulBufUtil_CopyUint32ToFloat((uint32_t)uNumber);
#ifndef QCBOR_DISABLE_FLOAT_HW_USE
            // In the normal case, use HW to convert float to double.
            pDecodedItem->val.dfnum = (double)f;
            pDecodedItem->uDataType = QCBOR_TYPE_DOUBLE;
#else
            // Use of float HW is disabled, return as a float.
            pDecodedItem->val.fnum = f;
            pDecodedItem->uDataType = QCBOR_TYPE_FLOAT;

            // IEEE754_FloatToDouble() could be used here to return
            // as a double, but it adds object code and most likely
            // anyone disabling FLOAT HW use doesn't care about
            // floats and wants to save object code.
#endif
         }
         break;

      case DOUBLE_PREC_FLOAT: // 27
         pDecodedItem->val.dfnum = UsefulBufUtil_CopyUint64ToDouble(uNumber);
         pDecodedItem->uDataType = QCBOR_TYPE_DOUBLE;
         break;

      case CBOR_SIMPLEV_FALSE: // 20
      case CBOR_SIMPLEV_TRUE:  // 21
      case CBOR_SIMPLEV_NULL:  // 22
      case CBOR_SIMPLEV_UNDEF: // 23
      case CBOR_SIMPLE_BREAK:  // 31
         break; // nothing to do

      case CBOR_SIMPLEV_ONEBYTE: // 24
         if(uNumber <= CBOR_SIMPLE_BREAK) {
            // This takes out f8 00 ... f8 1f which should be encoded as e0 … f7
            nReturn = QCBOR_ERR_BAD_TYPE_7;
            goto Done;
         }
         /* FALLTHROUGH */
         // fall through intentionally

      default: // 0-19
         pDecodedItem->uDataType   = QCBOR_TYPE_UKNOWN_SIMPLE;
         /*
          DecodeTypeAndNumber will make uNumber equal to
          uAdditionalInfo when uAdditionalInfo is < 24 This cast is
          safe because the 2, 4 and 8 byte lengths of uNumber are in
          the double/float cases above
          */
         pDecodedItem->val.uSimple = (uint8_t)uNumber;
         break;
   }

Done:
   return nReturn;
}


/*
 Decode text and byte strings. Call the string allocator if asked to.

 @retval QCBOR_ERR_HIT_END

 @retval QCBOR_ERR_STRING_ALLOCATE

 @retval QCBOR_ERR_STRING_TOO_LONG
 */
inline static QCBORError DecodeBytes(const QCORInternalAllocator *pAllocator,
                                     int nMajorType,
                                     uint64_t uStrLen,
                                     UsefulInputBuf *pUInBuf,
                                     QCBORItem *pDecodedItem)
{
   QCBORError nReturn = QCBOR_SUCCESS;

   // CBOR lengths can be 64 bits, but size_t is not 64 bits on all CPUs.
   // This check makes the casts to size_t below safe.

   // 4 bytes less than the largest sizeof() so this can be tested by
   // putting a SIZE_MAX length in the CBOR test input (no one will
   // care the limit on strings is 4 bytes shorter).
   if(uStrLen > SIZE_MAX-4) {
      nReturn = QCBOR_ERR_STRING_TOO_LONG;
      goto Done;
   }

   const UsefulBufC Bytes = UsefulInputBuf_GetUsefulBuf(pUInBuf, (size_t)uStrLen);
   if(UsefulBuf_IsNULLC(Bytes)) {
      // Failed to get the bytes for this string item
      nReturn = QCBOR_ERR_HIT_END;
      goto Done;
   }

   if(pAllocator) {
      // We are asked to use string allocator to make a copy
      UsefulBuf NewMem = StringAllocator_Allocate(pAllocator, (size_t)uStrLen);
      if(UsefulBuf_IsNULL(NewMem)) {
         nReturn = QCBOR_ERR_STRING_ALLOCATE;
         goto Done;
      }
      pDecodedItem->val.string = UsefulBuf_Copy(NewMem, Bytes);
      pDecodedItem->uDataAlloc = 1;
   } else {
      // Normal case with no string allocator
      pDecodedItem->val.string = Bytes;
   }
   const bool bIsBstr = (nMajorType == CBOR_MAJOR_TYPE_BYTE_STRING);
   // Cast because ternary operator causes promotion to integer
   pDecodedItem->uDataType = (uint8_t)(bIsBstr ? QCBOR_TYPE_BYTE_STRING
                                               : QCBOR_TYPE_TEXT_STRING);

Done:
   return nReturn;
}







// Make sure the constants align as this is assumed by
// the GetAnItem() implementation
#if QCBOR_TYPE_ARRAY != CBOR_MAJOR_TYPE_ARRAY
#error QCBOR_TYPE_ARRAY value not lined up with major type
#endif
#if QCBOR_TYPE_MAP != CBOR_MAJOR_TYPE_MAP
#error QCBOR_TYPE_MAP value not lined up with major type
#endif

/*
 This gets a single data item and decodes it including preceding
 optional tagging. This does not deal with arrays and maps and nesting
 except to decode the data item introducing them. Arrays and maps are
 handled at the next level up in GetNext().

 Errors detected here include: an array that is too long to decode,
 hit end of buffer unexpectedly, a few forms of invalid encoded CBOR

 @retval QCBOR_ERR_UNSUPPORTED

 @retval QCBOR_ERR_HIT_END

 @retval QCBOR_ERR_INT_OVERFLOW

 @retval QCBOR_ERR_STRING_ALLOCATE

 @retval QCBOR_ERR_STRING_TOO_LONG

 @retval QCBOR_ERR_HALF_PRECISION_DISABLED

 @retval QCBOR_ERR_BAD_TYPE_7

 */
static QCBORError GetNext_Item(UsefulInputBuf *pUInBuf,
                               QCBORItem *pDecodedItem,
                               const QCORInternalAllocator *pAllocator)
{
   QCBORError nReturn;

   /*
    Get the major type and the number. Number could be length of more
    bytes or the value depending on the major type nAdditionalInfo is
    an encoding of the length of the uNumber and is needed to decode
    floats and doubles
   */
   int      nMajorType = 0;
   uint64_t uNumber = 0;
   int      nAdditionalInfo = 0;

   memset(pDecodedItem, 0, sizeof(QCBORItem));

   nReturn = DecodeTypeAndNumber(pUInBuf, &nMajorType, &uNumber, &nAdditionalInfo);

   // Error out here if we got into trouble on the type and number.  The
   // code after this will not work if the type and number is not good.
   if(nReturn) {
      goto Done;
   }

   // At this point the major type and the value are valid. We've got
   // the type and the number that starts every CBOR data item.
   switch (nMajorType) {
      case CBOR_MAJOR_TYPE_POSITIVE_INT: // Major type 0
      case CBOR_MAJOR_TYPE_NEGATIVE_INT: // Major type 1
         if(nAdditionalInfo == LEN_IS_INDEFINITE) {
            nReturn = QCBOR_ERR_BAD_INT;
         } else {
            nReturn = DecodeInteger(nMajorType, uNumber, pDecodedItem);
         }
         break;

      case CBOR_MAJOR_TYPE_BYTE_STRING: // Major type 2
      case CBOR_MAJOR_TYPE_TEXT_STRING: // Major type 3
         if(nAdditionalInfo == LEN_IS_INDEFINITE) {
            const bool bIsBstr = (nMajorType == CBOR_MAJOR_TYPE_BYTE_STRING);
            pDecodedItem->uDataType = (uint8_t)(bIsBstr ? QCBOR_TYPE_BYTE_STRING
                                                        : QCBOR_TYPE_TEXT_STRING);
            pDecodedItem->val.string = (UsefulBufC){NULL, SIZE_MAX};
         } else {
            nReturn = DecodeBytes(pAllocator, nMajorType, uNumber, pUInBuf, pDecodedItem);
         }
         break;

      case CBOR_MAJOR_TYPE_ARRAY: // Major type 4
      case CBOR_MAJOR_TYPE_MAP:   // Major type 5
         // Record the number of items in the array or map
         if(uNumber > QCBOR_MAX_ITEMS_IN_ARRAY) {
            nReturn = QCBOR_ERR_ARRAY_DECODE_TOO_LONG;
            goto Done;
         }
         if(nAdditionalInfo == LEN_IS_INDEFINITE) {
            pDecodedItem->val.uCount = QCBOR_COUNT_INDICATES_INDEFINITE_LENGTH;
         } else {
            // type conversion OK because of check above
            pDecodedItem->val.uCount = (uint16_t)uNumber;
         }
         // C preproc #if above makes sure constants for major types align
         // DecodeTypeAndNumber never returns a major type > 7 so cast is safe
         pDecodedItem->uDataType  = (uint8_t)nMajorType;
         break;

      case CBOR_MAJOR_TYPE_OPTIONAL: // Major type 6, optional prepended tags
         if(nAdditionalInfo == LEN_IS_INDEFINITE) {
            nReturn = QCBOR_ERR_BAD_INT;
         } else {
            pDecodedItem->val.uTagV = uNumber;
            pDecodedItem->uDataType = QCBOR_TYPE_TAG;
         }
         break;

      case CBOR_MAJOR_TYPE_SIMPLE:
         // Major type 7, float, double, true, false, null...
         nReturn = DecodeSimple(nAdditionalInfo, uNumber, pDecodedItem);
         break;

      default:
         // Never happens because DecodeTypeAndNumber() should never return > 7
         nReturn = QCBOR_ERR_UNSUPPORTED;
         break;
   }

Done:
   return nReturn;
}



/*
 This layer deals with indefinite length strings. It pulls all the
 individual chunk items together into one QCBORItem using the string
 allocator.

 Code Reviewers: THIS FUNCTION DOES A LITTLE POINTER MATH

 @retval QCBOR_ERR_UNSUPPORTED

 @retval QCBOR_ERR_HIT_END

 @retval QCBOR_ERR_INT_OVERFLOW

 @retval QCBOR_ERR_STRING_ALLOCATE

 @retval QCBOR_ERR_STRING_TOO_LONG

 @retval QCBOR_ERR_HALF_PRECISION_DISABLED

 @retval QCBOR_ERR_BAD_TYPE_7

 @retval QCBOR_ERR_NO_STRING_ALLOCATOR

 @retval QCBOR_ERR_INDEFINITE_STRING_CHUNK
 */
static inline QCBORError
GetNext_FullItem(QCBORDecodeContext *me, QCBORItem *pDecodedItem)
{
   // Stack usage; int/ptr 2 UsefulBuf 2 QCBORItem  -- 96

   // Get pointer to string allocator. First use is to pass it to
   // GetNext_Item() when option is set to allocate for *every* string.
   // Second use here is to allocate space to coallese indefinite
   // length string items into one.
   const QCORInternalAllocator *pAllocator = me->StringAllocator.pfAllocator ?
                                                      &(me->StringAllocator) :
                                                      NULL;

   QCBORError nReturn;
   nReturn = GetNext_Item(&(me->InBuf),
                          pDecodedItem,
                          me->bStringAllocateAll ? pAllocator: NULL);
   if(nReturn) {
      goto Done;
   }

   // To reduce code size by removing support for indefinite length strings, the
   // code in this function from here down can be eliminated. Run tests, except
   // indefinite length string tests, to be sure all is OK if this is removed.

   // Only do indefinite length processing on strings
   const uint8_t uStringType = pDecodedItem->uDataType;
   if(uStringType!= QCBOR_TYPE_BYTE_STRING && uStringType != QCBOR_TYPE_TEXT_STRING) {
      goto Done; // no need to do any work here on non-string types
   }

   // Is this a string with an indefinite length?
   if(pDecodedItem->val.string.len != SIZE_MAX) {
      goto Done; // length is not indefinite, so no work to do here
   }

   // Can't do indefinite length strings without a string allocator
   if(pAllocator == NULL) {
      nReturn = QCBOR_ERR_NO_STRING_ALLOCATOR;
      goto Done;
   }

   // Loop getting chunks of the indefinite length string
   UsefulBufC FullString = NULLUsefulBufC;

   for(;;) {
      // Get item for next chunk
      QCBORItem StringChunkItem;
      // NULL string allocator passed here. Do not need to allocate
      // chunks even if bStringAllocateAll is set.
      nReturn = GetNext_Item(&(me->InBuf), &StringChunkItem, NULL);
      if(nReturn) {
         break;  // Error getting the next chunk
      }

      // See if it is a marker at end of indefinite length string
      if(StringChunkItem.uDataType == QCBOR_TYPE_BREAK) {
         // String is complete
         pDecodedItem->val.string = FullString;
         pDecodedItem->uDataAlloc = 1;
         break;
      }

      // Match data type of chunk to type at beginning.
      // Also catches error of other non-string types that don't belong.
      // Also catches indefinite length strings inside indefinite length strings
      if(StringChunkItem.uDataType != uStringType ||
         StringChunkItem.val.string.len == SIZE_MAX) {
         nReturn = QCBOR_ERR_INDEFINITE_STRING_CHUNK;
         break;
      }

      // Alloc new buffer or expand previously allocated buffer so it can fit
      // The first time throurgh FullString.ptr is NULL and this is
      // equivalent to StringAllocator_Allocate()
      UsefulBuf NewMem = StringAllocator_Reallocate(pAllocator,
                                                    UNCONST_POINTER(FullString.ptr),
                                                    FullString.len + StringChunkItem.val.string.len);

      if(UsefulBuf_IsNULL(NewMem)) {
         // Allocation of memory for the string failed
         nReturn = QCBOR_ERR_STRING_ALLOCATE;
         break;
      }

      // Copy new string chunk at the end of string so far.
      FullString = UsefulBuf_CopyOffset(NewMem, FullString.len, StringChunkItem.val.string);
   }

   if(nReturn != QCBOR_SUCCESS && !UsefulBuf_IsNULLC(FullString)) {
      // Getting the item failed, clean up the allocated memory
      StringAllocator_Free(pAllocator, UNCONST_POINTER(FullString.ptr));
   }

Done:
   return nReturn;
}

static uint64_t ConvertTag(const QCBORDecodeContext *me, uint16_t uTagVal) {
   if(uTagVal <= QCBOR_LAST_UNMAPPED_TAG) {
      return uTagVal;
   } else if(uTagVal == CBOR_TAG_INVALID16) {
      return CBOR_TAG_INVALID64;
   } else {
      const int x = uTagVal - (QCBOR_LAST_UNMAPPED_TAG + 1);
      return me->auMappedTags[x];
   }
}


/*
 Gets all optional tag data items preceding a data item that is not an
 optional tag and records them as bits in the tag map.

 @retval QCBOR_ERR_UNSUPPORTED

 @retval QCBOR_ERR_HIT_END

 @retval QCBOR_ERR_INT_OVERFLOW

 @retval QCBOR_ERR_STRING_ALLOCATE

 @retval QCBOR_ERR_STRING_TOO_LONG

 @retval QCBOR_ERR_HALF_PRECISION_DISABLED

 @retval QCBOR_ERR_BAD_TYPE_7

 @retval QCBOR_ERR_NO_STRING_ALLOCATOR

 @retval QCBOR_ERR_INDEFINITE_STRING_CHUNK

 @retval QCBOR_ERR_TOO_MANY_TAGS
 */
static QCBORError
GetNext_TaggedItem(QCBORDecodeContext *me, QCBORItem *pDecodedItem)
{
   uint16_t auTags[QCBOR_MAX_TAGS_PER_ITEM] = {CBOR_TAG_INVALID16,
                                               CBOR_TAG_INVALID16,
                                               CBOR_TAG_INVALID16,
                                               CBOR_TAG_INVALID16};

   QCBORError uReturn = QCBOR_SUCCESS;

   // Loop fetching items until the item fetched is not a tag
   for(;;) {
      QCBORError uErr = GetNext_FullItem(me, pDecodedItem);
      if(uErr != QCBOR_SUCCESS) {
         uReturn = uErr;
         goto Done; // Error out of the loop
      }

      if(pDecodedItem->uDataType != QCBOR_TYPE_TAG) {
         // Successful exit from loop; maybe got some tags, maybe not
         memcpy(pDecodedItem->uTags, auTags, sizeof(auTags));
         break;
      }

      if(auTags[QCBOR_MAX_TAGS_PER_ITEM - 1] != CBOR_TAG_INVALID16) {
         // No room in the tag list
         uReturn = QCBOR_ERR_TOO_MANY_TAGS;
         // Continue on to get all tags on this item even though
         // it is erroring out in the end. This is a resource limit
         // error, not a problem with being well-formed CBOR.
         continue;
      }
      // Slide tags over one in the array to make room at index 0
      for(size_t uTagIndex = QCBOR_MAX_TAGS_PER_ITEM - 1; uTagIndex > 0; uTagIndex--) {
         auTags[uTagIndex] = auTags[uTagIndex-1];
      }

      // Is the tag > 16 bits?
      if(pDecodedItem->val.uTagV > QCBOR_LAST_UNMAPPED_TAG) {
         size_t uTagMapIndex;
         // Is there room in the tag map, or is it in it already?
         for(uTagMapIndex = 0; uTagMapIndex < QCBOR_NUM_MAPPED_TAGS; uTagMapIndex++) {
            if(me->auMappedTags[uTagMapIndex] == CBOR_TAG_INVALID16) {
               break;
            }
            if(me->auMappedTags[uTagMapIndex] == pDecodedItem->val.uTagV) {
               break;
            }
         }
         if(uTagMapIndex >= QCBOR_NUM_MAPPED_TAGS) {
            // No room for the tag
            uReturn = QCBOR_ERR_TOO_MANY_TAGS;
            // Continue on to get all tags on this item even though
            // it is erroring out in the end. This is a resource limit
            // error, not a problem with being well-formed CBOR.
            continue;
         }

         // Covers the cases where tag is new and were it is already in the map
         me->auMappedTags[uTagMapIndex] = pDecodedItem->val.uTagV;
         auTags[0] = (uint16_t)(uTagMapIndex + QCBOR_LAST_UNMAPPED_TAG + 1);

      } else {
         auTags[0] = (uint16_t)pDecodedItem->val.uTagV;
      }
   }

Done:
   return uReturn;
}


/*
 This layer takes care of map entries. It combines the label and data
 items into one QCBORItem.

 @retval QCBOR_ERR_UNSUPPORTED

 @retval QCBOR_ERR_HIT_END

 @retval QCBOR_ERR_INT_OVERFLOW

 @retval QCBOR_ERR_STRING_ALLOCATE

 @retval QCBOR_ERR_STRING_TOO_LONG

 @retval QCBOR_ERR_HALF_PRECISION_DISABLED

 @retval QCBOR_ERR_BAD_TYPE_7

 @retval QCBOR_ERR_NO_STRING_ALLOCATOR

 @retval QCBOR_ERR_INDEFINITE_STRING_CHUNK

 @retval QCBOR_ERR_TOO_MANY_TAGS

 @retval QCBOR_ERR_MAP_LABEL_TYPE

 @retval QCBOR_ERR_ARRAY_DECODE_TOO_LONG
 */
static inline QCBORError
GetNext_MapEntry(QCBORDecodeContext *me, QCBORItem *pDecodedItem)
{
   // Stack use: int/ptr 1, QCBORItem  -- 56
   QCBORError nReturn = GetNext_TaggedItem(me, pDecodedItem);
   if(nReturn)
      goto Done;

   if(pDecodedItem->uDataType == QCBOR_TYPE_BREAK) {
      // Break can't be a map entry
      goto Done;
   }

   if(me->uDecodeMode != QCBOR_DECODE_MODE_MAP_AS_ARRAY) {
      // In a map and caller wants maps decoded, not treated as arrays

      if(DecodeNesting_IsCurrentTypeMap(&(me->nesting))) {
         // If in a map and the right decoding mode, get the label

         // Save label in pDecodedItem and get the next which will
         // be the real data
         QCBORItem LabelItem = *pDecodedItem;
         nReturn = GetNext_TaggedItem(me, pDecodedItem);
         if(QCBORDecode_IsUnrecoverableError(nReturn)) {
            goto Done;
         }

         pDecodedItem->uLabelAlloc = LabelItem.uDataAlloc;

         if(LabelItem.uDataType == QCBOR_TYPE_TEXT_STRING) {
            // strings are always good labels
            pDecodedItem->label.string = LabelItem.val.string;
            pDecodedItem->uLabelType = QCBOR_TYPE_TEXT_STRING;
         } else if (QCBOR_DECODE_MODE_MAP_STRINGS_ONLY == me->uDecodeMode) {
            // It's not a string and we only want strings
            nReturn = QCBOR_ERR_MAP_LABEL_TYPE;
            goto Done;
         } else if(LabelItem.uDataType == QCBOR_TYPE_INT64) {
            pDecodedItem->label.int64 = LabelItem.val.int64;
            pDecodedItem->uLabelType = QCBOR_TYPE_INT64;
         } else if(LabelItem.uDataType == QCBOR_TYPE_UINT64) {
            pDecodedItem->label.uint64 = LabelItem.val.uint64;
            pDecodedItem->uLabelType = QCBOR_TYPE_UINT64;
         } else if(LabelItem.uDataType == QCBOR_TYPE_BYTE_STRING) {
            pDecodedItem->label.string = LabelItem.val.string;
            pDecodedItem->uLabelAlloc = LabelItem.uDataAlloc;
            pDecodedItem->uLabelType = QCBOR_TYPE_BYTE_STRING;
         } else {
            // label is not an int or a string. It is an arrray
            // or a float or such and this implementation doesn't handle that.
            // Also, tags on labels are ignored.
            nReturn = QCBOR_ERR_MAP_LABEL_TYPE;
            goto Done;
         }
      }
   } else {
      if(pDecodedItem->uDataType == QCBOR_TYPE_MAP) {
         if(pDecodedItem->val.uCount > QCBOR_MAX_ITEMS_IN_ARRAY/2) {
            nReturn = QCBOR_ERR_ARRAY_DECODE_TOO_LONG;
            goto Done;
         }
         // Decoding a map as an array
         pDecodedItem->uDataType = QCBOR_TYPE_MAP_AS_ARRAY;
         // Cast is safe because of check against QCBOR_MAX_ITEMS_IN_ARRAY/2
         // Cast is needed because of integer promotion
         pDecodedItem->val.uCount = (uint16_t)(pDecodedItem->val.uCount * 2);
      }
   }

Done:
   return nReturn;
}


/*
 See if next item is a CBOR break. If it is, it is consumed,
 if not it is not consumed.
*/
static inline QCBORError
NextIsBreak(UsefulInputBuf *pUIB, bool *pbNextIsBreak)
{
   *pbNextIsBreak = false;
   if(UsefulInputBuf_BytesUnconsumed(pUIB) != 0) {
      QCBORItem Peek;
      size_t uPeek = UsefulInputBuf_Tell(pUIB);
      QCBORError uReturn = GetNext_Item(pUIB, &Peek, NULL);
      if(uReturn != QCBOR_SUCCESS) {
         return uReturn;
      }
      if(Peek.uDataType != QCBOR_TYPE_BREAK) {
         // It is not a break, rewind so it can be processed normally.
         UsefulInputBuf_Seek(pUIB, uPeek);
      } else {
         *pbNextIsBreak = true;
      }
   }

   return QCBOR_SUCCESS;
}


/*
 An item was just consumed, now figure out if it was the
 end of an array or map that can be closed out. That
 may in turn close out another map or array.
*/
static QCBORError NestLevelAscender(QCBORDecodeContext *pMe, bool bMarkEnd)
{
   QCBORError uReturn;

   /* This loops ascending nesting levels as long as there is ascending to do */
   while(!DecodeNesting_IsCurrentAtTop(&(pMe->nesting))) {

      if(DecodeNesting_IsCurrentDefiniteLength(&(pMe->nesting))) {
         /* Decrement count for definite length maps / arrays */
         DecodeNesting_DecrementDefiniteLengthMapOrArrayCount(&(pMe->nesting));
         if(!DecodeNesting_IsEndOfDefiniteLengthMapOrArray(&(pMe->nesting))) {
             /* Didn't close out map or array, so all work here is done */
             break;
          }
          /* All of a definite length array was consumed; fall through to
             ascend */

      } else {
         /* If not definite length, have to check for a CBOR break */
         bool bIsBreak = false;
         uReturn = NextIsBreak(&(pMe->InBuf), &bIsBreak);
         if(uReturn != QCBOR_SUCCESS) {
            goto Done;
         }

         if(!bIsBreak) {
            /* It's not a break so nothing closes out and all work is done */
            break;
         }

         if(DecodeNesting_IsCurrentBstrWrapped(&(pMe->nesting))) {
            /*
             Break occurred inside a bstr-wrapped CBOR or
             in the top level sequence. This is always an
             error because neither are an indefinte length
             map/array.
             */
            uReturn = QCBOR_ERR_BAD_BREAK;
            goto Done;
         }

         /* It was a break in an indefinite length map / array */
      }

      /* All items in the map/array level have been consumed. */

      /* But ascent in bounded mode is only by explicit call to
         QCBORDecode_ExitBoundedMode() */
      if(DecodeNesting_IsCurrentBounded(&(pMe->nesting))) {
         /* Set the count to zero for definite length arrays to indicate
            cursor is at end of bounded map / array */
         if(bMarkEnd) {
            // Used for definite and indefinite to signal end
            DecodeNesting_ZeroMapOrArrayCount(&(pMe->nesting));

         }
         break;
      }

      /* Finally, actually ascend one level. */
      DecodeNesting_Ascend(&(pMe->nesting));
   }

   uReturn = QCBOR_SUCCESS;

Done:
   return uReturn;
}


/*
 This handles the traversal descending into and asecnding out of maps,
 arrays and bstr-wrapped CBOR. It figures out the ends of definite and
 indefinte length maps and arrays by looking at the item count or
 finding CBOR breaks.  It detects the ends of the top-level sequence
 and of bstr-wrapped CBOR by byte count.

 @retval QCBOR_ERR_UNSUPPORTED X

 @retval QCBOR_ERR_HIT_END

 @retval QCBOR_ERR_INT_OVERFLOW X

 @retval QCBOR_ERR_STRING_ALLOCATE

 @retval QCBOR_ERR_STRING_TOO_LONG

 @retval QCBOR_ERR_HALF_PRECISION_DISABLED X

 @retval QCBOR_ERR_BAD_TYPE_7 X

 @retval QCBOR_ERR_NO_STRING_ALLOCATOR

 @retval QCBOR_ERR_INDEFINITE_STRING_CHUNK

 @retval QCBOR_ERR_TOO_MANY_TAGS

 @retval QCBOR_ERR_MAP_LABEL_TYPE X

 @retval QCBOR_ERR_ARRAY_DECODE_TOO_LONG

 @retval QCBOR_ERR_NO_MORE_ITEMS

 @retval QCBOR_ERR_BAD_BREAK

 */
static QCBORError
QCBORDecode_GetNextMapOrArray(QCBORDecodeContext *me, QCBORItem *pDecodedItem)
{
   QCBORError uReturn;
   /* ==== First: figure out if at the end of a traversal ==== */

   /*
    If out of bytes to consume, it is either the end of the top-level
    sequence of some bstr-wrapped CBOR that was entered.

    In the case of bstr-wrapped CBOR, the length of the UsefulInputBuf
    was set to that of the bstr-wrapped CBOR. When the bstr-wrapped
    CBOR is exited, the length is set back to the top-level's length
    or to the next highest bstr-wrapped CBOR.
   */
   if(UsefulInputBuf_BytesUnconsumed(&(me->InBuf)) == 0) {
      uReturn = QCBOR_ERR_NO_MORE_ITEMS;
      goto Done;
   }

   /*
    Check to see if at the end of a bounded definite length map or
    array. The check for the end of an indefinite length array is
    later.
    */
   if(DecodeNesting_IsAtEndOfBoundedLevel(&(me->nesting))) {
      uReturn = QCBOR_ERR_NO_MORE_ITEMS;
      goto Done;
   }

   /* ==== Next: not at the end so get another item ==== */
   uReturn = GetNext_MapEntry(me, pDecodedItem);
   if(QCBORDecode_IsUnrecoverableError(uReturn)) {
      /* Error is so bad that traversal is not possible. */
      goto Done;
   }

   /*
    Breaks ending arrays/maps are always processed at the end of this
    function. They should never show up here.
    */
   if(pDecodedItem->uDataType == QCBOR_TYPE_BREAK) {
      uReturn = QCBOR_ERR_BAD_BREAK;
      goto Done;
   }

   /*
     Record the nesting level for this data item before processing any
     of decrementing and descending.
    */
   pDecodedItem->uNestingLevel = DecodeNesting_GetCurrentLevel(&(me->nesting));


   /* ==== Next: Process the item for descent, ascent, decrement... ==== */
   if(QCBORItem_IsMapOrArray(pDecodedItem)) {
      /*
       If the new item is a map or array, descend.

       Empty indefinite length maps and arrays are descended into, but
       then ascended out of in the next chunk of code.

       Maps and arrays do count as items in the map/array that
       encloses them so a decrement needs to be done for them too, but
       that is done only when all the items in them have been
       processed, not when they are opened with the exception of an
       empty map or array.
       */
      QCBORError uDescendErr;
      uDescendErr = DecodeNesting_DescendMapOrArray(&(me->nesting),
                                                pDecodedItem->uDataType,
                                                pDecodedItem->val.uCount);
      if(uDescendErr != QCBOR_SUCCESS) {
         /* This error is probably a traversal error and it
          overrides the non-traversal error. */
         uReturn = uDescendErr;
         goto Done;
      }
   }

   if(!QCBORItem_IsMapOrArray(pDecodedItem) ||
       QCBORItem_IsEmptyDefiniteLengthMapOrArray(pDecodedItem) ||
       QCBORItem_IsIndefiniteLengthMapOrArray(pDecodedItem)) {
      /*
       The following cases are handled here:
         - A non-aggregate like an integer or string
         - An empty definite length map or array
         - An indefinite length map or array that might be empty or might not.

       NestLevelAscender() does the work of decrementing the count for an
       definite length map/array and break detection for an indefinite
       length map/array. If the end of the map/array was reached, then
       it ascends nesting levels, possibly all the way to the top level.
       */
      QCBORError uAscendErr;
      uAscendErr = NestLevelAscender(me, true);
      if(uAscendErr != QCBOR_SUCCESS) {
         /* This error is probably a traversal error and it
          overrides the non-traversal error. */
         uReturn = uAscendErr;
         goto Done;
      }
   }

   /* ==== Last: tell the caller the nest level of the next item ==== */
   /*
    Tell the caller what level is next. This tells them what
    maps/arrays were closed out and makes it possible for them to
    reconstruct the tree with just the information returned in
    a QCBORItem.
   */
   if(DecodeNesting_IsAtEndOfBoundedLevel(&(me->nesting))) {
      /* At end of a bounded map/array; uNextNestLevel 0 to indicate this */
      pDecodedItem->uNextNestLevel = 0;
   } else {
      pDecodedItem->uNextNestLevel = DecodeNesting_GetCurrentLevel(&(me->nesting));
   }

Done:
   return uReturn;
}

static void ShiftTags(QCBORItem *pDecodedItem)
{
   pDecodedItem->uTags[0] = pDecodedItem->uTags[1];
   pDecodedItem->uTags[1] = pDecodedItem->uTags[2];
   pDecodedItem->uTags[2] = pDecodedItem->uTags[3];
   pDecodedItem->uTags[2] = CBOR_TAG_INVALID16;
}


/*
 Mostly just assign the right data type for the date string.
 */
inline static QCBORError DecodeDateString(QCBORItem *pDecodedItem)
{
   if(pDecodedItem->uDataType != QCBOR_TYPE_TEXT_STRING) {
      return QCBOR_ERR_BAD_OPT_TAG;
   }

   const UsefulBufC Temp        = pDecodedItem->val.string;
   pDecodedItem->val.dateString = Temp;
   pDecodedItem->uDataType      = QCBOR_TYPE_DATE_STRING;
   ShiftTags(pDecodedItem);
   return QCBOR_SUCCESS;
}



/*
 The epoch formatted date. Turns lots of different forms of encoding
 date into uniform one
 */
static QCBORError DecodeDateEpoch(QCBORItem *pDecodedItem)
{
   QCBORError uReturn = QCBOR_SUCCESS;

   pDecodedItem->val.epochDate.fSecondsFraction = 0;

   switch (pDecodedItem->uDataType) {

      case QCBOR_TYPE_INT64:
         pDecodedItem->val.epochDate.nSeconds = pDecodedItem->val.int64;
         break;

      case QCBOR_TYPE_UINT64:
         // This only happens for CBOR type 0 > INT64_MAX so it is
         // always an overflow.
         uReturn = QCBOR_ERR_DATE_OVERFLOW;
         goto Done;
         break;

      case QCBOR_TYPE_DOUBLE:
      case QCBOR_TYPE_FLOAT:
#ifndef QCBOR_DISABLE_FLOAT_HW_USE
      {
         // This comparison needs to be done as a float before
         // conversion to an int64_t to be able to detect doubles that
         // are too large to fit into an int64_t.  A double has 52
         // bits of preceision. An int64_t has 63. Casting INT64_MAX
         // to a double actually causes a round up which is bad and
         // wrong for the comparison because it will allow conversion
         // of doubles that can't fit into a uint64_t.  To remedy this
         // INT64_MAX - 0x7ff is used as the cutoff point because if
         // that value rounds up in conversion to double it will still
         // be less than INT64_MAX. 0x7ff is picked because it has 11
         // bits set.
         //
         // INT64_MAX seconds is on the order of 10 billion years, and
         // the earth is less than 5 billion years old, so for most
         // uses this conversion error won't occur even though doubles
         // can go much larger.
         //
         // Without the 0x7ff there is a ~30 minute range of time
         // values 10 billion years in the past and in the future
         // where this code would go wrong. Some compilers
         // will generate warnings or errors without the 0x7ff
         // because of the precision issue.
         const double d = pDecodedItem->uDataType == QCBOR_TYPE_DOUBLE ?
                            pDecodedItem->val.dfnum :
                            (double)pDecodedItem->val.fnum;
         if(isnan(d) ||
            d > (double)(INT64_MAX - 0x7ff) ||
            d < (double)(INT64_MIN + 0x7ff)) {
            uReturn = QCBOR_ERR_DATE_OVERFLOW;
            goto Done;
         }
         pDecodedItem->val.epochDate.nSeconds = (int64_t)d;
         pDecodedItem->val.epochDate.fSecondsFraction =
                           d - (double)pDecodedItem->val.epochDate.nSeconds;
      }
#else

         uReturn = QCBOR_ERR_FLOAT_DATE_DISABLED;
         goto Done;

#endif /* QCBOR_DISABLE_FLOAT_HW_USE */
         break;

      default:
         uReturn = QCBOR_ERR_BAD_OPT_TAG;
         goto Done;
   }

   pDecodedItem->uDataType = QCBOR_TYPE_DATE_EPOCH;

Done:
   return uReturn;
}


/*
 Mostly just assign the right data type for the bignum.
 */
inline static QCBORError DecodeBigNum(QCBORItem *pDecodedItem)
{
   // Stack Use: UsefulBuf 1  -- 16
   if(pDecodedItem->uDataType != QCBOR_TYPE_BYTE_STRING) {
      return QCBOR_ERR_BAD_OPT_TAG;
   }
   const UsefulBufC Temp    = pDecodedItem->val.string;
   pDecodedItem->val.bigNum = Temp;
   const bool bIsPosBigNum = (bool)(pDecodedItem->uTags[0] == CBOR_TAG_POS_BIGNUM);
   pDecodedItem->uDataType  = (uint8_t)(bIsPosBigNum ? QCBOR_TYPE_POSBIGNUM
                                                     : QCBOR_TYPE_NEGBIGNUM);
   return QCBOR_SUCCESS;
}


#ifndef QCBOR_CONFIG_DISABLE_EXP_AND_MANTISSA
/*
 Decode decimal fractions and big floats.

 When called pDecodedItem must be the array that is tagged as a big
 float or decimal fraction, the array that has the two members, the
 exponent and mantissa.

 This will fetch and decode the exponent and mantissa and put the
 result back into pDecodedItem.
 */
inline static QCBORError
QCBORDecode_MantissaAndExponent(QCBORDecodeContext *me, QCBORItem *pDecodedItem)
{
   QCBORError nReturn;

   // --- Make sure it is an array; track nesting level of members ---
   if(pDecodedItem->uDataType != QCBOR_TYPE_ARRAY) {
      nReturn = QCBOR_ERR_BAD_EXP_AND_MANTISSA;
      goto Done;
   }

   // A check for pDecodedItem->val.uCount == 2 would work for
   // definite length arrays, but not for indefnite.  Instead remember
   // the nesting level the two integers must be at, which is one
   // deeper than that of the array.
   const int nNestLevel = pDecodedItem->uNestingLevel + 1;

   // --- Is it a decimal fraction or a bigfloat? ---
   const bool bIsTaggedDecimalFraction = QCBORDecode_IsTagged(me, pDecodedItem, CBOR_TAG_DECIMAL_FRACTION);
   pDecodedItem->uDataType = bIsTaggedDecimalFraction ? QCBOR_TYPE_DECIMAL_FRACTION : QCBOR_TYPE_BIGFLOAT;

   // --- Get the exponent ---
   QCBORItem exponentItem;
   nReturn = QCBORDecode_GetNextMapOrArray(me, &exponentItem);
   if(nReturn != QCBOR_SUCCESS) {
      goto Done;
   }
   if(exponentItem.uNestingLevel != nNestLevel) {
      // Array is empty or a map/array encountered when expecting an int
      nReturn = QCBOR_ERR_BAD_EXP_AND_MANTISSA;
      goto Done;
   }
   if(exponentItem.uDataType == QCBOR_TYPE_INT64) {
     // Data arriving as an unsigned int < INT64_MAX has been converted
     // to QCBOR_TYPE_INT64 and thus handled here. This is also means
     // that the only data arriving here of type QCBOR_TYPE_UINT64 data
     // will be too large for this to handle and thus an error that will
     // get handled in the next else.
     pDecodedItem->val.expAndMantissa.nExponent = exponentItem.val.int64;
   } else {
      // Wrong type of exponent or a QCBOR_TYPE_UINT64 > INT64_MAX
      nReturn = QCBOR_ERR_BAD_EXP_AND_MANTISSA;
      goto Done;
   }

   // --- Get the mantissa ---
   QCBORItem mantissaItem;
   nReturn = QCBORDecode_GetNextWithTags(me, &mantissaItem, NULL);
   if(nReturn != QCBOR_SUCCESS) {
      goto Done;
   }
   if(mantissaItem.uNestingLevel != nNestLevel) {
      // Mantissa missing or map/array encountered when expecting number
      nReturn = QCBOR_ERR_BAD_EXP_AND_MANTISSA;
      goto Done;
   }
   if(mantissaItem.uDataType == QCBOR_TYPE_INT64) {
      // Data arriving as an unsigned int < INT64_MAX has been converted
      // to QCBOR_TYPE_INT64 and thus handled here. This is also means
      // that the only data arriving here of type QCBOR_TYPE_UINT64 data
      // will be too large for this to handle and thus an error that
      // will get handled in an else below.
      pDecodedItem->val.expAndMantissa.Mantissa.nInt = mantissaItem.val.int64;
   }  else if(mantissaItem.uDataType == QCBOR_TYPE_POSBIGNUM ||
              mantissaItem.uDataType == QCBOR_TYPE_NEGBIGNUM) {
      // Got a good big num mantissa
      pDecodedItem->val.expAndMantissa.Mantissa.bigNum = mantissaItem.val.bigNum;
      // Depends on numbering of QCBOR_TYPE_XXX
      pDecodedItem->uDataType = (uint8_t)(pDecodedItem->uDataType +
                                          mantissaItem.uDataType - QCBOR_TYPE_POSBIGNUM +
                                          1);
   } else {
      // Wrong type of mantissa or a QCBOR_TYPE_UINT64 > INT64_MAX
      nReturn = QCBOR_ERR_BAD_EXP_AND_MANTISSA;
      goto Done;
   }

   // --- Check that array only has the two numbers ---
   if(mantissaItem.uNextNestLevel == nNestLevel) {
      // Extra items in the decimal fraction / big float
      nReturn = QCBOR_ERR_BAD_EXP_AND_MANTISSA;
      goto Done;
   }
   pDecodedItem->uNextNestLevel = mantissaItem.uNextNestLevel;

Done:
  return nReturn;
}
#endif /* QCBOR_CONFIG_DISABLE_EXP_AND_MANTISSA */


inline static QCBORError DecodeURI(QCBORItem *pDecodedItem)
{
   if(pDecodedItem->uDataType != QCBOR_TYPE_TEXT_STRING) {
      return QCBOR_ERR_BAD_OPT_TAG;
   }
   pDecodedItem->uDataType = QCBOR_TYPE_URI;
   return QCBOR_SUCCESS;
}


inline static QCBORError DecodeB64URL(QCBORItem *pDecodedItem)
{
   if(pDecodedItem->uDataType != QCBOR_TYPE_TEXT_STRING) {
      return QCBOR_ERR_BAD_OPT_TAG;
   }
   pDecodedItem->uDataType = QCBOR_TYPE_BASE64URL;

   return QCBOR_SUCCESS;
}


inline static QCBORError DecodeB64(QCBORItem *pDecodedItem)
{
   if(pDecodedItem->uDataType != QCBOR_TYPE_TEXT_STRING) {
      return QCBOR_ERR_BAD_OPT_TAG;
   }
   pDecodedItem->uDataType = QCBOR_TYPE_BASE64;

   return QCBOR_SUCCESS;
}


inline static QCBORError DecodeRegex(QCBORItem *pDecodedItem)
{
   if(pDecodedItem->uDataType != QCBOR_TYPE_TEXT_STRING) {
      return QCBOR_ERR_BAD_OPT_TAG;
   }
   pDecodedItem->uDataType = QCBOR_TYPE_REGEX;

   return QCBOR_SUCCESS;
}


inline static QCBORError DecodeWrappedCBOR(QCBORItem *pDecodedItem)
{
   if(pDecodedItem->uDataType != QCBOR_TYPE_BYTE_STRING) {
      return QCBOR_ERR_BAD_OPT_TAG;
   }
   pDecodedItem->uDataType = QBCOR_TYPE_WRAPPED_CBOR;

   return QCBOR_SUCCESS;
}


inline static QCBORError DecodeWrappedCBORSequence(QCBORItem *pDecodedItem)
{
   if(pDecodedItem->uDataType != QCBOR_TYPE_BYTE_STRING) {
      return QCBOR_ERR_BAD_OPT_TAG;
   }
   pDecodedItem->uDataType = QBCOR_TYPE_WRAPPED_CBOR_SEQUENCE;

   return QCBOR_SUCCESS;
}


inline static QCBORError DecodeMIME(QCBORItem *pDecodedItem)
{
   if(pDecodedItem->uDataType == QCBOR_TYPE_TEXT_STRING) {
      pDecodedItem->uDataType = QCBOR_TYPE_MIME;
   } else if(pDecodedItem->uDataType == QCBOR_TYPE_BYTE_STRING) {
      pDecodedItem->uDataType = QCBOR_TYPE_BINARY_MIME;
   } else {
      return QCBOR_ERR_BAD_OPT_TAG;

   }

   return QCBOR_SUCCESS;
}


inline static QCBORError DecodeUUID(QCBORItem *pDecodedItem)
{
   if(pDecodedItem->uDataType != QCBOR_TYPE_BYTE_STRING) {
      return QCBOR_ERR_BAD_OPT_TAG;
   }
   pDecodedItem->uDataType = QCBOR_TYPE_UUID;

   return QCBOR_SUCCESS;
}


/*
 Public function, see header qcbor/qcbor_decode.h file
 */
static QCBORError
QCBORDecode_GetNextTag(QCBORDecodeContext *me, QCBORItem *pDecodedItem)
{
   QCBORError nReturn;

   nReturn = QCBORDecode_GetNextMapOrArray(me, pDecodedItem);
   if(nReturn != QCBOR_SUCCESS) {
      goto Done;
   }

   for(int i = 0; i < QCBOR_MAX_TAGS_PER_ITEM; i++) {
      switch(pDecodedItem->uTags[i]) {

         // Many of the functions here only just map a CBOR tag to
         // a QCBOR_TYPE for a string and could probably be
         // implemented with less object code. This implementation
         // of string types takes about 120 bytes of object code
         // (that is always linked and not removed by dead stripping).
         case CBOR_TAG_DATE_STRING:
         nReturn = DecodeDateString(pDecodedItem);
         break;

         case CBOR_TAG_DATE_EPOCH:
         nReturn = DecodeDateEpoch(pDecodedItem);
         break;

         case CBOR_TAG_POS_BIGNUM:
         case CBOR_TAG_NEG_BIGNUM:
         nReturn = DecodeBigNum(pDecodedItem);
         break;

#ifndef QCBOR_CONFIG_DISABLE_EXP_AND_MANTISSA
         case CBOR_TAG_DECIMAL_FRACTION:
         case CBOR_TAG_BIGFLOAT:
         // For aggregate tagged types, what goes into pTags is only collected
         // from the surrounding data item, not the contents, so pTags is not
         // passed on here.

         nReturn = QCBORDecode_MantissaAndExponent(me, pDecodedItem);
         break;
#endif /* QCBOR_CONFIG_DISABLE_EXP_AND_MANTISSA */

         case CBOR_TAG_CBOR:
         nReturn = DecodeWrappedCBOR(pDecodedItem);
         break;

         case CBOR_TAG_CBOR_SEQUENCE:
         nReturn = DecodeWrappedCBORSequence(pDecodedItem);
         break;

         case CBOR_TAG_URI:
         nReturn = DecodeURI(pDecodedItem);
         break;

         case CBOR_TAG_B64URL:
         nReturn = DecodeB64URL(pDecodedItem);
         break;

         case CBOR_TAG_B64:
         nReturn = DecodeB64(pDecodedItem);
         break;

         case CBOR_TAG_MIME:
         case CBOR_TAG_BINARY_MIME:
         nReturn = DecodeMIME(pDecodedItem);
         break;

         case CBOR_TAG_REGEX:
         nReturn = DecodeRegex(pDecodedItem);
         break;

         case CBOR_TAG_BIN_UUID:
         nReturn = DecodeUUID(pDecodedItem);
         break;

         case CBOR_TAG_INVALID16:
         // The end of the tag list or no tags
         // Successful exit from the loop.
         goto Done;

         default:
         // A tag that is not understood
         // A successful exit from the loop
         goto Done;

      }
      if(nReturn != QCBOR_SUCCESS) {
         goto Done;
      }
      // A tag was successfully processed, shift it
      // out of the list of tags returned.
      ShiftTags(pDecodedItem);
   }

Done:
   return nReturn;
}


QCBORError
QCBORDecode_GetNext(QCBORDecodeContext *pMe, QCBORItem *pDecodedItem)
{
   QCBORError uErr;
   uErr = QCBORDecode_GetNextTag(pMe, pDecodedItem);
   if(uErr != QCBOR_SUCCESS) {
      pDecodedItem->uDataType  = QCBOR_TYPE_NONE;
      pDecodedItem->uLabelType = QCBOR_TYPE_NONE;
   }
   return uErr;
}


/*
 Public function, see header qcbor/qcbor_decode.h file
 */
void QCBORDecode_VGetNext(QCBORDecodeContext *pMe, QCBORItem *pDecodedItem)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   pMe->uLastError = (uint8_t)QCBORDecode_GetNext(pMe, pDecodedItem);
}


/*
 Public function, see header qcbor/qcbor_decode.h file
 */
QCBORError
QCBORDecode_GetNextWithTags(QCBORDecodeContext *me,
                            QCBORItem *pDecodedItem,
                            QCBORTagListOut *pTags)
{
   QCBORError nReturn;

   nReturn = QCBORDecode_GetNext(me, pDecodedItem);
   if(nReturn != QCBOR_SUCCESS) {
      return nReturn;
   }

   if(pTags != NULL) {
      pTags->uNumUsed = 0;
      // Reverse the order because pTags is reverse of
      // QCBORItem.uTags.
      for(int i = QCBOR_MAX_TAGS_PER_ITEM-1; i >=0 ; i--) {
         if(pDecodedItem->uTags[i] == CBOR_TAG_INVALID16) {
            continue;
         }
         if(pTags->uNumUsed >= pTags->uNumAllocated) {
            return QCBOR_ERR_TOO_MANY_TAGS;
         }
         pTags->puTags[pTags->uNumUsed] = ConvertTag(me,pDecodedItem->uTags[i]);
         pTags->uNumUsed++;
      }
   }

   return QCBOR_SUCCESS;
}


/*
 Decoding items is done in 5 layered functions, one calling the
 next one down. If a layer has no work to do for a particular item
 it returns quickly.

 - QCBORDecode_GetNext, GetNextWithTags -- The top layer processes
 tagged data items, turning them into the local C representation.
 For the most simple it is just associating a QCBOR_TYPE with the data. For
 the complex ones that an aggregate of data items, there is some further
 decoding and a little bit of recursion.

 - QCBORDecode_GetNextMapOrArray - This manages the beginnings and
 ends of maps and arrays. It tracks descending into and ascending
 out of maps/arrays. It processes all breaks that terminate
 indefinite length maps and arrays.

 - GetNext_MapEntry -- This handles the combining of two
 items, the label and the data, that make up a map entry.
 It only does work on maps. It combines the label and data
 items into one labeled item.

 - GetNext_TaggedItem -- This decodes type 6 tagging. It turns the
 tags into bit flags associated with the data item. No actual decoding
 of the contents of the tagged item is performed here.

 - GetNext_FullItem -- This assembles the sub-items that make up
 an indefinte length string into one string item. It uses the
 string allocater to create contiguous space for the item. It
 processes all breaks that are part of indefinite length strings.

 - GetNext_Item -- This decodes the atomic data items in CBOR. Each
 atomic data item has a "major type", an integer "argument" and optionally
 some content. For text and byte strings, the content is the bytes
 that make up the string. These are the smallest data items that are
 considered to be well-formed.  The content may also be other data items in
 the case of aggregate types. They are not handled in this layer.

 Roughly this takes 300 bytes of stack for vars. Need to
 evaluate this more carefully and correctly.

 */


/*
 Public function, see header qcbor/qcbor_decode.h file
 */
bool QCBORDecode_IsTagged(QCBORDecodeContext *me,
                          const QCBORItem   *pItem,
                          uint64_t           uTag)
{
   for(int i = 0; i < QCBOR_MAX_TAGS_PER_ITEM; i++) {
      if(pItem->uTags[i] == CBOR_TAG_INVALID16) {
         break;
      }
      if(ConvertTag(me, pItem->uTags[i]) == uTag) {
         return true;
      }
   }

   return false;
}


/*
 Public function, see header qcbor/qcbor_decode.h file
 */
QCBORError QCBORDecode_Finish(QCBORDecodeContext *me)
{
   QCBORError uReturn = me->uLastError;

   if(uReturn != QCBOR_SUCCESS) {
      goto Done;
   }

   // Error out if all the maps/arrays are not closed out
   if(!DecodeNesting_IsCurrentAtTop(&(me->nesting))) {
      uReturn = QCBOR_ERR_ARRAY_OR_MAP_UNCONSUMED;
      goto Done;
   }

   // Error out if not all the bytes are consumed
   if(UsefulInputBuf_BytesUnconsumed(&(me->InBuf))) {
      uReturn = QCBOR_ERR_EXTRA_BYTES;
   }

Done:
   // Call the destructor for the string allocator if there is one.
   // Always called, even if there are errors; always have to clean up
   StringAllocator_Destruct(&(me->StringAllocator));

   return uReturn;
}


/*
 Public function, see header qcbor/qcbor_decode.h file
*/
// Improvement: make these inline?
uint64_t QCBORDecode_GetNthTag(QCBORDecodeContext *pMe,
                               const QCBORItem    *pItem,
                               uint32_t            uIndex)
{
   if(uIndex >= QCBOR_MAX_TAGS_PER_ITEM) {
      return CBOR_TAG_INVALID64;
   } else {
      return ConvertTag(pMe, pItem->uTags[uIndex]);
   }
}

/*
 Public function, see header qcbor/qcbor_decode.h file
*/
uint64_t QCBORDecode_GetNthTagOfLast(const QCBORDecodeContext *pMe,
                                     uint32_t                  uIndex)
{
   if(uIndex >= QCBOR_MAX_TAGS_PER_ITEM) {
      return CBOR_TAG_INVALID64;
   } else {
      return ConvertTag(pMe, pMe->uLastTags[uIndex]);
   }
}

/*

Decoder errors handled in this file

 - Hit end of input before it was expected while decoding type and
   number QCBOR_ERR_HIT_END

 - negative integer that is too large for C QCBOR_ERR_INT_OVERFLOW

 - Hit end of input while decoding a text or byte string
   QCBOR_ERR_HIT_END

 - Encountered conflicting tags -- e.g., an item is tagged both a date
   string and an epoch date QCBOR_ERR_UNSUPPORTED

 - Encontered an array or mapp that has too many items
   QCBOR_ERR_ARRAY_DECODE_TOO_LONG

 - Encountered array/map nesting that is too deep
   QCBOR_ERR_ARRAY_DECODE_NESTING_TOO_DEEP

 - An epoch date > INT64_MAX or < INT64_MIN was encountered
   QCBOR_ERR_DATE_OVERFLOW

 - The type of a map label is not a string or int
   QCBOR_ERR_MAP_LABEL_TYPE

 - Hit end with arrays or maps still open -- QCBOR_ERR_EXTRA_BYTES

 */




/* ===========================================================================
   MemPool -- BUILT-IN SIMPLE STRING ALLOCATOR

   This implements a simple sting allocator for indefinite length
   strings that can be enabled by calling QCBORDecode_SetMemPool(). It
   implements the function type QCBORStringAllocate and allows easy
   use of it.

   This particular allocator is built-in for convenience. The caller
   can implement their own.  All of this following code will get
   dead-stripped if QCBORDecode_SetMemPool() is not called.

   This is a very primitive memory allocator. It does not track
   individual allocations, only a high-water mark. A free or
   reallocation must be of the last chunk allocated.

   The size of the pool and offset to free memory are packed into the
   first 8 bytes of the memory pool so we don't have to keep them in
   the decode context. Since the address of the pool may not be
   aligned, they have to be packed and unpacked as if they were
   serialized data of the wire or such.

   The sizes packed in are uint32_t to be the same on all CPU types
   and simplify the code.
   ========================================================================== */


static inline int
MemPool_Unpack(const void *pMem, uint32_t *puPoolSize, uint32_t *puFreeOffset)
{
   // Use of UsefulInputBuf is overkill, but it is convenient.
   UsefulInputBuf UIB;

   // Just assume the size here. It was checked during SetUp so
   // the assumption is safe.
   UsefulInputBuf_Init(&UIB, (UsefulBufC){pMem,QCBOR_DECODE_MIN_MEM_POOL_SIZE});
   *puPoolSize     = UsefulInputBuf_GetUint32(&UIB);
   *puFreeOffset   = UsefulInputBuf_GetUint32(&UIB);
   return UsefulInputBuf_GetError(&UIB);
}


static inline int
MemPool_Pack(UsefulBuf Pool, uint32_t uFreeOffset)
{
   // Use of UsefulOutBuf is overkill, but convenient. The
   // length check performed here is useful.
   UsefulOutBuf UOB;

   UsefulOutBuf_Init(&UOB, Pool);
   UsefulOutBuf_AppendUint32(&UOB, (uint32_t)Pool.len); // size of pool
   UsefulOutBuf_AppendUint32(&UOB, uFreeOffset); // first free position
   return UsefulOutBuf_GetError(&UOB);
}


/*
 Internal function for an allocation, reallocation free and destuct.

 Having only one function rather than one each per mode saves space in
 QCBORDecodeContext.

 Code Reviewers: THIS FUNCTION DOES POINTER MATH
 */
static UsefulBuf
MemPool_Function(void *pPool, void *pMem, size_t uNewSize)
{
   UsefulBuf ReturnValue = NULLUsefulBuf;

   uint32_t uPoolSize;
   uint32_t uFreeOffset;

   if(uNewSize > UINT32_MAX) {
      // This allocator is only good up to 4GB.  This check should
      // optimize out if sizeof(size_t) == sizeof(uint32_t)
      goto Done;
   }
   const uint32_t uNewSize32 = (uint32_t)uNewSize;

   if(MemPool_Unpack(pPool, &uPoolSize, &uFreeOffset)) {
      goto Done;
   }

   if(uNewSize) {
      if(pMem) {
         // REALLOCATION MODE
         // Calculate pointer to the end of the memory pool.  It is
         // assumed that pPool + uPoolSize won't wrap around by
         // assuming the caller won't pass a pool buffer in that is
         // not in legitimate memory space.
         const void *pPoolEnd = (uint8_t *)pPool + uPoolSize;

         // Check that the pointer for reallocation is in the range of the
         // pool. This also makes sure that pointer math further down
         // doesn't wrap under or over.
         if(pMem >= pPool && pMem < pPoolEnd) {
            // Offset to start of chunk for reallocation. This won't
            // wrap under because of check that pMem >= pPool.  Cast
            // is safe because the pool is always less than UINT32_MAX
            // because of check in QCBORDecode_SetMemPool().
            const uint32_t uMemOffset = (uint32_t)((uint8_t *)pMem - (uint8_t *)pPool);

            // Check to see if the allocation will fit. uPoolSize -
            // uMemOffset will not wrap under because of check that
            // pMem is in the range of the uPoolSize by check above.
            if(uNewSize <= uPoolSize - uMemOffset) {
               ReturnValue.ptr = pMem;
               ReturnValue.len = uNewSize;

               // Addition won't wrap around over because uNewSize was
               // checked to be sure it is less than the pool size.
               uFreeOffset = uMemOffset + uNewSize32;
            }
         }
      } else {
         // ALLOCATION MODE
         // uPoolSize - uFreeOffset will not underflow because this
         // pool implementation makes sure uFreeOffset is always
         // smaller than uPoolSize through this check here and
         // reallocation case.
         if(uNewSize <= uPoolSize - uFreeOffset) {
            ReturnValue.len = uNewSize;
            ReturnValue.ptr = (uint8_t *)pPool + uFreeOffset;
            uFreeOffset    += (uint32_t)uNewSize;
         }
      }
   } else {
      if(pMem) {
         // FREE MODE
         // Cast is safe because of limit on pool size in
         // QCBORDecode_SetMemPool()
         uFreeOffset = (uint32_t)((uint8_t *)pMem - (uint8_t *)pPool);
      } else {
         // DESTRUCT MODE
         // Nothing to do for this allocator
      }
   }

   UsefulBuf Pool = {pPool, uPoolSize};
   MemPool_Pack(Pool, uFreeOffset);

Done:
   return ReturnValue;
}


/*
 Public function, see header qcbor/qcbor_decode.h file
 */
QCBORError QCBORDecode_SetMemPool(QCBORDecodeContext *pMe,
                                  UsefulBuf Pool,
                                  bool bAllStrings)
{
   // The pool size and free mem offset are packed into the beginning
   // of the pool memory. This compile time check make sure the
   // constant in the header is correct.  This check should optimize
   // down to nothing.
   if(QCBOR_DECODE_MIN_MEM_POOL_SIZE < 2 * sizeof(uint32_t)) {
      return QCBOR_ERR_MEM_POOL_SIZE;
   }

   // The pool size and free offset packed in to the beginning of pool
   // memory are only 32-bits. This check will optimize out on 32-bit
   // machines.
   if(Pool.len > UINT32_MAX) {
      return QCBOR_ERR_MEM_POOL_SIZE;
   }

   // This checks that the pool buffer given is big enough.
   if(MemPool_Pack(Pool, QCBOR_DECODE_MIN_MEM_POOL_SIZE)) {
      return QCBOR_ERR_MEM_POOL_SIZE;
   }

   pMe->StringAllocator.pfAllocator    = MemPool_Function;
   pMe->StringAllocator.pAllocateCxt  = Pool.ptr;
   pMe->bStringAllocateAll             = bAllStrings;

   return QCBOR_SUCCESS;
}



static inline void CopyTags(QCBORDecodeContext *pMe, const QCBORItem *pItem)
{
   memcpy(pMe->uLastTags, pItem->uTags, sizeof(pItem->uTags));
}


/*
 Consume an entire map or array (and do next to
 nothing for non-aggregate types).
 */
static inline QCBORError
ConsumeItem(QCBORDecodeContext *pMe,
            const QCBORItem    *pItemToConsume,
            uint_fast8_t       *puNextNestLevel)
{
   QCBORError uReturn;
   QCBORItem  Item;

   // If it is a map or array, this will tell if it is empty.
   const bool bIsEmpty = (pItemToConsume->uNextNestLevel <= pItemToConsume->uNestingLevel);

   if(QCBORItem_IsMapOrArray(pItemToConsume) && !bIsEmpty) {
      /* There is only real work to do for non-empty maps and arrays */

      /* This works for definite and indefinite length
       * maps and arrays by using the nesting level
       */
      do {
         uReturn = QCBORDecode_GetNext(pMe, &Item);
         if(QCBORDecode_IsUnrecoverableError(uReturn)) {
            goto Done;
         }
      } while(Item.uNextNestLevel >= pItemToConsume->uNextNestLevel);

      if(puNextNestLevel != NULL) {
         *puNextNestLevel = Item.uNextNestLevel;
      }
      uReturn = QCBOR_SUCCESS;

   } else {
      /* item_to_consume is not a map or array */
      if(puNextNestLevel != NULL) {
         /* Just pass the nesting level through */
         *puNextNestLevel = pItemToConsume->uNextNestLevel;
      }
      uReturn = QCBOR_SUCCESS;
   }

Done:
    return uReturn;
}


/* Return true if the labels in Item1 and Item2 are the same.
   Works only for integer and string labels. Returns false
   for any other type. */
static inline bool
MatchLabel(QCBORItem Item1, QCBORItem Item2)
{
   if(Item1.uLabelType == QCBOR_TYPE_INT64) {
      if(Item2.uLabelType == QCBOR_TYPE_INT64 && Item1.label.int64 == Item2.label.int64) {
         return true;
      }
   } else if(Item1.uLabelType == QCBOR_TYPE_TEXT_STRING) {
      if(Item2.uLabelType == QCBOR_TYPE_TEXT_STRING && !UsefulBuf_Compare(Item1.label.string, Item2.label.string)) {
         return true;
      }
   } else if(Item1.uLabelType == QCBOR_TYPE_BYTE_STRING) {
      if(Item2.uLabelType == QCBOR_TYPE_BYTE_STRING && !UsefulBuf_Compare(Item1.label.string, Item2.label.string)) {
         return true;
      }
   } else if(Item1.uLabelType == QCBOR_TYPE_UINT64) {
      if(Item2.uLabelType == QCBOR_TYPE_UINT64 && Item1.label.uint64 == Item2.label.uint64) {
         return true;
      }
   }

   /* Other label types are never matched */
   return false;
}


/*
 Returns true if Item1 and Item2 are the same type
 or if either are of QCBOR_TYPE_ANY.
 */
static inline bool
MatchType(QCBORItem Item1, QCBORItem Item2)
{
   if(Item1.uDataType == Item2.uDataType) {
      return true;
   } else if(Item1.uDataType == QCBOR_TYPE_ANY) {
      return true;
   } else if(Item2.uDataType == QCBOR_TYPE_ANY) {
      return true;
   }
   return false;
}


/**
 @brief Search a map for a set of items.

 @param[in]  pMe           The decode context to search.
 @param[in,out] pItemArray The items to search for and the items found.
 @param[out] puOffset      Byte offset of last item matched.
 @param[in] pCBContext     Context for the not-found item call back.
 @param[in] pfCallback     Function to call on items not matched in pItemArray.

 @retval QCBOR_ERR_NOT_ENTERED Trying to search without having entered a map

 @retval QCBOR_ERR_DUPLICATE_LABEL Duplicate items (items with the same label)
                                   were found for one of the labels being
                                   search for. This duplicate detection is
                                   only performed for items in pItemArray,
                                   not every item in the map.

 @retval QCBOR_ERR_UNEXPECTED_TYPE A label was matched, but the type was
                                   wrong for the matchd label.

 @retval Also errors returned by QCBORDecode_GetNext().

 On input pItemArray contains a list of labels and data types
 of items to be found.

 On output the fully retrieved items are filled in with
 values and such. The label was matched, so it never changes.

 If an item was not found, its data type is set to QCBOR_TYPE_NONE.
 */
// TODO: make this handle indefinite length strings, possibly with
// allocation only when returning the string.
static QCBORError
MapSearch(QCBORDecodeContext *pMe,
          QCBORItem          *pItemArray,
          size_t             *puOffset,
          void               *pCBContext,
          QCBORItemCallback   pfCallback)
{
   QCBORError uReturn;
   uint64_t   uFoundItemBitMap = 0;

   if(pMe->uLastError != QCBOR_SUCCESS) {
      uReturn = pMe->uLastError;
      goto Done2;
   }

   if(!DecodeNesting_IsBoundedType(&(pMe->nesting), QCBOR_TYPE_MAP) &&
      pItemArray->uLabelType != QCBOR_TYPE_NONE) {
      /* QCBOR_TYPE_NONE as first item indicates just looking
         for the end of an array, so don't give error. */
      uReturn = QCBOR_ERR_MAP_NOT_ENTERED;
      goto Done2;
   }

   if(DecodeNesting_IsBoundedEmpty(&(pMe->nesting))) {
      // It is an empty bounded array or map
      if(pItemArray->uLabelType == QCBOR_TYPE_NONE) {
         // Just trying to find the end of the map or array
         pMe->uMapEndOffsetCache = DecodeNesting_GetMapOrArrayStart(&(pMe->nesting));
         uReturn = QCBOR_SUCCESS;
      } else {
         // Nothing is ever found in an empty array or map. All items
         // are marked as not found below.
         uReturn = QCBOR_SUCCESS;
      }
      goto Done2;
   }

   QCBORDecodeNesting SaveNesting;
   DecodeNesting_PrepareForMapSearch(&(pMe->nesting), &SaveNesting);

   /* Reposition to search from the start of the map / array */
   UsefulInputBuf_Seek(&(pMe->InBuf),
                       DecodeNesting_GetMapOrArrayStart(&(pMe->nesting)));

   /*
    Loop over all the items in the map or array. Each item
    could be a map or array, but label matching is only at
    the main level. This handles definite and indefinite
    length maps and arrays. The only reason this is ever
    called on arrays is to find their end position.

    This will always run over all items in order to do
    duplicate detection.

    This will exit with failure if it encounters an
    unrecoverable error, but continue on for recoverable
    errors.

    If a recoverable error occurs on a matched item, then
    that error code is returned.
    */
   const uint8_t uMapNestLevel = DecodeNesting_GetBoundedModeLevel(&(pMe->nesting));
   uint_fast8_t  uNextNestLevel;
   do {
      /* Remember offset of the item because sometimes it has to be returned */
      const size_t uOffset = UsefulInputBuf_Tell(&(pMe->InBuf));

      /* Get the item */
      QCBORItem Item;
      QCBORError uResult = QCBORDecode_GetNextTag(pMe, &Item);
      if(QCBORDecode_IsUnrecoverableError(uResult)) {
         /* Got non-well-formed CBOR so map can't even be decoded. */
         uReturn = uResult;
         goto Done;
      }
      if(uResult == QCBOR_ERR_NO_MORE_ITEMS) {
         // Unexpected end of map or array.
         uReturn = uResult;
         goto Done;
      }

      /* See if item has one of the labels that are of interest */
      bool bMatched = false;
      for(int nIndex = 0; pItemArray[nIndex].uLabelType != QCBOR_TYPE_NONE; nIndex++) {
         if(MatchLabel(Item, pItemArray[nIndex])) {
            /* A label match has been found */
            if(uFoundItemBitMap & (0x01ULL << nIndex)) {
               uReturn = QCBOR_ERR_DUPLICATE_LABEL;
               goto Done;
            }
            /* Also try to match its type */
            if(!MatchType(Item, pItemArray[nIndex])) {
               uReturn = QCBOR_ERR_UNEXPECTED_TYPE;
               goto Done;
            }

            if(uResult != QCBOR_SUCCESS) {
               uReturn = uResult;
               goto Done;
            }

            /* Successful match. Return the item. */
            pItemArray[nIndex] = Item;
            uFoundItemBitMap |= 0x01ULL << nIndex;
            if(puOffset) {
               *puOffset = uOffset;
            }
            bMatched = true;
         }
      }


      if(!bMatched && pfCallback != NULL) {
         /*
          Call the callback on unmatched labels.
          (It is tempting to do duplicate detection here, but that would
          require dynamic memory allocation because the number of labels
          that might be encountered is unbounded.)
         */
         uReturn = (*pfCallback)(pCBContext, &Item);
         if(uReturn != QCBOR_SUCCESS) {
            goto Done;
         }
      }

      /*
       Consume the item whether matched or not. This
       does the work of traversing maps and array and
       everything in them. In this loop only the
       items at the current nesting level are examined
       to match the labels.
       */
      uReturn = ConsumeItem(pMe, &Item, &uNextNestLevel);
      if(uReturn != QCBOR_SUCCESS) {
         goto Done;
      }

   } while (uNextNestLevel >= uMapNestLevel);

   uReturn = QCBOR_SUCCESS;

   const size_t uEndOffset = UsefulInputBuf_Tell(&(pMe->InBuf));

   // Check here makes sure that this won't accidentally be
   // QCBOR_MAP_OFFSET_CACHE_INVALID which is larger than
   // QCBOR_MAX_DECODE_INPUT_SIZE.
   if(uEndOffset >= QCBOR_MAX_DECODE_INPUT_SIZE) {
      uReturn = QCBOR_ERR_INPUT_TOO_LARGE;
      goto Done;
   }
   /* Cast OK because encoded CBOR is limited to UINT32_MAX */
   pMe->uMapEndOffsetCache = (uint32_t)uEndOffset;

 Done:
   DecodeNesting_RestoreFromMapSearch(&(pMe->nesting), &SaveNesting);

 Done2:
   /* For all items not found, set the data and label type to QCBOR_TYPE_NONE */
   for(int i = 0; pItemArray[i].uLabelType != 0; i++) {
      if(!(uFoundItemBitMap & (0x01ULL << i))) {
         pItemArray[i].uDataType  = QCBOR_TYPE_NONE;
         pItemArray[i].uLabelType = QCBOR_TYPE_NONE;
      }
   }

   return uReturn;
}


/*
 Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetItemInMapN(QCBORDecodeContext *pMe,
                               int64_t             nLabel,
                               uint8_t             uQcborType,
                               QCBORItem          *pItem)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   QCBORItem OneItemSeach[2];
   OneItemSeach[0].uLabelType  = QCBOR_TYPE_INT64;
   OneItemSeach[0].label.int64 = nLabel;
   OneItemSeach[0].uDataType   = uQcborType;
   OneItemSeach[1].uLabelType  = QCBOR_TYPE_NONE; // Indicates end of array

   QCBORError uReturn = MapSearch(pMe, OneItemSeach, NULL, NULL, NULL);

   *pItem = OneItemSeach[0];

   if(uReturn != QCBOR_SUCCESS) {
      goto Done;
   }
   if(OneItemSeach[0].uDataType == QCBOR_TYPE_NONE) {
      uReturn = QCBOR_ERR_LABEL_NOT_FOUND;
   }

 Done:
   pMe->uLastError = (uint8_t)uReturn;
}


/*
 Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetItemInMapSZ(QCBORDecodeContext *pMe,
                                const char         *szLabel,
                                uint8_t             uQcborType,
                                QCBORItem          *pItem)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   QCBORItem OneItemSeach[2];
   OneItemSeach[0].uLabelType   = QCBOR_TYPE_TEXT_STRING;
   OneItemSeach[0].label.string = UsefulBuf_FromSZ(szLabel);
   OneItemSeach[0].uDataType    = uQcborType;
   OneItemSeach[1].uLabelType   = QCBOR_TYPE_NONE; // Indicates end of array

   QCBORError uReturn = MapSearch(pMe, OneItemSeach, NULL, NULL, NULL);
   if(uReturn != QCBOR_SUCCESS) {
      goto Done;
   }
   if(OneItemSeach[0].uDataType == QCBOR_TYPE_NONE) {
      uReturn = QCBOR_ERR_LABEL_NOT_FOUND;
      goto Done;
   }

   *pItem = OneItemSeach[0];

Done:
   pMe->uLastError = (uint8_t)uReturn;
}



static QCBORError
CheckTypeList(int uDataType, const uint8_t puTypeList[QCBOR_TAGSPEC_NUM_TYPES])
{
   for(size_t i = 0; i < QCBOR_TAGSPEC_NUM_TYPES; i++) {
      if(uDataType == puTypeList[i]) {
         return QCBOR_SUCCESS;
      }
   }
   return QCBOR_ERR_UNEXPECTED_TYPE;
}


/**
 @param[in] TagSpec  Specification for matching tags.
 @param[in] pItem    The item to check.

 @retval QCBOR_SUCCESS   \c uDataType is allowed by @c TagSpec
 @retval QCBOR_ERR_UNEXPECTED_TYPE \c uDataType is not allowed by @c TagSpec

 The data type must be one of the QCBOR_TYPEs, not the IETF CBOR Registered tag value.
 */
static QCBORError
CheckTagRequirement(const TagSpecification TagSpec, const QCBORItem *pItem)
{
   if(!(TagSpec.uTagRequirement & QCBOR_TAG_REQUIREMENT_ALLOW_ADDITIONAL_TAGS) &&
      pItem->uTags[0] != CBOR_TAG_INVALID16) {
      /* There are tags that QCBOR couldn't process on this item and
       the caller has told us there should not be. */
      return QCBOR_ERR_UNEXPECTED_TYPE;
   }

   const int nTagReq = TagSpec.uTagRequirement & ~QCBOR_TAG_REQUIREMENT_ALLOW_ADDITIONAL_TAGS;
   const int nItemType = pItem->uDataType;

   if(nTagReq == QCBOR_TAG_REQUIREMENT_TAG) {
      // Must match the tag and only the tag
      return CheckTypeList(nItemType, TagSpec.uTaggedTypes);
   }

   QCBORError uReturn = CheckTypeList(nItemType, TagSpec.uAllowedContentTypes);
   if(uReturn == QCBOR_SUCCESS) {
      return QCBOR_SUCCESS;
   }

   if(nTagReq == QCBOR_TAG_REQUIREMENT_NOT_A_TAG) {
      /* Must match the content type and only the content type.
       There was no match just above so it is a fail. */
      return QCBOR_ERR_UNEXPECTED_TYPE;
   }

   /* If here it can match either the tag or the content
    and it hasn't matched the content, so the end
    result is whether it matches the tag. This is
    also the case that the CBOR standard discourages. */

   return CheckTypeList(nItemType, TagSpec.uTaggedTypes);
}



// This could be semi-private if need be
static inline
void QCBORDecode_GetTaggedItemInMapN(QCBORDecodeContext *pMe,
                                     int64_t             nLabel,
                                     TagSpecification    TagSpec,
                                     QCBORItem          *pItem)
{
   QCBORDecode_GetItemInMapN(pMe, nLabel, QCBOR_TYPE_ANY, pItem);
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   pMe->uLastError = (uint8_t)CheckTagRequirement(TagSpec, pItem);
}


// This could be semi-private if need be
static inline
void QCBORDecode_GetTaggedItemInMapSZ(QCBORDecodeContext *pMe,
                                     const char          *szLabel,
                                     TagSpecification    TagSpec,
                                     QCBORItem          *pItem)
{
   QCBORDecode_GetItemInMapSZ(pMe, szLabel, QCBOR_TYPE_ANY, pItem);
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   pMe->uLastError = (uint8_t)CheckTagRequirement(TagSpec, pItem);
}

// Semi-private
void QCBORDecode_GetTaggedStringInMapN(QCBORDecodeContext *pMe,
                                       int64_t             nLabel,
                                       TagSpecification    TagSpec,
                                       UsefulBufC          *pString)
{
   QCBORItem Item;
   QCBORDecode_GetTaggedItemInMapN(pMe, nLabel, TagSpec, &Item);
   if(pMe->uLastError == QCBOR_SUCCESS) {
      *pString = Item.val.string;
   }
}

// Semi-private
void QCBORDecode_GetTaggedStringInMapSZ(QCBORDecodeContext *pMe,
                                        const char *        szLabel,
                                        TagSpecification    TagSpec,
                                        UsefulBufC          *pString)
{
   QCBORItem Item;
   QCBORDecode_GetTaggedItemInMapSZ(pMe, szLabel, TagSpec, &Item);
   if(pMe->uLastError == QCBOR_SUCCESS) {
      *pString = Item.val.string;
   }
}

/*
 Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetItemsInMap(QCBORDecodeContext *pMe, QCBORItem *pItemList)
{
   QCBORError uErr = MapSearch(pMe, pItemList, NULL, NULL, NULL);
   pMe->uLastError = (uint8_t)uErr;
}

/*
 Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetItemsInMapWithCallback(QCBORDecodeContext *pMe,
                                           QCBORItem          *pItemList,
                                           void               *pCallbackCtx,
                                           QCBORItemCallback   pfCB)
{
   QCBORError uErr = MapSearch(pMe, pItemList, NULL, pCallbackCtx, pfCB);
   pMe->uLastError = (uint8_t)uErr;
}


static void SearchAndEnter(QCBORDecodeContext *pMe, QCBORItem pSearch[])
{
   // The first item in pSearch is the one that is to be
   // entered. It should be the only one filled in. Any other
   // will be ignored unless it causes an error.
   if(pMe->uLastError != QCBOR_SUCCESS) {
      // Already in error state; do nothing.
      return;
   }

   size_t uOffset;
   pMe->uLastError = (uint8_t)MapSearch(pMe, pSearch, &uOffset, NULL, NULL);
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   if(pSearch->uDataType == QCBOR_TYPE_NONE) {
      pMe->uLastError = QCBOR_ERR_LABEL_NOT_FOUND;
      return;
   }

   /* Need to get the current pre-order nesting level and cursor to be
      at the map/array about to be entered.

    Also need the current map nesting level and start cursor to
    be at the right place.

    The UsefulInBuf offset could be anywhere, so no assumption is
    made about it.

    No assumption is made about the pre-order nesting level either.

    However the bounded mode nesting level is assumed to be one above
    the map level that is being entered.
    */
   /* Seek to the data item that is the map or array */
   UsefulInputBuf_Seek(&(pMe->InBuf), uOffset);

   DecodeNesting_SetCurrentToBoundedLevel(&(pMe->nesting));

   QCBORDecode_EnterBoundedMapOrArray(pMe, pSearch->uDataType);
}


/*
 Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_EnterMapFromMapN(QCBORDecodeContext *pMe, int64_t nLabel)
{
   QCBORItem OneItemSeach[2];
   OneItemSeach[0].uLabelType  = QCBOR_TYPE_INT64;
   OneItemSeach[0].label.int64 = nLabel;
   OneItemSeach[0].uDataType   = QCBOR_TYPE_MAP;
   OneItemSeach[1].uLabelType  = QCBOR_TYPE_NONE;

   /* The map to enter was found, now finish off entering it. */
   SearchAndEnter(pMe, OneItemSeach);
}


/*
 Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_EnterMapFromMapSZ(QCBORDecodeContext *pMe, const char  *szLabel)
{
   QCBORItem OneItemSeach[2];
   OneItemSeach[0].uLabelType   = QCBOR_TYPE_TEXT_STRING;
   OneItemSeach[0].label.string = UsefulBuf_FromSZ(szLabel);
   OneItemSeach[0].uDataType    = QCBOR_TYPE_MAP;
   OneItemSeach[1].uLabelType   = QCBOR_TYPE_NONE;

   SearchAndEnter(pMe, OneItemSeach);
}

/*
 Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_EnterArrayFromMapN(QCBORDecodeContext *pMe, int64_t nLabel)
{
   QCBORItem OneItemSeach[2];
   OneItemSeach[0].uLabelType  = QCBOR_TYPE_INT64;
   OneItemSeach[0].label.int64 = nLabel;
   OneItemSeach[0].uDataType   = QCBOR_TYPE_ARRAY;
   OneItemSeach[1].uLabelType  = QCBOR_TYPE_NONE;

   SearchAndEnter(pMe, OneItemSeach);
}

/*
 Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_EnterArrayFromMapSZ(QCBORDecodeContext *pMe, const char  *szLabel)
{
   QCBORItem OneItemSeach[2];
   OneItemSeach[0].uLabelType   = QCBOR_TYPE_TEXT_STRING;
   OneItemSeach[0].label.string = UsefulBuf_FromSZ(szLabel);
   OneItemSeach[0].uDataType    = QCBOR_TYPE_ARRAY;
   OneItemSeach[1].uLabelType   = QCBOR_TYPE_NONE;

   SearchAndEnter(pMe, OneItemSeach);
}


// Semi-private function
void QCBORDecode_EnterBoundedMapOrArray(QCBORDecodeContext *pMe, uint8_t uType)
{
    QCBORError uErr;

   /* Must only be called on maps and arrays. */
   if(pMe->uLastError != QCBOR_SUCCESS) {
      // Already in error state; do nothing.
      return;
   }

   /* Get the data item that is the map or array being entered. */
   QCBORItem Item;
   uErr = QCBORDecode_GetNext(pMe, &Item);
   if(uErr != QCBOR_SUCCESS) {
      goto Done;
   }
   if(Item.uDataType != uType) {
      uErr = QCBOR_ERR_UNEXPECTED_TYPE;
      goto Done;
   }

   CopyTags(pMe, &Item);


   const bool bIsEmpty = (Item.uNextNestLevel <= Item.uNestingLevel);
   if(bIsEmpty) {
      if(DecodeNesting_IsCurrentDefiniteLength(&(pMe->nesting))) {
         // Undo decrement done by QCBORDecode_GetNext() so the the
         // the decrement when exiting the map/array works correctly
         pMe->nesting.pCurrent->u.ma.uCountCursor++;
      }
      // Special case to increment nesting level for zero-length maps
      // and arrays entered in bounded mode.
      DecodeNesting_Descend(&(pMe->nesting), uType);
   }

   pMe->uMapEndOffsetCache = QCBOR_MAP_OFFSET_CACHE_INVALID;

   uErr = DecodeNesting_EnterBoundedMapOrArray(&(pMe->nesting), bIsEmpty,
                                               UsefulInputBuf_Tell(&(pMe->InBuf)));

Done:
   pMe->uLastError = (uint8_t)uErr;
}


/*
 This is the common work for exiting a level that is a bounded map,
 array or bstr wrapped CBOR.

 One chunk of work is to set up the pre-order traversal so it is at
 the item just after the bounded map, array or bstr that is being
 exited. This is somewhat complex.

 The other work is to level-up the bounded mode to next higest bounded
 mode or the top level if there isn't one.
 */
static QCBORError
ExitBoundedLevel(QCBORDecodeContext *pMe, uint32_t uEndOffset)
{
   QCBORError uErr;

   /*
    First the pre-order-traversal byte offset is positioned to the
    item just after the bounded mode item that was just consumed.
    */
   UsefulInputBuf_Seek(&(pMe->InBuf), uEndOffset);

   /*
    Next, set the current nesting level to one above the bounded level
    that was just exited.

    DecodeNesting_CheckBoundedType() is always called before this and
    makes sure pCurrentBounded is valid.
    */
   DecodeNesting_LevelUpCurrent(&(pMe->nesting));

   /*
    This does the complex work of leveling up the pre-order traversal
    when the end of a map or array or another bounded level is
    reached.  It may do nothing, or ascend all the way to the top
    level.
    */
   uErr = NestLevelAscender(pMe, false);
   if(uErr != QCBOR_SUCCESS) {
      goto Done;
   }

   /*
    This makes the next highest bounded level the current bounded
    level. If there is no next highest level, then no bounded mode is
    in effect.
    */
   DecodeNesting_LevelUpBounded(&(pMe->nesting));

   pMe->uMapEndOffsetCache = QCBOR_MAP_OFFSET_CACHE_INVALID;

Done:
   return uErr;
}


// Semi-private function
void QCBORDecode_ExitBoundedMapOrArray(QCBORDecodeContext *pMe, uint8_t uType)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      /* Already in error state; do nothing. */
      return;
   }

   QCBORError uErr;

   if(!DecodeNesting_IsBoundedType(&(pMe->nesting), uType)) {
      uErr = QCBOR_ERR_EXIT_MISMATCH;
      goto Done;
   }

   /*
    Have to set the offset to the end of the map/array
    that is being exited. If there is no cached value,
    from previous map search, then do a dummy search.
    */
   if(pMe->uMapEndOffsetCache == QCBOR_MAP_OFFSET_CACHE_INVALID) {
      QCBORItem Dummy;
      Dummy.uLabelType = QCBOR_TYPE_NONE;
      uErr = MapSearch(pMe, &Dummy, NULL, NULL, NULL);
      if(uErr != QCBOR_SUCCESS) {
         goto Done;
      }
   }

   uErr = ExitBoundedLevel(pMe, pMe->uMapEndOffsetCache);

Done:
   pMe->uLastError = (uint8_t)uErr;
}



static QCBORError InternalEnterBstrWrapped(QCBORDecodeContext *pMe,
                                           const QCBORItem    *pItem,
                                           uint8_t             uTagRequirement,
                                           UsefulBufC         *pBstr)
{
   if(pBstr) {
      *pBstr = NULLUsefulBufC;
   }

   if(pMe->uLastError != QCBOR_SUCCESS) {
      // Already in error state; do nothing.
      return pMe->uLastError;
   }

   QCBORError uError = QCBOR_SUCCESS;

   if(pItem->uDataType != QCBOR_TYPE_BYTE_STRING) {
      uError = QCBOR_ERR_UNEXPECTED_TYPE;
      goto Done;;
   }

   const TagSpecification TagSpec =
      {
         uTagRequirement,
         {QBCOR_TYPE_WRAPPED_CBOR, QBCOR_TYPE_WRAPPED_CBOR_SEQUENCE, QCBOR_TYPE_NONE},
         {QCBOR_TYPE_BYTE_STRING, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE}
      };

   uError = CheckTagRequirement(TagSpec, pItem);
   if(uError != QCBOR_SUCCESS) {
      goto Done;
   }

   if(DecodeNesting_IsCurrentDefiniteLength(&(pMe->nesting))) {
      // Reverse the decrement done by GetNext() for the bstr so the
      // increment in NestLevelAscender() called by ExitBoundedLevel()
      // will work right.
      DecodeNesting_ReverseDecrement(&(pMe->nesting));
   }

   if(pBstr) {
      *pBstr = pItem->val.string;
   }

   // This saves the current length of the UsefulInputBuf and then
   // narrows the UsefulInputBuf to start and length of the wrapped
   // CBOR that is being entered.
   //
   // This makes sure the length is less than
   // QCBOR_MAX_DECODE_INPUT_SIZE which is slighly less than
   // UINT32_MAX. The value UINT32_MAX is used as a special indicator
   // value. The checks against QCBOR_MAX_DECODE_INPUT_SIZE also make
   // the casts safe.  uEndOfBstr will always be less than
   // uPreviousLength because of the way UsefulInputBuf works so there
   // is no need to check it.  There is also a range check in the
   // seek.
   //
   // Most of these calls are simple inline accessors so this doesn't
   // amount to much code.
   const size_t uPreviousLength = UsefulInputBuf_GetBufferLength(&(pMe->InBuf));
   if(uPreviousLength >= QCBOR_MAX_DECODE_INPUT_SIZE) {
      uError = QCBOR_ERR_INPUT_TOO_LARGE;
      goto Done;
   }
   const size_t uEndOfBstr = UsefulInputBuf_Tell(&(pMe->InBuf));
   UsefulInputBuf_Seek(&(pMe->InBuf), uEndOfBstr - pItem->val.string.len);
   UsefulInputBuf_SetBufferLength(&(pMe->InBuf), uEndOfBstr);

   uError = DecodeNesting_DescendIntoBstrWrapped(&(pMe->nesting),
                                                 (uint32_t)uPreviousLength,
                                                 (uint32_t)uEndOfBstr);
Done:
   return uError;
}


/*
  Public function, see header qcbor/qcbor_decode.h file
 */
void QCBORDecode_EnterBstrWrapped(QCBORDecodeContext *pMe,
                                  uint8_t             uTagRequirement,
                                  UsefulBufC         *pBstr)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      // Already in error state; do nothing.
      return;
   }

   /* Get the data item that is the map that is being searched */
   QCBORItem Item;
   pMe->uLastError = (uint8_t)QCBORDecode_GetNext(pMe, &Item);
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   pMe->uLastError = (uint8_t)InternalEnterBstrWrapped(pMe,
                                                       &Item,
                                                       uTagRequirement,
                                                       pBstr);
}


/*
  Public function, see header qcbor/qcbor_decode.h file
 */
void QCBORDecode_EnterBstrWrappedFromMapN(QCBORDecodeContext *pMe,
                                          int64_t             nLabel,
                                          uint8_t             uTagRequirement,
                                          UsefulBufC         *pBstr)
{
   QCBORItem Item;
   QCBORDecode_GetItemInMapN(pMe, nLabel, QCBOR_TYPE_ANY, &Item);

   pMe->uLastError = (uint8_t)InternalEnterBstrWrapped(pMe,
                                                       &Item,
                                                       uTagRequirement,
                                                       pBstr);
}


/*
  Public function, see header qcbor/qcbor_decode.h file
 */
void QCBORDecode_EnterBstrWrappedFromMapSZ(QCBORDecodeContext *pMe,
                                           const char         *szLabel,
                                           uint8_t             uTagRequirement,
                                           UsefulBufC         *pBstr)
{
   QCBORItem Item;
   QCBORDecode_GetItemInMapSZ(pMe, szLabel, QCBOR_TYPE_ANY, &Item);

   pMe->uLastError = (uint8_t)InternalEnterBstrWrapped(pMe,
                                                       &Item,
                                                       uTagRequirement,
                                                       pBstr);
}


/*
  Public function, see header qcbor/qcbor_decode.h file
 */
void QCBORDecode_ExitBstrWrapped(QCBORDecodeContext *pMe)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      // Already in error state; do nothing.
      return;
   }

   if(!DecodeNesting_IsBoundedType(&(pMe->nesting), QCBOR_TYPE_BYTE_STRING)) {
      pMe->uLastError = QCBOR_ERR_EXIT_MISMATCH;
      return;
   }

   /*
    Reset the length of the UsefulInputBuf to what it was before
    the bstr wrapped CBOR was entered.
    */
   UsefulInputBuf_SetBufferLength(&(pMe->InBuf),
                               DecodeNesting_GetPreviousBoundedEnd(&(pMe->nesting)));


   QCBORError uErr = ExitBoundedLevel(pMe, DecodeNesting_GetEndOfBstr(&(pMe->nesting)));
   pMe->uLastError = (uint8_t)uErr;
}








static QCBORError
InterpretBool(QCBORDecodeContext *pMe, const QCBORItem *pItem, bool *pBool)
{
   switch(pItem->uDataType) {
      case QCBOR_TYPE_TRUE:
         *pBool = true;
         return QCBOR_SUCCESS;
         break;

      case QCBOR_TYPE_FALSE:
         *pBool = false;
         return QCBOR_SUCCESS;
         break;

      default:
         return QCBOR_ERR_UNEXPECTED_TYPE;
         break;
   }
   CopyTags(pMe, pItem);
}



/*
 Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetBool(QCBORDecodeContext *pMe, bool *pValue)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      // Already in error state, do nothing
      return;
   }

   QCBORError nError;
   QCBORItem  Item;

   nError = QCBORDecode_GetNext(pMe, &Item);
   if(nError != QCBOR_SUCCESS) {
      pMe->uLastError = (uint8_t)nError;
      return;
   }
   pMe->uLastError = (uint8_t)InterpretBool(pMe, &Item, pValue);
}


/*
 Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetBoolInMapN(QCBORDecodeContext *pMe, int64_t nLabel, bool *pValue)
{
   QCBORItem Item;
   QCBORDecode_GetItemInMapN(pMe, nLabel, QCBOR_TYPE_ANY, &Item);

   pMe->uLastError = (uint8_t)InterpretBool(pMe, &Item, pValue);
}


/*
 Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetBoolInMapSZ(QCBORDecodeContext *pMe, const char *szLabel, bool *pValue)
{
   QCBORItem Item;
   QCBORDecode_GetItemInMapSZ(pMe, szLabel, QCBOR_TYPE_ANY, &Item);

   pMe->uLastError = (uint8_t)InterpretBool(pMe, &Item, pValue);
}




static void ProcessEpochDate(QCBORDecodeContext *pMe,
                             QCBORItem           *pItem,
                             uint8_t              uTagRequirement,
                             int64_t             *pnTime)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      // Already in error state, do nothing
      return;
   }

   QCBORError uErr;

   const TagSpecification TagSpec =
   {
      uTagRequirement,
      {QCBOR_TYPE_DATE_EPOCH, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE},
      {QCBOR_TYPE_INT64, QCBOR_TYPE_DOUBLE, QCBOR_TYPE_FLOAT, QCBOR_TYPE_UINT64}
   };

   uErr = CheckTagRequirement(TagSpec, pItem);
   if(uErr != QCBOR_SUCCESS) {
      goto Done;
   }

   if(pItem->uDataType != QCBOR_TYPE_DATE_EPOCH) {
      uErr = DecodeDateEpoch(pItem);
      if(uErr != QCBOR_SUCCESS) {
         goto Done;
      }
   }

   // Save the tags in the last item's tags in the decode context
   // for QCBORDecode_GetNthTagOfLast()
   CopyTags(pMe, pItem);

   *pnTime = pItem->val.epochDate.nSeconds;

Done:
   pMe->uLastError = (uint8_t)uErr;
}


void QCBORDecode_GetEpochDate(QCBORDecodeContext *pMe,
                             uint8_t             uTagRequirement,
                             int64_t            *pnTime)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      // Already in error state, do nothing
      return;
   }

   QCBORItem  Item;
   pMe->uLastError = (uint8_t)QCBORDecode_GetNext(pMe, &Item);

   ProcessEpochDate(pMe, &Item, uTagRequirement, pnTime);
}


void
QCBORDecode_GetEpochDateInMapN(QCBORDecodeContext *pMe,
                               int64_t             nLabel,
                               uint8_t             uTagRequirement,
                               int64_t            *pnTime)
{
   QCBORItem Item;
   QCBORDecode_GetItemInMapN(pMe, nLabel, QCBOR_TYPE_ANY, &Item);
   ProcessEpochDate(pMe, &Item, uTagRequirement, pnTime);
}


void
QCBORDecode_GetEpochDateInMapSZ(QCBORDecodeContext *pMe,
                                const char         *szLabel,
                                uint8_t             uTagRequirement,
                                int64_t            *pnTime)
{
   QCBORItem Item;
   QCBORDecode_GetItemInMapSZ(pMe, szLabel, QCBOR_TYPE_ANY, &Item);
   ProcessEpochDate(pMe, &Item, uTagRequirement, pnTime);
}




void QCBORDecode_GetTaggedStringInternal(QCBORDecodeContext *pMe,
                                         TagSpecification    TagSpec,
                                         UsefulBufC         *pBstr)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      // Already in error state, do nothing
      return;
   }

   QCBORError uError;
   QCBORItem  Item;

   uError = QCBORDecode_GetNext(pMe, &Item);
   if(uError != QCBOR_SUCCESS) {
      pMe->uLastError = (uint8_t)uError;
      return;
   }

   pMe->uLastError = (uint8_t)CheckTagRequirement(TagSpec, &Item);

   if(pMe->uLastError == QCBOR_SUCCESS) {
      *pBstr = Item.val.string;
   } else {
      *pBstr = NULLUsefulBufC;
   }
}




static QCBORError ProcessBigNum(uint8_t          uTagRequirement,
                                const QCBORItem *pItem,
                                UsefulBufC      *pValue,
                                bool            *pbIsNegative)
{
   const TagSpecification TagSpec =
   {
      uTagRequirement,
      {QCBOR_TYPE_POSBIGNUM, QCBOR_TYPE_NEGBIGNUM, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE},
      {QCBOR_TYPE_BYTE_STRING, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE}
   };

   QCBORError uErr = CheckTagRequirement(TagSpec, pItem);
   if(uErr != QCBOR_SUCCESS) {
      return uErr;
   }

   *pValue = pItem->val.string;

   if(pItem->uDataType == QCBOR_TYPE_POSBIGNUM) {
      *pbIsNegative = false;
   } else if(pItem->uDataType == QCBOR_TYPE_NEGBIGNUM) {
      *pbIsNegative = true;
   }

   return QCBOR_SUCCESS;
}


/*
 Public function, see header qcbor/qcbor_decode.h
 */
void QCBORDecode_GetBignum(QCBORDecodeContext *pMe,
                           uint8_t             uTagRequirement,
                           UsefulBufC         *pValue,
                           bool               *pbIsNegative)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      // Already in error state, do nothing
      return;
   }

   QCBORItem  Item;
   QCBORError uError = QCBORDecode_GetNext(pMe, &Item);
   if(uError != QCBOR_SUCCESS) {
      pMe->uLastError = (uint8_t)uError;
      return;
   }

   pMe->uLastError = (uint8_t)ProcessBigNum(uTagRequirement, &Item, pValue, pbIsNegative);
}


/*
 Public function, see header qcbor/qcbor_decode.h
*/
void QCBORDecode_GetBignumInMapN(QCBORDecodeContext *pMe,
                                 int64_t             nLabel,
                                 uint8_t             uTagRequirement,
                                 UsefulBufC         *pValue,
                                 bool               *pbIsNegative)
{
   QCBORItem Item;
   QCBORDecode_GetItemInMapN(pMe, nLabel, QCBOR_TYPE_ANY, &Item);
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   pMe->uLastError = (uint8_t)ProcessBigNum(uTagRequirement, &Item, pValue, pbIsNegative);
}


/*
 Public function, see header qcbor/qcbor_decode.h
*/
void QCBORDecode_GetBignumInMapSZ(QCBORDecodeContext *pMe,
                                  const char         *szLabel,
                                  uint8_t             uTagRequirement,
                                  UsefulBufC         *pValue,
                                  bool               *pbIsNegative)
{
   QCBORItem Item;
   QCBORDecode_GetItemInMapSZ(pMe, szLabel, QCBOR_TYPE_ANY, &Item);
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   pMe->uLastError = (uint8_t)ProcessBigNum(uTagRequirement, &Item, pValue, pbIsNegative);
}




// Semi private
QCBORError QCBORDecode_GetMIMEInternal(uint8_t     uTagRequirement,
                                       const       QCBORItem *pItem,
                                       UsefulBufC *pMessage,
                                       bool       *pbIsTag257)
{
   const TagSpecification TagSpecText =
      {
         uTagRequirement,
         {QCBOR_TYPE_MIME, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE},
         {QCBOR_TYPE_TEXT_STRING, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE}
      };
   const TagSpecification TagSpecBinary =
      {
         uTagRequirement,
         {QCBOR_TYPE_BINARY_MIME, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE},
         {QCBOR_TYPE_BYTE_STRING, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE}
      };

   QCBORError uReturn;

   if(CheckTagRequirement(TagSpecText, pItem) == QCBOR_SUCCESS) {
      *pMessage = pItem->val.string;
      if(pbIsTag257 != NULL) {
         *pbIsTag257 = false;
      }
      uReturn = QCBOR_SUCCESS;
   } else if(CheckTagRequirement(TagSpecBinary, pItem) == QCBOR_SUCCESS) {
      *pMessage = pItem->val.string;
      if(pbIsTag257 != NULL) {
         *pbIsTag257 = true;
      }
      uReturn = QCBOR_SUCCESS;

   } else {
      uReturn = QCBOR_ERR_UNEXPECTED_TYPE;
   }

   return uReturn;
}

// Improvement: add methods for wrapped CBOR, a simple alternate
// to EnterBstrWrapped




#ifndef QCBOR_CONFIG_DISABLE_EXP_AND_MANTISSA

typedef QCBORError (*fExponentiator)(uint64_t uMantissa, int64_t nExponent, uint64_t *puResult);


// The exponentiator that works on only positive numbers
static QCBORError
Exponentitate10(uint64_t uMantissa, int64_t nExponent, uint64_t *puResult)
{
   uint64_t uResult = uMantissa;

   if(uResult != 0) {
      /* This loop will run a maximum of 19 times because
       * UINT64_MAX < 10 ^^ 19. More than that will cause
       * exit with the overflow error
       */
      for(; nExponent > 0; nExponent--) {
         if(uResult > UINT64_MAX / 10) {
            return QCBOR_ERR_CONVERSION_UNDER_OVER_FLOW; // Error overflow
         }
         uResult = uResult * 10;
      }

      for(; nExponent < 0; nExponent++) {
         uResult = uResult / 10;
         if(uResult == 0) {
            return QCBOR_ERR_CONVERSION_UNDER_OVER_FLOW; // Underflow error
         }
      }
   }
   /* else, mantissa is zero so this returns zero */

   *puResult = uResult;

   return QCBOR_SUCCESS;
}


// The exponentiator that works on only positive numbers
static QCBORError
Exponentitate2(uint64_t uMantissa, int64_t nExponent, uint64_t *puResult)
{
   uint64_t uResult;

   uResult = uMantissa;

   /* This loop will run a maximum of 64 times because
    * INT64_MAX < 2^31. More than that will cause
    * exit with the overflow error
    */
   while(nExponent > 0) {
      if(uResult > UINT64_MAX >> 1) {
         return QCBOR_ERR_CONVERSION_UNDER_OVER_FLOW; // Error overflow
      }
      uResult = uResult << 1;
      nExponent--;
   }

   while(nExponent < 0 ) {
      if(uResult == 0) {
         return QCBOR_ERR_CONVERSION_UNDER_OVER_FLOW; // Underflow error
      }
      uResult = uResult >> 1;
      nExponent++;
   }

   *puResult = uResult;

   return QCBOR_SUCCESS;
}


/*
 Compute value with signed mantissa and signed result. Works with
 exponent of 2 or 10 based on exponentiator.
 */
static inline QCBORError ExponentiateNN(int64_t       nMantissa,
                                        int64_t       nExponent,
                                        int64_t       *pnResult,
                                        fExponentiator pfExp)
{
   uint64_t uResult;

   // Take the absolute value of the mantissa and convert to unsigned.
   // Improvement: this should be possible in one instruction
   uint64_t uMantissa = nMantissa > 0 ? (uint64_t)nMantissa : (uint64_t)-nMantissa;

   // Do the exponentiation of the positive mantissa
   QCBORError uReturn = (*pfExp)(uMantissa, nExponent, &uResult);
   if(uReturn) {
      return uReturn;
   }


   /* (uint64_t)INT64_MAX+1 is used to represent the absolute value
    of INT64_MIN. This assumes two's compliment representation where
    INT64_MIN is one increment farther from 0 than INT64_MAX.
    Trying to write -INT64_MIN doesn't work to get this because the
    compiler tries to work with an int64_t which can't represent
    -INT64_MIN.
    */
   uint64_t uMax = nMantissa > 0 ? INT64_MAX : (uint64_t)INT64_MAX+1;

   // Error out if too large
   if(uResult > uMax) {
      return QCBOR_ERR_CONVERSION_UNDER_OVER_FLOW;
   }

   // Casts are safe because of checks above
   *pnResult = nMantissa > 0 ? (int64_t)uResult : -(int64_t)uResult;

   return QCBOR_SUCCESS;
}


/*
 Compute value with signed mantissa and unsigned result. Works with
 exponent of 2 or 10 based on exponentiator.
 */
static inline QCBORError ExponentitateNU(int64_t       nMantissa,
                                         int64_t       nExponent,
                                         uint64_t      *puResult,
                                         fExponentiator pfExp)
{
   if(nMantissa < 0) {
      return QCBOR_ERR_NUMBER_SIGN_CONVERSION;
   }

   // Cast to unsigned is OK because of check for negative
   // Cast to unsigned is OK because UINT64_MAX > INT64_MAX
   // Exponentiation is straight forward
   return (*pfExp)((uint64_t)nMantissa, nExponent, puResult);
}


/*
 Compute value with signed mantissa and unsigned result. Works with
 exponent of 2 or 10 based on exponentiator.
 */
static inline QCBORError ExponentitateUU(uint64_t       uMantissa,
                                         int64_t        nExponent,
                                         uint64_t      *puResult,
                                         fExponentiator pfExp)
{
   return (*pfExp)(uMantissa, nExponent, puResult);
}

#endif /* QCBOR_CONFIG_DISABLE_EXP_AND_MANTISSA */





static QCBORError ConvertBigNumToUnsigned(const UsefulBufC BigNum, uint64_t uMax, uint64_t *pResult)
{
   uint64_t uResult;

   uResult = 0;
   const uint8_t *pByte = BigNum.ptr;
   size_t uLen = BigNum.len;
   while(uLen--) {
      if(uResult > (uMax >> 8)) {
         return QCBOR_ERR_CONVERSION_UNDER_OVER_FLOW;
      }
      uResult = (uResult << 8) + *pByte++;
   }

   *pResult = uResult;
   return QCBOR_SUCCESS;
}


static inline QCBORError ConvertPositiveBigNumToUnsigned(const UsefulBufC BigNum, uint64_t *pResult)
{
   return ConvertBigNumToUnsigned(BigNum, UINT64_MAX, pResult);
}


static inline QCBORError ConvertPositiveBigNumToSigned(const UsefulBufC BigNum, int64_t *pResult)
{
   uint64_t uResult;
   QCBORError uError =  ConvertBigNumToUnsigned(BigNum, INT64_MAX, &uResult);
   if(uError) {
      return uError;
   }
   /* Cast is safe because ConvertBigNum is told to limit to INT64_MAX */
   *pResult = (int64_t)uResult;
   return QCBOR_SUCCESS;
}


static inline QCBORError ConvertNegativeBigNumToSigned(const UsefulBufC BigNum, int64_t *pnResult)
{
   uint64_t uResult;
   /* The negative integer furthest from zero for a C int64_t is
    INT64_MIN which is expressed as -INT64_MAX - 1. The value of a
    negative number in CBOR is computed as -n - 1 where n is the
    encoded integer, where n is what is in the variable BigNum. When
    converting BigNum to a uint64_t, the maximum value is thus
    INT64_MAX, so that when it -n - 1 is applied to it the result will
    never be further from 0 than INT64_MIN.

       -n - 1 <= INT64_MIN.
       -n - 1 <= -INT64_MAX - 1
        n     <= INT64_MAX.
    */
   QCBORError uError = ConvertBigNumToUnsigned(BigNum, INT64_MAX, &uResult);
   if(uError != QCBOR_SUCCESS) {
      return uError;
   }

   /// Now apply -n - 1. The cast is safe because
   // ConvertBigNumToUnsigned() is limited to INT64_MAX which does fit
   // is the largest positive integer that an int64_t can
   // represent. */
   *pnResult =  -(int64_t)uResult - 1;

   return QCBOR_SUCCESS;
}





/*
Convert a integers and floats to an int64_t.

\param[in] uConvertTypes  Bit mask list of conversion options.

\retval QCBOR_ERR_UNEXPECTED_TYPE  Conversion, possible, but not requested
                                   in uConvertTypes.

\retval QCBOR_ERR_UNEXPECTED_TYPE  Of a type that can't be converted

\retval QCBOR_ERR_CONVERSION_UNDER_OVER_FLOW  Conversion result is too large
                                              or too small.
*/
static QCBORError
ConvertInt64(const QCBORItem *pItem, uint32_t uConvertTypes, int64_t *pnValue)
{
   switch(pItem->uDataType) {
      case QCBOR_TYPE_FLOAT:
      case QCBOR_TYPE_DOUBLE:
#ifndef QCBOR_DISABLE_FLOAT_HW_USE
         if(uConvertTypes & QCBOR_CONVERT_TYPE_FLOAT) {
            /* https://pubs.opengroup.org/onlinepubs/009695399/functions/llround.html
             http://www.cplusplus.com/reference/cmath/llround/
             */
            // Not interested in FE_INEXACT
            feclearexcept(FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW|FE_DIVBYZERO);
            if(pItem->uDataType == QCBOR_TYPE_DOUBLE) {
               *pnValue = llround(pItem->val.dfnum);
            } else {
               *pnValue = lroundf(pItem->val.fnum);
            }
            if(fetestexcept(FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW|FE_DIVBYZERO)) {
               // llround() shouldn't result in divide by zero, but catch
               // it here in case it unexpectedly does.  Don't try to
               // distinguish between the various exceptions because it seems
               // they vary by CPU, compiler and OS.
               return QCBOR_ERR_FLOAT_EXCEPTION;
            }
         } else {
            return  QCBOR_ERR_UNEXPECTED_TYPE;
         }
#else
         return QCBOR_ERR_HW_FLOAT_DISABLED;
#endif /* QCBOR_DISABLE_FLOAT_HW_USE */
         break;

      case QCBOR_TYPE_INT64:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_XINT64) {
            *pnValue = pItem->val.int64;
         } else {
            return  QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

      case QCBOR_TYPE_UINT64:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_XINT64) {
            if(pItem->val.uint64 < INT64_MAX) {
               *pnValue = pItem->val.int64;
            } else {
               return QCBOR_ERR_CONVERSION_UNDER_OVER_FLOW;
            }
         } else {
            return  QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

      default:
         return  QCBOR_ERR_UNEXPECTED_TYPE;
   }
   return QCBOR_SUCCESS;
}


void QCBORDecode_GetInt64ConvertInternal(QCBORDecodeContext *pMe,
                                         uint32_t            uConvertTypes,
                                         int64_t            *pnValue,
                                         QCBORItem          *pItem)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   QCBORItem Item;
   QCBORError uError = QCBORDecode_GetNext(pMe, &Item);
   if(uError) {
      pMe->uLastError = (uint8_t)uError;
      return;
   }

   if(pItem) {
      *pItem = Item;
   }

   pMe->uLastError = (uint8_t)ConvertInt64(&Item, uConvertTypes, pnValue);
}


void QCBORDecode_GetInt64ConvertInternalInMapN(QCBORDecodeContext *pMe,
                                               int64_t             nLabel,
                                               uint32_t            uConvertTypes,
                                               int64_t            *pnValue,
                                               QCBORItem          *pItem)
{
   QCBORDecode_GetItemInMapN(pMe, nLabel, QCBOR_TYPE_ANY, pItem);
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   pMe->uLastError = (uint8_t)ConvertInt64(pItem, uConvertTypes, pnValue);
}


void QCBORDecode_GetInt64ConvertInternalInMapSZ(QCBORDecodeContext *pMe,
                                               const char *         szLabel,
                                               uint32_t             uConvertTypes,
                                               int64_t             *pnValue,
                                               QCBORItem           *pItem)
{
   QCBORDecode_GetItemInMapSZ(pMe, szLabel, QCBOR_TYPE_ANY, pItem);
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   pMe->uLastError = (uint8_t)ConvertInt64(pItem, uConvertTypes, pnValue);
}


/*
 Convert a large variety of integer types to an int64_t.

 \param[in] uConvertTypes  Bit mask list of conversion options.

 \retval QCBOR_ERR_UNEXPECTED_TYPE  Conversion, possible, but not requested
                                    in uConvertTypes.

 \retval QCBOR_ERR_UNEXPECTED_TYPE  Of a type that can't be converted

 \retval QCBOR_ERR_CONVERSION_UNDER_OVER_FLOW  Conversion result is too large
                                               or too small.
 */
static QCBORError
Int64ConvertAll(const QCBORItem *pItem, uint32_t uConvertTypes, int64_t *pnValue)
{
   switch(pItem->uDataType) {

      case QCBOR_TYPE_POSBIGNUM:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_BIG_NUM) {
            return ConvertPositiveBigNumToSigned(pItem->val.bigNum, pnValue);
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

      case QCBOR_TYPE_NEGBIGNUM:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_BIG_NUM) {
            return ConvertNegativeBigNumToSigned(pItem->val.bigNum, pnValue);
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

#ifndef QCBOR_CONFIG_DISABLE_EXP_AND_MANTISSA
      case QCBOR_TYPE_DECIMAL_FRACTION:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_DECIMAL_FRACTION) {
            return ExponentiateNN(pItem->val.expAndMantissa.Mantissa.nInt,
                                  pItem->val.expAndMantissa.nExponent,
                                  pnValue,
                                 &Exponentitate10);
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

      case QCBOR_TYPE_BIGFLOAT:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_BIGFLOAT) {
            return ExponentiateNN(pItem->val.expAndMantissa.Mantissa.nInt,
                                  pItem->val.expAndMantissa.nExponent,
                                  pnValue,
                                  Exponentitate2);
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

      case QCBOR_TYPE_DECIMAL_FRACTION_POS_BIGNUM:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_DECIMAL_FRACTION) {
            int64_t    nMantissa;
            QCBORError uErr;
            uErr = ConvertPositiveBigNumToSigned(pItem->val.expAndMantissa.Mantissa.bigNum, &nMantissa);
            if(uErr) {
               return uErr;
            }
            return ExponentiateNN(nMantissa,
                                  pItem->val.expAndMantissa.nExponent,
                                  pnValue,
                                  Exponentitate10);
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

      case QCBOR_TYPE_DECIMAL_FRACTION_NEG_BIGNUM:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_DECIMAL_FRACTION) {
            int64_t    nMantissa;
            QCBORError uErr;
            uErr = ConvertNegativeBigNumToSigned(pItem->val.expAndMantissa.Mantissa.bigNum, &nMantissa);
            if(uErr) {
               return uErr;
            }
            return ExponentiateNN(nMantissa,
                                  pItem->val.expAndMantissa.nExponent,
                                  pnValue,
                                  Exponentitate10);
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

      case QCBOR_TYPE_BIGFLOAT_POS_BIGNUM:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_DECIMAL_FRACTION) {
            int64_t    nMantissa;
            QCBORError uErr;
            uErr = ConvertPositiveBigNumToSigned(pItem->val.expAndMantissa.Mantissa.bigNum, &nMantissa);
            if(uErr) {
               return uErr;
            }
            return ExponentiateNN(nMantissa,
                                  pItem->val.expAndMantissa.nExponent,
                                  pnValue,
                                  Exponentitate2);
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

      case QCBOR_TYPE_BIGFLOAT_NEG_BIGNUM:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_DECIMAL_FRACTION) {
            int64_t    nMantissa;
            QCBORError uErr;
            uErr = ConvertNegativeBigNumToSigned(pItem->val.expAndMantissa.Mantissa.bigNum, &nMantissa);
            if(uErr) {
               return uErr;
            }
            return ExponentiateNN(nMantissa,
                                  pItem->val.expAndMantissa.nExponent,
                                  pnValue,
                                  Exponentitate2);
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;
#endif /* QCBOR_CONFIG_DISABLE_EXP_AND_MANTISSA */


      default:
         return QCBOR_ERR_UNEXPECTED_TYPE;   }
}


/*
 Public function, see header qcbor/qcbor_decode.h file
 */
void QCBORDecode_GetInt64ConvertAll(QCBORDecodeContext *pMe, uint32_t uConvertTypes, int64_t *pnValue)
{
   QCBORItem Item;

   QCBORDecode_GetInt64ConvertInternal(pMe, uConvertTypes, pnValue, &Item);

   if(pMe->uLastError == QCBOR_SUCCESS) {
      // The above conversion succeeded
      return;
   }

   if(pMe->uLastError != QCBOR_ERR_UNEXPECTED_TYPE) {
      // The above conversion failed in a way that code below can't correct
      return;
   }

   pMe->uLastError = (uint8_t)Int64ConvertAll(&Item, uConvertTypes, pnValue);
}


/*
Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetInt64ConvertAllInMapN(QCBORDecodeContext *pMe,
                                          int64_t             nLabel,
                                          uint32_t            uConvertTypes,
                                          int64_t            *pnValue)
{
   QCBORItem Item;

   QCBORDecode_GetInt64ConvertInternalInMapN(pMe,
                                             nLabel,
                                             uConvertTypes,
                                             pnValue,
                                             &Item);

   if(pMe->uLastError == QCBOR_SUCCESS) {
      // The above conversion succeeded
      return;
   }

   if(pMe->uLastError != QCBOR_ERR_UNEXPECTED_TYPE) {
      // The above conversion failed in a way that code below can't correct
      return;
   }

   pMe->uLastError = (uint8_t)Int64ConvertAll(&Item, uConvertTypes, pnValue);
}


/*
Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetInt64ConvertAllInMapSZ(QCBORDecodeContext *pMe,
                                           const char         *szLabel,
                                           uint32_t            uConvertTypes,
                                           int64_t            *pnValue)
{
   QCBORItem Item;
   QCBORDecode_GetInt64ConvertInternalInMapSZ(pMe,
                                              szLabel,
                                              uConvertTypes,
                                              pnValue,
                                              &Item);

   if(pMe->uLastError == QCBOR_SUCCESS) {
      // The above conversion succeeded
      return;
   }

   if(pMe->uLastError != QCBOR_ERR_UNEXPECTED_TYPE) {
      // The above conversion failed in a way that code below can't correct
      return;
   }

   pMe->uLastError = (uint8_t)Int64ConvertAll(&Item, uConvertTypes, pnValue);
}


static QCBORError ConvertUInt64(const QCBORItem *pItem, uint32_t uConvertTypes, uint64_t *puValue)
{
   switch(pItem->uDataType) {
      case QCBOR_TYPE_DOUBLE:
      case QCBOR_TYPE_FLOAT:
#ifndef QCBOR_DISABLE_FLOAT_HW_USE
         if(uConvertTypes & QCBOR_CONVERT_TYPE_FLOAT) {
            // Can't use llround here because it will not convert values
            // greater than INT64_MAX and less than UINT64_MAX that
            // need to be converted so it is more complicated.
            feclearexcept(FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW|FE_DIVBYZERO);
            if(pItem->uDataType == QCBOR_TYPE_DOUBLE) {
               if(isnan(pItem->val.dfnum)) {
                  return QCBOR_ERR_FLOAT_EXCEPTION;
               } else if(pItem->val.dfnum < 0) {
                  return QCBOR_ERR_NUMBER_SIGN_CONVERSION;
               } else {
                  double dRounded = round(pItem->val.dfnum);
                  // See discussion in DecodeDateEpoch() for
                  // explanation of - 0x7ff
                  if(dRounded > (double)(UINT64_MAX- 0x7ff)) {
                     return QCBOR_ERR_CONVERSION_UNDER_OVER_FLOW;
                  }
                  *puValue = (uint64_t)dRounded;
               }
            } else {
               if(isnan(pItem->val.fnum)) {
                  return QCBOR_ERR_FLOAT_EXCEPTION;
               } else if(pItem->val.fnum < 0) {
                  return QCBOR_ERR_NUMBER_SIGN_CONVERSION;
               } else {
                  float fRounded = roundf(pItem->val.fnum);
                  // See discussion in DecodeDateEpoch() for
                  // explanation of - 0x7ff
                  if(fRounded > (float)(UINT64_MAX- 0x7ff)) {
                     return QCBOR_ERR_CONVERSION_UNDER_OVER_FLOW;
                  }
                  *puValue = (uint64_t)fRounded;
               }
            }
            if(fetestexcept(FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW|FE_DIVBYZERO)) {
               // round() and roundf() shouldn't result in exceptions here, but
               // catch them to be robust and thorough. Don't try to
               // distinguish between the various exceptions because it seems
               // they vary by CPU, compiler and OS.
               return QCBOR_ERR_FLOAT_EXCEPTION;
            }

         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
#else
         return QCBOR_ERR_HW_FLOAT_DISABLED;
#endif /* QCBOR_DISABLE_FLOAT_HW_USE */
         break;

      case QCBOR_TYPE_INT64:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_XINT64) {
            if(pItem->val.int64 >= 0) {
               *puValue = (uint64_t)pItem->val.int64;
            } else {
               return QCBOR_ERR_NUMBER_SIGN_CONVERSION;
            }
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

      case QCBOR_TYPE_UINT64:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_XINT64) {
            *puValue =  pItem->val.uint64;
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

      default:
         return QCBOR_ERR_UNEXPECTED_TYPE;
   }

   return QCBOR_SUCCESS;
}


void QCBORDecode_GetUInt64ConvertInternal(QCBORDecodeContext *pMe,
                                          uint32_t uConvertTypes,
                                          uint64_t *puValue,
                                          QCBORItem *pItem)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   QCBORItem Item;

   QCBORError uError = QCBORDecode_GetNext(pMe, &Item);
   if(uError) {
      pMe->uLastError = (uint8_t)uError;
      return;
   }

   if(pItem) {
      *pItem = Item;
   }

   pMe->uLastError = (uint8_t)ConvertUInt64(&Item, uConvertTypes, puValue);
}


void QCBORDecode_GetUInt64ConvertInternalInMapN(QCBORDecodeContext *pMe,
                                               int64_t             nLabel,
                                               uint32_t            uConvertTypes,
                                               uint64_t            *puValue,
                                               QCBORItem          *pItem)
{
   QCBORDecode_GetItemInMapN(pMe, nLabel, QCBOR_TYPE_ANY, pItem);
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   pMe->uLastError = (uint8_t)ConvertUInt64(pItem, uConvertTypes, puValue);
}


void QCBORDecode_GetUInt64ConvertInternalInMapSZ(QCBORDecodeContext *pMe,
                                               const char *         szLabel,
                                               uint32_t             uConvertTypes,
                                               uint64_t             *puValue,
                                               QCBORItem           *pItem)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   QCBORDecode_GetItemInMapSZ(pMe, szLabel, QCBOR_TYPE_ANY, pItem);
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   pMe->uLastError = (uint8_t)ConvertUInt64(pItem, uConvertTypes, puValue);
}


/*
 Public function, see header qcbor/qcbor_decode.h file
*/
static QCBORError
UInt64ConvertAll(const QCBORItem *pItem, uint32_t uConvertTypes, uint64_t *puValue)
{
   switch(pItem->uDataType) {

      case QCBOR_TYPE_POSBIGNUM:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_BIG_NUM) {
            return ConvertPositiveBigNumToUnsigned(pItem->val.bigNum, puValue);
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

      case QCBOR_TYPE_NEGBIGNUM:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_BIG_NUM) {
            return QCBOR_ERR_NUMBER_SIGN_CONVERSION;
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

#ifndef QCBOR_CONFIG_DISABLE_EXP_AND_MANTISSA

      case QCBOR_TYPE_DECIMAL_FRACTION:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_DECIMAL_FRACTION) {
            return ExponentitateNU(pItem->val.expAndMantissa.Mantissa.nInt,
                                   pItem->val.expAndMantissa.nExponent,
                                   puValue,
                                   Exponentitate10);
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

      case QCBOR_TYPE_BIGFLOAT:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_BIGFLOAT) {
            return ExponentitateNU(pItem->val.expAndMantissa.Mantissa.nInt,
                                   pItem->val.expAndMantissa.nExponent,
                                   puValue,
                                   Exponentitate2);
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

      case QCBOR_TYPE_DECIMAL_FRACTION_POS_BIGNUM:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_DECIMAL_FRACTION) {
            uint64_t   uMantissa;
            QCBORError uErr;
            uErr = ConvertPositiveBigNumToUnsigned(pItem->val.expAndMantissa.Mantissa.bigNum, &uMantissa);
            if(uErr != QCBOR_SUCCESS) {
               return uErr;
            }
            return ExponentitateUU(uMantissa,
                                   pItem->val.expAndMantissa.nExponent,
                                   puValue,
                                   Exponentitate10);
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

      case QCBOR_TYPE_DECIMAL_FRACTION_NEG_BIGNUM:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_DECIMAL_FRACTION) {
            return QCBOR_ERR_NUMBER_SIGN_CONVERSION;
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

      case QCBOR_TYPE_BIGFLOAT_POS_BIGNUM:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_DECIMAL_FRACTION) {
            uint64_t   uMantissa;
            QCBORError uErr;
            uErr =  ConvertPositiveBigNumToUnsigned(pItem->val.expAndMantissa.Mantissa.bigNum, &uMantissa);
            if(uErr != QCBOR_SUCCESS) {
               return uErr;
            }
            return ExponentitateUU(uMantissa,
                                   pItem->val.expAndMantissa.nExponent,
                                   puValue,
                                   Exponentitate2);
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

      case QCBOR_TYPE_BIGFLOAT_NEG_BIGNUM:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_DECIMAL_FRACTION) {
            return QCBOR_ERR_NUMBER_SIGN_CONVERSION;
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;
#endif
      default:
         return QCBOR_ERR_UNEXPECTED_TYPE;
   }
}


/*
  Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetUInt64ConvertAll(QCBORDecodeContext *pMe, uint32_t uConvertTypes, uint64_t *puValue)
{
   QCBORItem Item;

   QCBORDecode_GetUInt64ConvertInternal(pMe, uConvertTypes, puValue, &Item);

   if(pMe->uLastError == QCBOR_SUCCESS) {
      // The above conversion succeeded
      return;
   }

   if(pMe->uLastError != QCBOR_ERR_UNEXPECTED_TYPE) {
      // The above conversion failed in a way that code below can't correct
      return;
   }

   pMe->uLastError = (uint8_t)UInt64ConvertAll(&Item, uConvertTypes, puValue);
}


/*
  Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetUInt64ConvertAllInMapN(QCBORDecodeContext *pMe,
                                           int64_t             nLabel,
                                           uint32_t            uConvertTypes,
                                           uint64_t           *puValue)
{
   QCBORItem Item;

   QCBORDecode_GetUInt64ConvertInternalInMapN(pMe,
                                              nLabel,
                                              uConvertTypes,
                                              puValue,
                                              &Item);

   if(pMe->uLastError == QCBOR_SUCCESS) {
      // The above conversion succeeded
      return;
   }

   if(pMe->uLastError != QCBOR_ERR_UNEXPECTED_TYPE) {
      // The above conversion failed in a way that code below can't correct
      return;
   }

   pMe->uLastError = (uint8_t)UInt64ConvertAll(&Item, uConvertTypes, puValue);
}


/*
  Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetUInt64ConvertAllInMapSZ(QCBORDecodeContext *pMe,
                                            const char         *szLabel,
                                            uint32_t            uConvertTypes,
                                            uint64_t           *puValue)
{
   QCBORItem Item;
   QCBORDecode_GetUInt64ConvertInternalInMapSZ(pMe,
                                               szLabel,
                                               uConvertTypes,
                                               puValue,
                                               &Item);

   if(pMe->uLastError == QCBOR_SUCCESS) {
      // The above conversion succeeded
      return;
   }

   if(pMe->uLastError != QCBOR_ERR_UNEXPECTED_TYPE) {
      // The above conversion failed in a way that code below can't correct
      return;
   }

   pMe->uLastError = (uint8_t)UInt64ConvertAll(&Item, uConvertTypes, puValue);
}


static QCBORError ConvertDouble(const QCBORItem *pItem,
                                uint32_t         uConvertTypes,
                                double          *pdValue)
{
   switch(pItem->uDataType) {
      case QCBOR_TYPE_FLOAT:
#ifndef QCBOR_DISABLE_FLOAT_HW_USE
         if(uConvertTypes & QCBOR_CONVERT_TYPE_FLOAT) {
            if(uConvertTypes & QCBOR_CONVERT_TYPE_FLOAT) {
               // Simple cast does the job.
               *pdValue = (double)pItem->val.fnum;
            } else {
               return QCBOR_ERR_UNEXPECTED_TYPE;
            }
         }
#else
         return QCBOR_ERR_HW_FLOAT_DISABLED;
#endif
         break;

      case QCBOR_TYPE_DOUBLE:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_FLOAT) {
            if(uConvertTypes & QCBOR_CONVERT_TYPE_FLOAT) {
               *pdValue = pItem->val.dfnum;
            } else {
               return QCBOR_ERR_UNEXPECTED_TYPE;
            }
         }
         break;

      case QCBOR_TYPE_INT64:
#ifndef QCBOR_DISABLE_FLOAT_HW_USE
         if(uConvertTypes & QCBOR_CONVERT_TYPE_XINT64) {
            // A simple cast seems to do the job with no worry of exceptions.
            // There will be precision loss for some values.
            *pdValue = (double)pItem->val.int64;

         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
#else
         return QCBOR_ERR_HW_FLOAT_DISABLED;
#endif /* QCBOR_DISABLE_FLOAT_HW_USE */
         break;

      case QCBOR_TYPE_UINT64:
#ifndef QCBOR_DISABLE_FLOAT_HW_USE
         if(uConvertTypes & QCBOR_CONVERT_TYPE_XINT64) {
            // A simple cast seems to do the job with no worry of exceptions.
            // There will be precision loss for some values.
            *pdValue = (double)pItem->val.uint64;
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;
#else
         return QCBOR_ERR_HW_FLOAT_DISABLED;
#endif /* QCBOR_DISABLE_FLOAT_HW_USE */

      default:
         return QCBOR_ERR_UNEXPECTED_TYPE;
   }

   return QCBOR_SUCCESS;
}


void QCBORDecode_GetDoubleConvertInternal(QCBORDecodeContext *pMe,
                                          uint32_t            uConvertTypes,
                                          double             *pdValue,
                                          QCBORItem          *pItem)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   QCBORItem Item;

   QCBORError uError = QCBORDecode_GetNext(pMe, &Item);
   if(uError) {
      pMe->uLastError = (uint8_t)uError;
      return;
   }

   if(pItem) {
      *pItem = Item;
   }

   pMe->uLastError = (uint8_t)ConvertDouble(&Item, uConvertTypes, pdValue);
}


void QCBORDecode_GetDoubleConvertInternalInMapN(QCBORDecodeContext *pMe,
                                               int64_t             nLabel,
                                               uint32_t            uConvertTypes,
                                               double             *pdValue,
                                               QCBORItem          *pItem)
{
   QCBORDecode_GetItemInMapN(pMe, nLabel, QCBOR_TYPE_ANY, pItem);
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   pMe->uLastError = (uint8_t)ConvertDouble(pItem, uConvertTypes, pdValue);
}


void QCBORDecode_GetDoubleConvertInternalInMapSZ(QCBORDecodeContext *pMe,
                                               const char *          szLabel,
                                               uint32_t              uConvertTypes,
                                               double               *pdValue,
                                               QCBORItem            *pItem)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   QCBORDecode_GetItemInMapSZ(pMe, szLabel, QCBOR_TYPE_ANY, pItem);
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   pMe->uLastError = (uint8_t)ConvertDouble(pItem, uConvertTypes, pdValue);
}


#ifndef QCBOR_DISABLE_FLOAT_HW_USE
static double ConvertBigNumToDouble(const UsefulBufC BigNum)
{
   double dResult;

   dResult = 0.0;
   const uint8_t *pByte = BigNum.ptr;
   size_t uLen = BigNum.len;
   /* This will overflow and become the float value INFINITY if the number
    is too large to fit. */
   while(uLen--) {
      dResult = (dResult * 256.0) + (double)*pByte++;
   }

   return dResult;
}
#endif /* QCBOR_DISABLE_FLOAT_HW_USE */


static QCBORError
DoubleConvertAll(const QCBORItem *pItem, uint32_t uConvertTypes, double *pdValue)
{
#ifndef QCBOR_DISABLE_FLOAT_HW_USE
   /*
   https://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html

   */
   switch(pItem->uDataType) {

#ifndef QCBOR_CONFIG_DISABLE_EXP_AND_MANTISSA
      case QCBOR_TYPE_DECIMAL_FRACTION:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_DECIMAL_FRACTION) {
            // Underflow gives 0, overflow gives infinity
            *pdValue = (double)pItem->val.expAndMantissa.Mantissa.nInt *
                        pow(10.0, (double)pItem->val.expAndMantissa.nExponent);
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

      case QCBOR_TYPE_BIGFLOAT:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_BIGFLOAT ) {
            // Underflow gives 0, overflow gives infinity
            *pdValue = (double)pItem->val.expAndMantissa.Mantissa.nInt *
                              exp2((double)pItem->val.expAndMantissa.nExponent);
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;
#endif /* ndef QCBOR_CONFIG_DISABLE_EXP_AND_MANTISSA */

      case QCBOR_TYPE_POSBIGNUM:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_BIG_NUM) {
            *pdValue = ConvertBigNumToDouble(pItem->val.bigNum);
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

      case QCBOR_TYPE_NEGBIGNUM:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_BIG_NUM) {
            *pdValue = -1-ConvertBigNumToDouble(pItem->val.bigNum);
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

#ifndef QCBOR_CONFIG_DISABLE_EXP_AND_MANTISSA
      case QCBOR_TYPE_DECIMAL_FRACTION_POS_BIGNUM:
         if(uConvertTypes & QCBOR_CONVERT_TYPE_DECIMAL_FRACTION) {
            double dMantissa = ConvertBigNumToDouble(pItem->val.expAndMantissa.Mantissa.bigNum);
            *pdValue = dMantissa * pow(10, (double)pItem->val.expAndMantissa.nExponent);
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

      case QCBOR_TYPE_DECIMAL_FRACTION_NEG_BIGNUM:
        if(uConvertTypes & QCBOR_CONVERT_TYPE_DECIMAL_FRACTION) {
         double dMantissa = -ConvertBigNumToDouble(pItem->val.expAndMantissa.Mantissa.bigNum);
         *pdValue = dMantissa * pow(10, (double)pItem->val.expAndMantissa.nExponent);
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

      case QCBOR_TYPE_BIGFLOAT_POS_BIGNUM:
        if(uConvertTypes & QCBOR_CONVERT_TYPE_BIGFLOAT) {
         double dMantissa = ConvertBigNumToDouble(pItem->val.expAndMantissa.Mantissa.bigNum);
         *pdValue = dMantissa * exp2((double)pItem->val.expAndMantissa.nExponent);
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;

      case QCBOR_TYPE_BIGFLOAT_NEG_BIGNUM:
        if(uConvertTypes & QCBOR_CONVERT_TYPE_BIGFLOAT) {
         double dMantissa = -1-ConvertBigNumToDouble(pItem->val.expAndMantissa.Mantissa.bigNum);
         *pdValue = dMantissa * exp2((double)pItem->val.expAndMantissa.nExponent);
         } else {
            return QCBOR_ERR_UNEXPECTED_TYPE;
         }
         break;
#endif /* ndef QCBOR_CONFIG_DISABLE_EXP_AND_MANTISSA */

      default:
         return QCBOR_ERR_UNEXPECTED_TYPE;
   }

   return QCBOR_SUCCESS;

#else
   (void)pItem;
   (void)uConvertTypes;
   (void)pdValue;
   return QCBOR_ERR_HW_FLOAT_DISABLED;
#endif /* QCBOR_DISABLE_FLOAT_HW_USE */

}


/*
   Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetDoubleConvertAll(QCBORDecodeContext *pMe,
                                     uint32_t           uConvertTypes,
                                     double *pdValue)
{

   QCBORItem Item;

   QCBORDecode_GetDoubleConvertInternal(pMe, uConvertTypes, pdValue, &Item);

   if(pMe->uLastError == QCBOR_SUCCESS) {
      // The above conversion succeeded
      return;
   }

   if(pMe->uLastError != QCBOR_ERR_UNEXPECTED_TYPE) {
      // The above conversion failed in a way that code below can't correct
      return;
   }

   pMe->uLastError = (uint8_t)DoubleConvertAll(&Item, uConvertTypes, pdValue);
}


/*
   Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetDoubleConvertAllInMapN(QCBORDecodeContext *pMe,
                                           int64_t             nLabel,
                                           uint32_t            uConvertTypes,
                                           double             *pdValue)
{
   QCBORItem Item;

   QCBORDecode_GetDoubleConvertInternalInMapN(pMe, nLabel, uConvertTypes, pdValue, &Item);

   if(pMe->uLastError == QCBOR_SUCCESS) {
      // The above conversion succeeded
      return;
   }

   if(pMe->uLastError != QCBOR_ERR_UNEXPECTED_TYPE) {
      // The above conversion failed in a way that code below can't correct
      return;
   }

   pMe->uLastError = (uint8_t)DoubleConvertAll(&Item, uConvertTypes, pdValue);
}


/*
   Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetDoubleConvertAllInMapSZ(QCBORDecodeContext *pMe,
                                            const char         *szLabel,
                                            uint32_t            uConvertTypes,
                                            double             *pdValue)
{
   QCBORItem Item;
   QCBORDecode_GetDoubleConvertInternalInMapSZ(pMe, szLabel, uConvertTypes, pdValue, &Item);

   if(pMe->uLastError == QCBOR_SUCCESS) {
      // The above conversion succeeded
      return;
   }

   if(pMe->uLastError != QCBOR_ERR_UNEXPECTED_TYPE) {
      // The above conversion failed in a way that code below can't correct
      return;
   }

   pMe->uLastError = (uint8_t)DoubleConvertAll(&Item, uConvertTypes, pdValue);
}




#ifndef QCBOR_CONFIG_DISABLE_EXP_AND_MANTISSA
static inline UsefulBufC ConvertIntToBigNum(uint64_t uInt, UsefulBuf Buffer)
{
   while((uInt & 0xff00000000000000UL) == 0) {
      uInt = uInt << 8;
   };

   UsefulOutBuf UOB;

   UsefulOutBuf_Init(&UOB, Buffer);

   while(uInt) {
      const uint64_t xx = uInt & 0xff00000000000000UL;
      UsefulOutBuf_AppendByte(&UOB, (uint8_t)((uInt & 0xff00000000000000UL) >> 56));
      uInt = uInt << 8;
      (void)xx;
   }

   return UsefulOutBuf_OutUBuf(&UOB);
}


static QCBORError MantissaAndExponentTypeHandler(QCBORDecodeContext *pMe,
                                                 TagSpecification    TagSpec,
                                                 QCBORItem          *pItem)
{
   QCBORError uErr;
   // Loops runs at most 1.5 times. Making it a loop saves object code.
   while(1) {
      uErr = CheckTagRequirement(TagSpec, pItem);
      if(uErr != QCBOR_SUCCESS) {
         goto Done;
      }

      if(pItem->uDataType != QCBOR_TYPE_ARRAY) {
         break; // Successful exit. Moving on to finish decoding.
      }

      // The item is an array, which means an undecoded
      // mantissa and exponent, so decode it. It will then
      // have a different type and exit the loop if.
      uErr = QCBORDecode_MantissaAndExponent(pMe, pItem);
      if(uErr != QCBOR_SUCCESS) {
         goto Done;
      }

      // Second time around, the type must match.
      TagSpec.uTagRequirement = QCBOR_TAG_REQUIREMENT_TAG;
   }
Done:
   return uErr;
}


static void ProcessMantissaAndExponent(QCBORDecodeContext *pMe,
                                       TagSpecification    TagSpec,
                                       QCBORItem          *pItem,
                                       int64_t            *pnMantissa,
                                       int64_t            *pnExponent)
{
   QCBORError uErr;

   uErr = MantissaAndExponentTypeHandler(pMe, TagSpec, pItem);
   if(uErr != QCBOR_SUCCESS) {
      goto Done;
   }

   switch (pItem->uDataType) {

      case QCBOR_TYPE_DECIMAL_FRACTION:
      case QCBOR_TYPE_BIGFLOAT:
         *pnMantissa = pItem->val.expAndMantissa.Mantissa.nInt;
         *pnExponent = pItem->val.expAndMantissa.nExponent;
         break;

      case QCBOR_TYPE_DECIMAL_FRACTION_POS_BIGNUM:
      case QCBOR_TYPE_BIGFLOAT_POS_BIGNUM:
         *pnExponent = pItem->val.expAndMantissa.nExponent;
         uErr = ConvertPositiveBigNumToSigned(pItem->val.expAndMantissa.Mantissa.bigNum, pnMantissa);
         break;

      case QCBOR_TYPE_DECIMAL_FRACTION_NEG_BIGNUM:
      case QCBOR_TYPE_BIGFLOAT_NEG_BIGNUM:
         *pnExponent = pItem->val.expAndMantissa.nExponent;
         uErr = ConvertNegativeBigNumToSigned(pItem->val.expAndMantissa.Mantissa.bigNum, pnMantissa);
         break;

      default:
         uErr = QCBOR_ERR_UNEXPECTED_TYPE;
   }

   Done:
      pMe->uLastError = (uint8_t)uErr;
}


static void ProcessMantissaAndExponentBig(QCBORDecodeContext *pMe,
                                          TagSpecification    TagSpec,
                                          QCBORItem          *pItem,
                                          UsefulBuf           BufferForMantissa,
                                          UsefulBufC         *pMantissa,
                                          bool               *pbIsNegative,
                                          int64_t            *pnExponent)
{
   QCBORError uErr;

   uErr = MantissaAndExponentTypeHandler(pMe, TagSpec, pItem);
   if(uErr != QCBOR_SUCCESS) {
      goto Done;
   }

   uint64_t uMantissa;

   switch (pItem->uDataType) {

      case QCBOR_TYPE_DECIMAL_FRACTION:
      case QCBOR_TYPE_BIGFLOAT:
         if(pItem->val.expAndMantissa.Mantissa.nInt >= 0) {
            uMantissa = (uint64_t)pItem->val.expAndMantissa.Mantissa.nInt;
            *pbIsNegative = false;
         } else {
            uMantissa = (uint64_t)-pItem->val.expAndMantissa.Mantissa.nInt;
            *pbIsNegative = true;
         }
         *pMantissa = ConvertIntToBigNum(uMantissa, BufferForMantissa);
         *pnExponent = pItem->val.expAndMantissa.nExponent;
         break;

      case QCBOR_TYPE_DECIMAL_FRACTION_POS_BIGNUM:
      case QCBOR_TYPE_BIGFLOAT_POS_BIGNUM:
         *pnExponent = pItem->val.expAndMantissa.nExponent;
         *pMantissa = pItem->val.expAndMantissa.Mantissa.bigNum;
         *pbIsNegative = false;
         break;

      case QCBOR_TYPE_DECIMAL_FRACTION_NEG_BIGNUM:
      case QCBOR_TYPE_BIGFLOAT_NEG_BIGNUM:
         *pnExponent = pItem->val.expAndMantissa.nExponent;
         *pMantissa = pItem->val.expAndMantissa.Mantissa.bigNum;
         *pbIsNegative = true;
         break;

      default:
         uErr = QCBOR_ERR_UNEXPECTED_TYPE;
   }

Done:
   pMe->uLastError = (uint8_t)uErr;
}


/*
 Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetDecimalFraction(QCBORDecodeContext *pMe,
                                    uint8_t             uTagRequirement,
                                    int64_t             *pnMantissa,
                                    int64_t             *pnExponent)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   QCBORItem Item;
   QCBORError uError = QCBORDecode_GetNext(pMe, &Item);
   if(uError) {
      pMe->uLastError = (uint8_t)uError;
      return;
   }

   const TagSpecification TagSpec =
   {
      uTagRequirement,
      {QCBOR_TYPE_DECIMAL_FRACTION, QCBOR_TYPE_DECIMAL_FRACTION_POS_BIGNUM,
         QCBOR_TYPE_DECIMAL_FRACTION_NEG_BIGNUM, QCBOR_TYPE_NONE},
      {QCBOR_TYPE_ARRAY, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE}
   };

   ProcessMantissaAndExponent(pMe, TagSpec, &Item, pnMantissa, pnExponent);
}


/*
 Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetDecimalFractionInMapN(QCBORDecodeContext *pMe,
                                          int64_t             nLabel,
                                          uint8_t             uTagRequirement,
                                          int64_t             *pnMantissa,
                                          int64_t             *pnExponent)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   QCBORItem Item;
   QCBORDecode_GetItemInMapN(pMe, nLabel, QCBOR_TYPE_ANY, &Item);

   const TagSpecification TagSpec =
   {
      uTagRequirement,
      {QCBOR_TYPE_DECIMAL_FRACTION, QCBOR_TYPE_DECIMAL_FRACTION_POS_BIGNUM,
         QCBOR_TYPE_DECIMAL_FRACTION_NEG_BIGNUM, QCBOR_TYPE_NONE},
      {QCBOR_TYPE_ARRAY, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE}
   };

   ProcessMantissaAndExponent(pMe, TagSpec, &Item, pnMantissa, pnExponent);
}


/*
 Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetDecimalFractionInMapSZ(QCBORDecodeContext *pMe,
                                           const char         *szLabel,
                                           uint8_t             uTagRequirement,
                                           int64_t             *pnMantissa,
                                           int64_t             *pnExponent)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   QCBORItem Item;
   QCBORDecode_GetItemInMapSZ(pMe, szLabel, QCBOR_TYPE_ANY, &Item);

   const TagSpecification TagSpec =
   {
      uTagRequirement,
      {QCBOR_TYPE_DECIMAL_FRACTION, QCBOR_TYPE_DECIMAL_FRACTION_POS_BIGNUM,
         QCBOR_TYPE_DECIMAL_FRACTION_NEG_BIGNUM, QCBOR_TYPE_NONE},
      {QCBOR_TYPE_ARRAY, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE}
   };

   ProcessMantissaAndExponent(pMe, TagSpec, &Item, pnMantissa, pnExponent);
}


/*
 Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetDecimalFractionBig(QCBORDecodeContext *pMe,
                                       uint8_t             uTagRequirement,
                                       UsefulBuf          MantissaBuffer,
                                       UsefulBufC         *pMantissa,
                                       bool               *pbMantissaIsNegative,
                                       int64_t            *pnExponent)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   QCBORItem Item;
   QCBORError uError = QCBORDecode_GetNext(pMe, &Item);
   if(uError) {
      pMe->uLastError = (uint8_t)uError;
      return;
   }

   const TagSpecification TagSpec =
   {
      uTagRequirement,
      {QCBOR_TYPE_DECIMAL_FRACTION, QCBOR_TYPE_DECIMAL_FRACTION_POS_BIGNUM,
         QCBOR_TYPE_DECIMAL_FRACTION_NEG_BIGNUM, QCBOR_TYPE_NONE},
      {QCBOR_TYPE_ARRAY, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE}
   };

   ProcessMantissaAndExponentBig(pMe,
                                 TagSpec,
                                 &Item,
                                 MantissaBuffer,
                                 pMantissa,
                                 pbMantissaIsNegative,
                                 pnExponent);
}


/*
 Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetDecimalFractionBigInMapN(QCBORDecodeContext *pMe,
                                             int64_t             nLabel,
                                             uint8_t             uTagRequirement,
                                             UsefulBuf           BufferForMantissa,
                                             UsefulBufC         *pMantissa,
                                             bool               *pbIsNegative,
                                             int64_t            *pnExponent)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   QCBORItem Item;
   QCBORDecode_GetItemInMapN(pMe, nLabel, QCBOR_TYPE_ANY, &Item);
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   const TagSpecification TagSpec =
   {
      uTagRequirement,
      {QCBOR_TYPE_DECIMAL_FRACTION, QCBOR_TYPE_DECIMAL_FRACTION_POS_BIGNUM,
         QCBOR_TYPE_DECIMAL_FRACTION_NEG_BIGNUM, QCBOR_TYPE_NONE},
      {QCBOR_TYPE_ARRAY, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE}
   };

   ProcessMantissaAndExponentBig(pMe,
                                 TagSpec,
                                 &Item,
                                 BufferForMantissa,
                                 pMantissa,
                                 pbIsNegative,
                                 pnExponent);
}


/*
 Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetDecimalFractionBigInMapSZ(QCBORDecodeContext *pMe,
                                              const char         *szLabel,
                                              uint8_t             uTagRequirement,
                                              UsefulBuf           BufferForMantissa,
                                              UsefulBufC         *pMantissa,
                                              bool               *pbIsNegative,
                                              int64_t            *pnExponent)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   QCBORItem Item;
   QCBORDecode_GetItemInMapSZ(pMe, szLabel, QCBOR_TYPE_ANY, &Item);
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   const TagSpecification TagSpec =
   {
      uTagRequirement,
      {QCBOR_TYPE_DECIMAL_FRACTION, QCBOR_TYPE_DECIMAL_FRACTION_POS_BIGNUM,
         QCBOR_TYPE_DECIMAL_FRACTION_NEG_BIGNUM, QCBOR_TYPE_NONE},
      {QCBOR_TYPE_ARRAY, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE}
   };

   ProcessMantissaAndExponentBig(pMe, TagSpec, &Item, BufferForMantissa, pMantissa, pbIsNegative, pnExponent);
}


/*
 Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetBigFloat(QCBORDecodeContext *pMe,
                             uint8_t             uTagRequirement,
                             int64_t             *pnMantissa,
                             int64_t             *pnExponent)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   QCBORItem Item;
   QCBORError uError = QCBORDecode_GetNext(pMe, &Item);
   if(uError) {
      pMe->uLastError = (uint8_t)uError;
      return;
   }
   const TagSpecification TagSpec =
   {
      uTagRequirement,
      {QCBOR_TYPE_BIGFLOAT, QCBOR_TYPE_BIGFLOAT_POS_BIGNUM,
         QCBOR_TYPE_BIGFLOAT_NEG_BIGNUM, QCBOR_TYPE_NONE},
      {QCBOR_TYPE_ARRAY, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE}
   };

   ProcessMantissaAndExponent(pMe, TagSpec, &Item, pnMantissa, pnExponent);
}


/*
 Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetBigFloatInMapN(QCBORDecodeContext *pMe,
                                   int64_t             nLabel,
                                   uint8_t             uTagRequirement,
                                   int64_t            *pnMantissa,
                                   int64_t            *pnExponent)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   QCBORItem Item;
   QCBORDecode_GetItemInMapN(pMe, nLabel, QCBOR_TYPE_ANY, &Item);
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   const TagSpecification TagSpec =
   {
      uTagRequirement,
      {QCBOR_TYPE_BIGFLOAT, QCBOR_TYPE_BIGFLOAT_POS_BIGNUM,
         QCBOR_TYPE_BIGFLOAT_NEG_BIGNUM, QCBOR_TYPE_NONE},
      {QCBOR_TYPE_ARRAY, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE}
   };

   ProcessMantissaAndExponent(pMe, TagSpec, &Item, pnMantissa, pnExponent);
}


/*
 Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetBigFloatInMapSZ(QCBORDecodeContext *pMe,
                                    const char         *szLabel,
                                    uint8_t             uTagRequirement,
                                    int64_t            *pnMantissa,
                                    int64_t            *pnExponent)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   QCBORItem Item;
   QCBORDecode_GetItemInMapSZ(pMe, szLabel, QCBOR_TYPE_ANY, &Item);
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   const TagSpecification TagSpec =
   {
      uTagRequirement,
      {QCBOR_TYPE_BIGFLOAT, QCBOR_TYPE_BIGFLOAT_POS_BIGNUM,
         QCBOR_TYPE_BIGFLOAT_NEG_BIGNUM, QCBOR_TYPE_NONE},
      {QCBOR_TYPE_ARRAY, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE}
   };

   ProcessMantissaAndExponent(pMe, TagSpec, &Item, pnMantissa, pnExponent);
}


/*
 Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetBigFloatBig(QCBORDecodeContext *pMe,
                                uint8_t             uTagRequirement,
                                UsefulBuf          MantissaBuffer,
                                UsefulBufC         *pMantissa,
                                bool               *pbMantissaIsNegative,
                                int64_t            *pnExponent)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   QCBORItem Item;
   QCBORError uError = QCBORDecode_GetNext(pMe, &Item);
   if(uError) {
      pMe->uLastError = (uint8_t)uError;
      return;
   }

   const TagSpecification TagSpec =
   {
      uTagRequirement,
      {QCBOR_TYPE_BIGFLOAT, QCBOR_TYPE_BIGFLOAT_POS_BIGNUM,
         QCBOR_TYPE_BIGFLOAT_NEG_BIGNUM, QCBOR_TYPE_NONE},
      {QCBOR_TYPE_ARRAY, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE}
   };

   ProcessMantissaAndExponentBig(pMe, TagSpec, &Item, MantissaBuffer, pMantissa, pbMantissaIsNegative, pnExponent);
}


/*
 Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetBigFloatBigInMapN(QCBORDecodeContext *pMe,
                                      int64_t             nLabel,
                                      uint8_t             uTagRequirement,
                                      UsefulBuf           BufferForMantissa,
                                      UsefulBufC         *pMantissa,
                                      bool               *pbIsNegative,
                                      int64_t            *pnExponent)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   QCBORItem Item;
   QCBORDecode_GetItemInMapN(pMe, nLabel, QCBOR_TYPE_ANY, &Item);
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   const TagSpecification TagSpec =
   {
      uTagRequirement,
      {QCBOR_TYPE_BIGFLOAT, QCBOR_TYPE_BIGFLOAT_POS_BIGNUM,
         QCBOR_TYPE_BIGFLOAT_NEG_BIGNUM, QCBOR_TYPE_NONE},
      {QCBOR_TYPE_ARRAY, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE}
   };

   ProcessMantissaAndExponentBig(pMe,
                                 TagSpec,
                                 &Item,
                                 BufferForMantissa,
                                 pMantissa,
                                 pbIsNegative,
                                 pnExponent);
}


/*
 Public function, see header qcbor/qcbor_decode.h file
*/
void QCBORDecode_GetBigFloatBigInMapSZ(QCBORDecodeContext *pMe,
                                       const char         *szLabel,
                                       uint8_t             uTagRequirement,
                                       UsefulBuf           BufferForMantissa,
                                       UsefulBufC         *pMantissa,
                                       bool               *pbIsNegative,
                                       int64_t            *pnExponent)
{
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   QCBORItem Item;
   QCBORDecode_GetItemInMapSZ(pMe, szLabel, QCBOR_TYPE_ANY, &Item);
   if(pMe->uLastError != QCBOR_SUCCESS) {
      return;
   }

   const TagSpecification TagSpec =
   {
      uTagRequirement,
      {QCBOR_TYPE_BIGFLOAT, QCBOR_TYPE_BIGFLOAT_POS_BIGNUM,
         QCBOR_TYPE_BIGFLOAT_NEG_BIGNUM, QCBOR_TYPE_NONE},
      {QCBOR_TYPE_ARRAY, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE, QCBOR_TYPE_NONE}
   };

   ProcessMantissaAndExponentBig(pMe,
                                 TagSpec,
                                 &Item,
                                 BufferForMantissa,
                                 pMantissa,
                                 pbIsNegative,
                                 pnExponent);
}

#endif /* QCBOR_CONFIG_DISABLE_EXP_AND_MANTISSA */