scuffed-code/icu4c/source/i18n/uspoof_impl.cpp
Andy Heninger 9715eae02c ICU-4790 spoof impl merged to trunk.
X-SVN-Rev: 25534
2009-03-09 23:40:15 +00:00

842 lines
26 KiB
C++

/*
**********************************************************************
* Copyright (C) 2008-2009, International Business Machines
* Corporation and others. All Rights Reserved.
**********************************************************************
*/
#include "unicode/utypes.h"
#include "unicode/uspoof.h"
#include "unicode/unorm.h"
#include "utrie2.h"
#include "cmemory.h"
#include "udatamem.h"
#include "umutex.h"
#include "udataswp.h"
#include "uassert.h"
#include "uspoof_impl.h"
U_NAMESPACE_BEGIN
UOBJECT_DEFINE_RTTI_IMPLEMENTATION(SpoofImpl)
SpoofImpl::SpoofImpl(SpoofData *data, UErrorCode &status) :
fMagic(0), fSpoofData(NULL), fAllowedCharsSet(NULL) {
if (U_FAILURE(status)) {
return;
}
fMagic = USPOOF_MAGIC;
fSpoofData = data;
fChecks = USPOOF_ALL_CHECKS;
UnicodeSet *allowedCharsSet = new UnicodeSet(0, 0x10ffff);
if (allowedCharsSet == NULL) {
status = U_MEMORY_ALLOCATION_ERROR;
}
allowedCharsSet->freeze();
fAllowedCharsSet = allowedCharsSet;
}
SpoofImpl::SpoofImpl() {
fMagic = USPOOF_MAGIC;
fSpoofData = NULL;
fChecks = USPOOF_ALL_CHECKS;
UnicodeSet *allowedCharsSet = new UnicodeSet(0, 0x10ffff);
allowedCharsSet->freeze();
fAllowedCharsSet = allowedCharsSet;
}
// Copy Constructor, used by the user level clone() function.
SpoofImpl::SpoofImpl(const SpoofImpl &src, UErrorCode &status) :
fMagic(0), fSpoofData(NULL), fAllowedCharsSet(NULL) {
if (U_FAILURE(status)) {
return;
}
fMagic = src.fMagic;
fChecks = src.fChecks;
if (src.fSpoofData != NULL) {
fSpoofData = src.fSpoofData->addReference();
}
fCheckMask = src.fCheckMask;
fAllowedCharsSet = static_cast<const UnicodeSet *>(src.fAllowedCharsSet->clone());
if (fAllowedCharsSet == NULL) {
status = U_MEMORY_ALLOCATION_ERROR;
}
}
SpoofImpl::~SpoofImpl() {
fMagic = 0; // head off application errors by preventing use of
// of deleted objects.
if (fSpoofData != NULL) {
fSpoofData->removeReference(); // Will delete if refCount goes to zero.
}
delete fAllowedCharsSet;
}
//
// Incoming parameter check on Status and the SpoofChecker object
// received from the C API.
//
const SpoofImpl *SpoofImpl::validateThis(const USpoofChecker *sc, UErrorCode &status) {
if (U_FAILURE(status)) {
return NULL;
}
if (sc == NULL) {
status = U_ILLEGAL_ARGUMENT_ERROR;
return NULL;
};
SpoofImpl *This = (SpoofImpl *)sc;
if (This->fMagic != USPOOF_MAGIC ||
This->fSpoofData == NULL) {
status = U_INVALID_FORMAT_ERROR;
return NULL;
}
if (!SpoofData::validateDataVersion(This->fSpoofData->fRawData, status)) {
return NULL;
}
return This;
}
SpoofImpl *SpoofImpl::validateThis(USpoofChecker *sc, UErrorCode &status) {
return const_cast<SpoofImpl *>
(SpoofImpl::validateThis(const_cast<const USpoofChecker *>(sc), status));
}
//--------------------------------------------------------------------------------------
//
// confusableLookup() This is the heart of the confusable skeleton generation
// implementation.
//
// Given a source character, produce the corresponding
// replacement character(s)
//
//---------------------------------------------------------------------------------------
int32_t SpoofImpl::confusableLookup(UChar32 inChar, int32_t tableMask, UChar *destBuf) const {
// Binary search the spoof data key table for the inChar
int32_t *low = fSpoofData->fCFUKeys;
int32_t *mid = NULL;
int32_t *limit = low + fSpoofData->fRawData->fCFUKeysSize;
UChar midc;
do {
int32_t delta = (limit-low)/2;
mid = low + delta;
midc = *mid & 0x1fffff;
if (inChar == midc) {
goto foundChar;
} else if (inChar < midc) {
limit = mid;
} else {
low = mid;
}
} while (low < limit-1);
mid = low;
midc = *mid & 0x1fffff;
if (inChar != midc) {
// Char not found. It maps to itself.
int i = 0;
U16_APPEND_UNSAFE(destBuf, i, inChar)
return i;
}
foundChar:
int32_t keyFlags = *mid & 0xff000000;
if ((keyFlags & tableMask) == 0) {
// We found the right key char, but the entry doesn't pertain to the
// table we need. See if there is an adjacent key that does
if (keyFlags & USPOOF_KEY_MULTIPLE_VALUES) {
int32_t *altMid;
for (altMid = mid-1; (*altMid&0x00ffffff) == inChar; altMid--) {
keyFlags = *altMid & 0xff000000;
if (keyFlags & tableMask) {
mid = altMid;
goto foundKey;
}
}
for (altMid = mid+1; (*altMid&0x00ffffff) == inChar; altMid++) {
keyFlags = *altMid & 0xff000000;
if (keyFlags & tableMask) {
mid = altMid;
goto foundKey;
}
}
}
// No key entry for this char & table.
// The input char maps to itself.
int i = 0;
U16_APPEND_UNSAFE(destBuf, i, inChar)
return i;
}
foundKey:
int32_t stringLen = USPOOF_KEY_LENGTH_FIELD(keyFlags) + 1;
int32_t keyTableIndex = mid - fSpoofData->fCFUKeys;
// Value is either a UChar (for strings of length 1) or
// an index into the string table (for longer strings)
uint16_t value = fSpoofData->fCFUValues[keyTableIndex];
if (stringLen == 1) {
destBuf[0] = value;
return 1;
}
// String length of 4 from the above lookup is used for all strings of length >= 4.
// For these, get the real length from the string lengths table,
// which maps string table indexes to lengths.
// All strings of the same length are stored contiguously in the string table.
// 'value' from the lookup above is the starting index for the desired string.
int32_t ix;
if (stringLen == 4) {
// TODO:
int32_t stringLengthsLimit = fSpoofData->fRawData->fCFUStringLengthsSize;
for (ix = 0; ix < stringLengthsLimit; ix++) {
if (fSpoofData->fCFUStringLengths[ix].fLastString >= value) {
stringLen = fSpoofData->fCFUStringLengths[ix].fStrLength;
break;
}
}
U_ASSERT(ix < stringLengthsLimit);
}
U_ASSERT(value + stringLen < fSpoofData->fRawData->fCFUStringTableLen);
UChar *src = &fSpoofData->fCFUStrings[value];
for (ix=0; ix<stringLen; ix++) {
destBuf[ix] = src[ix];
}
return stringLen;
}
//---------------------------------------------------------------------------------------
//
// wholeScriptCheck()
//
// Input text is already normalized to NFKD
// Return the set of scripts, each of which can represent something that is
// confusable with the input text. The script of the input text
// is included; input consisting of characters from a single script will
// always produce a result consisting of a set containing that script.
//
//---------------------------------------------------------------------------------------
void SpoofImpl::wholeScriptCheck(
const UChar *text, int32_t length, ScriptSet *result, UErrorCode &status) const {
int32_t inputIdx = 0;
UChar32 c;
UTrie2 *table =
(fChecks & USPOOF_ANY_CASE) ? fSpoofData->fAnyCaseTrie : fSpoofData->fLowerCaseTrie;
result->setAll();
while (inputIdx < length) {
U16_NEXT(text, inputIdx, length, c);
uint32_t index = utrie2_get32(table, c);
if (index == 0) {
// No confusables in another script for this char.
// TODO: we should change the data to have sets with just the single script
// bit for the script of this char. Gets rid of this special case.
// Until then, grab the script from the char and intersect it with the set.
UScriptCode cpScript = uscript_getScript(c, &status);
U_ASSERT(cpScript > USCRIPT_INHERITED);
result->intersect(cpScript);
} else if (index == 1) {
// Script == Common or Inherited. Nothing to do.
} else {
result->intersect(fSpoofData->fScriptSets[index]);
}
}
}
int32_t SpoofImpl::scriptScan
(const UChar *text, int32_t length, int32_t &pos, UErrorCode &status) const {
if (U_FAILURE(status)) {
return 0;
}
int32_t inputIdx = 0;
UChar32 c;
int32_t scriptCount = 0;
UScriptCode lastScript = USCRIPT_INVALID_CODE;
UScriptCode sc = USCRIPT_INVALID_CODE;
while ((inputIdx < length || length == -1) && scriptCount < 2) {
U16_NEXT(text, inputIdx, length, c);
if (c == 0 && length == -1) {
break;
}
sc = uscript_getScript(c, &status);
if (sc == USCRIPT_COMMON || sc == USCRIPT_INHERITED || sc == USCRIPT_UNKNOWN) {
continue;
}
if (sc != lastScript) {
scriptCount++;
lastScript = sc;
}
}
if (scriptCount == 2) {
pos = inputIdx;
}
return scriptCount;
}
// Convert a text format hex number. Utility function used by builder code. Static.
// Input: UChar *string text. Output: a UChar32
// Input has been pre-checked, and will have no non-hex chars.
// The number must fall in the code point range of 0..0x10ffff
// Static Function.
UChar32 SpoofImpl::ScanHex(const UChar *s, int32_t start, int32_t limit, UErrorCode &status) {
if (U_FAILURE(status)) {
return 0;
}
U_ASSERT(limit-start > 0);
uint32_t val = 0;
int i;
for (i=start; i<limit; i++) {
int digitVal = s[i] - 0x30;
if (digitVal>9) {
digitVal = 0xa + (s[i] - 0x41); // Upper Case 'A'
}
if (digitVal>15) {
digitVal = 0xa + (s[i] - 0x61); // Lower Case 'a'
}
U_ASSERT(digitVal <= 0xf);
val <<= 4;
val += digitVal;
}
if (val > 0x10ffff) {
status = U_PARSE_ERROR;
val = 0;
}
return (UChar32)val;
}
//----------------------------------------------------------------------------------------------
//
// class SpoofData Implementation
//
//----------------------------------------------------------------------------------------------
UBool SpoofData::validateDataVersion(const SpoofDataHeader *rawData, UErrorCode &status) {
if (U_FAILURE(status) ||
rawData == NULL ||
rawData->fMagic != USPOOF_MAGIC ||
rawData->fFormatVersion[0] > 1 ||
rawData->fFormatVersion[1] > 0) {
status = U_INVALID_FORMAT_ERROR;
return FALSE;
}
return TRUE;
}
//
// SpoofData::getDefault() - return a wrapper around the spoof data that is
// baked into the default ICU data.
//
SpoofData *SpoofData::getDefault(UErrorCode &status) {
// TODO: Cache it. Lazy create, keep until cleanup.
UDataMemory *udm = udata_open(NULL, "cfu", "confusables", &status);
if (U_FAILURE(status)) {
return NULL;
}
SpoofData *This = new SpoofData(udm, status);
if (U_FAILURE(status)) {
delete This;
return NULL;
}
if (This == NULL) {
status = U_MEMORY_ALLOCATION_ERROR;
}
return This;
}
SpoofData::SpoofData(UDataMemory *udm, UErrorCode &status)
{
reset();
if (U_FAILURE(status)) {
return;
}
fRawData = reinterpret_cast<SpoofDataHeader *>
((char *)(udm->pHeader) + udm->pHeader->dataHeader.headerSize);
fUDM = udm;
validateDataVersion(fRawData, status);
initPtrs(status);
}
SpoofData::SpoofData(const void *data, int32_t length, UErrorCode &status)
{
reset();
if (U_FAILURE(status)) {
return;
}
if ((size_t)length < sizeof(SpoofDataHeader)) {
status = U_INVALID_FORMAT_ERROR;
return;
}
void *ncData = const_cast<void *>(data);
fRawData = static_cast<SpoofDataHeader *>(ncData);
if (length < fRawData->fLength) {
status = U_INVALID_FORMAT_ERROR;
return;
}
validateDataVersion(fRawData, status);
initPtrs(status);
}
// Spoof Data constructor for use from data builder.
// Initializes a new, empty data area that will be populated later.
SpoofData::SpoofData(UErrorCode &status) {
reset();
if (U_FAILURE(status)) {
return;
}
fDataOwned = true;
fRefCount = 1;
// The spoof header should already be sized to be a multiple of 16 bytes.
// Just in case it's not, round it up.
uint32_t initialSize = (sizeof(SpoofDataHeader) + 15) & ~15;
U_ASSERT(initialSize == sizeof(SpoofDataHeader));
fRawData = static_cast<SpoofDataHeader *>(uprv_malloc(initialSize));
fMemLimit = initialSize;
if (fRawData == NULL) {
status = U_MEMORY_ALLOCATION_ERROR;
return;
}
uprv_memset(fRawData, 0, initialSize);
fRawData->fMagic = USPOOF_MAGIC;
fRawData->fFormatVersion[0] = 1;
fRawData->fFormatVersion[1] = 0;
fRawData->fFormatVersion[2] = 0;
fRawData->fFormatVersion[3] = 0;
initPtrs(status);
}
// reset() - initialize all fields.
// Should be updated if any new fields are added.
// Called by constructors to put things in a known initial state.
void SpoofData::reset() {
fRawData = NULL;
fDataOwned = FALSE;
fUDM = NULL;
fMemLimit = 0;
fRefCount = 1;
fCFUKeys = NULL;
fCFUValues = NULL;
fCFUStringLengths = NULL;
fCFUStrings = NULL;
fAnyCaseTrie = NULL;
fLowerCaseTrie = NULL;
fScriptSets = NULL;
}
// SpoofData::initPtrs()
// Initialize the pointers to the various sections of the raw data.
//
// This function is used both during the Trie building process (multiple
// times, as the individual data sections are added), and
// during the opening of a Spoof Checker from prebuilt data.
//
// The pointers for non-existent data sections (identified by an offset of 0)
// are set to NULL.
//
// Note: During building the data, adding each new data section
// reallocs the raw data area, which likely relocates it, which
// in turn requires reinitializing all of the pointers into it, hence
// multiple calls to this function during building.
//
void SpoofData::initPtrs(UErrorCode &status) {
fCFUKeys = NULL;
fCFUValues = NULL;
fCFUStringLengths = NULL;
fCFUStrings = NULL;
if (U_FAILURE(status)) {
return;
}
if (fRawData->fCFUKeys != 0) {
fCFUKeys = (int32_t *)((char *)fRawData + fRawData->fCFUKeys);
}
if (fRawData->fCFUStringIndex != 0) {
fCFUValues = (uint16_t *)((char *)fRawData + fRawData->fCFUStringIndex);
}
if (fRawData->fCFUStringLengths != 0) {
fCFUStringLengths = (SpoofStringLengthsElement *)((char *)fRawData + fRawData->fCFUStringLengths);
}
if (fRawData->fCFUStringTable != 0) {
fCFUStrings = (UChar *)((char *)fRawData + fRawData->fCFUStringTable);
}
if (fAnyCaseTrie == NULL && fRawData->fAnyCaseTrie != 0) {
fAnyCaseTrie = utrie2_openFromSerialized(UTRIE2_16_VALUE_BITS,
(char *)fRawData + fRawData->fAnyCaseTrie, fRawData->fAnyCaseTrieLength, NULL, &status);
}
if (fLowerCaseTrie == NULL && fRawData->fLowerCaseTrie != 0) {
fLowerCaseTrie = utrie2_openFromSerialized(UTRIE2_16_VALUE_BITS,
(char *)fRawData + fRawData->fLowerCaseTrie, fRawData->fLowerCaseTrieLength, NULL, &status);
}
if (fRawData->fScriptSets != 0) {
fScriptSets = (ScriptSet *)((char *)fRawData + fRawData->fScriptSets);
}
}
SpoofData::~SpoofData() {
utrie2_close(fAnyCaseTrie);
fAnyCaseTrie = NULL;
utrie2_close(fLowerCaseTrie);
fLowerCaseTrie = NULL;
if (fDataOwned) {
uprv_free(fRawData);
}
fRawData = NULL;
if (fUDM != NULL) {
udata_close(fUDM);
}
fUDM = NULL;
}
void SpoofData::removeReference() {
if (umtx_atomic_dec(&fRefCount) == 0) {
delete this;
}
}
SpoofData *SpoofData::addReference() {
umtx_atomic_inc(&fRefCount);
return this;
}
void *SpoofData::reserveSpace(int32_t numBytes, UErrorCode &status) {
if (U_FAILURE(status)) {
return NULL;
}
if (!fDataOwned) {
U_ASSERT(FALSE);
status = U_INTERNAL_PROGRAM_ERROR;
return NULL;
}
numBytes = (numBytes + 15) & ~15; // Round up to a multiple of 16
uint32_t returnOffset = fMemLimit;
fMemLimit += numBytes;
fRawData = static_cast<SpoofDataHeader *>(uprv_realloc(fRawData, fMemLimit));
fRawData->fLength = fMemLimit;
uprv_memset((char *)fRawData + returnOffset, 0, numBytes);
initPtrs(status);
return (char *)fRawData + returnOffset;
}
//----------------------------------------------------------------------------
//
// ScriptSet implementation
//
//----------------------------------------------------------------------------
ScriptSet::ScriptSet() {
for (uint32_t i=0; i<sizeof(bits)/sizeof(uint32_t); i++) {
bits[i] = 0;
}
}
ScriptSet::~ScriptSet() {
}
UBool ScriptSet::operator == (const ScriptSet &other) {
for (uint32_t i=0; i<sizeof(bits)/sizeof(uint32_t); i++) {
if (bits[i] != other.bits[i]) {
return FALSE;
}
}
return TRUE;
}
void ScriptSet::Union(UScriptCode script) {
uint32_t index = script / 32;
uint32_t bit = 1 << (script & 31);
U_ASSERT(index < sizeof(bits)*4);
bits[index] |= bit;
}
void ScriptSet::Union(const ScriptSet &other) {
for (uint32_t i=0; i<sizeof(bits)/sizeof(uint32_t); i++) {
bits[i] |= other.bits[i];
}
}
void ScriptSet::intersect(const ScriptSet &other) {
for (uint32_t i=0; i<sizeof(bits)/sizeof(uint32_t); i++) {
bits[i] &= other.bits[i];
}
}
void ScriptSet::intersect(UScriptCode script) {
uint32_t index = script / 32;
uint32_t bit = 1 << (script & 31);
U_ASSERT(index < sizeof(bits)*4);
uint32_t i;
for (i=0; i<index; i++) {
bits[i] = 0;
}
bits[index] &= bit;
for (i=index+1; i<sizeof(bits)/sizeof(uint32_t); i++) {
bits[i] = 0;
}
}
ScriptSet & ScriptSet::operator =(const ScriptSet &other) {
for (uint32_t i=0; i<sizeof(bits)/sizeof(uint32_t); i++) {
bits[i] = other.bits[i];
}
return *this;
}
void ScriptSet::setAll() {
for (uint32_t i=0; i<sizeof(bits)/sizeof(uint32_t); i++) {
bits[i] = 0xffffffffu;
}
}
void ScriptSet::resetAll() {
for (uint32_t i=0; i<sizeof(bits)/sizeof(uint32_t); i++) {
bits[i] = 0;
}
}
int32_t ScriptSet::countMembers() {
// This bit counter is good for sparse numbers of '1's, which is
// very much the case that we will usually have.
int32_t count = 0;
for (uint32_t i=0; i<sizeof(bits)/sizeof(uint32_t); i++) {
uint32_t x = bits[i];
while (x > 0) {
count++;
x &= (x - 1); // and off the least significant one bit.
}
}
return count;
}
//-----------------------------------------------------------------------------
//
// NFKDBuffer Implementation.
//
//-----------------------------------------------------------------------------
NFKDBuffer::NFKDBuffer(const UChar *text, int32_t length, UErrorCode &status) {
fNormalizedText = NULL;
fNormalizedTextLength = 0;
fOriginalText = text;
if (U_FAILURE(status)) {
return;
}
fNormalizedText = fSmallBuf;
fNormalizedTextLength = unorm_normalize(
text, length, UNORM_NFKD, 0, fNormalizedText, USPOOF_STACK_BUFFER_SIZE, &status);
if (status == U_BUFFER_OVERFLOW_ERROR) {
status = U_ZERO_ERROR;
fNormalizedText = (UChar *)uprv_malloc((fNormalizedTextLength+1)*sizeof(UChar));
if (fNormalizedText == NULL) {
status = U_MEMORY_ALLOCATION_ERROR;
} else {
fNormalizedTextLength = unorm_normalize(text, length, UNORM_NFKD, 0,
fNormalizedText, fNormalizedTextLength+1, &status);
}
}
}
NFKDBuffer::~NFKDBuffer() {
if (fNormalizedText != fSmallBuf) {
delete fNormalizedText;
}
fNormalizedText = 0;
}
const UChar *NFKDBuffer::getBuffer() {
return fNormalizedText;
}
int32_t NFKDBuffer::getLength() {
return fNormalizedTextLength;
}
U_NAMESPACE_END
U_NAMESPACE_USE
//-----------------------------------------------------------------------------
//
// uspoof_swap - byte swap and char encoding swap of spoof data
//
//-----------------------------------------------------------------------------
U_CAPI int32_t U_EXPORT2
uspoof_swap(const UDataSwapper *ds, const void *inData, int32_t length, void *outData,
UErrorCode *status) {
if (status == NULL || U_FAILURE(*status)) {
return 0;
}
if(ds==NULL || inData==NULL || length<-1 || (length>0 && outData==NULL)) {
*status=U_ILLEGAL_ARGUMENT_ERROR;
return 0;
}
//
// Check that the data header is for spoof data.
// (Header contents are defined in gencfu.cpp)
//
const UDataInfo *pInfo = (const UDataInfo *)((const char *)inData+4);
if(!( pInfo->dataFormat[0]==0x43 && /* dataFormat="Cfu " */
pInfo->dataFormat[1]==0x66 &&
pInfo->dataFormat[2]==0x75 &&
pInfo->dataFormat[3]==0x20 &&
pInfo->formatVersion[0]==1 )) {
udata_printError(ds, "uspoof_swap(): data format %02x.%02x.%02x.%02x "
"(format version %02x %02x %02x %02x) is not recognized\n",
pInfo->dataFormat[0], pInfo->dataFormat[1],
pInfo->dataFormat[2], pInfo->dataFormat[3],
pInfo->formatVersion[0], pInfo->formatVersion[1],
pInfo->formatVersion[2], pInfo->formatVersion[3]);
*status=U_UNSUPPORTED_ERROR;
return 0;
}
//
// Swap the data header. (This is the generic ICU Data Header, not the uspoof Specific
// header). This swap also conveniently gets us
// the size of the ICU d.h., which lets us locate the start
// of the uspoof specific data.
//
int32_t headerSize=udata_swapDataHeader(ds, inData, length, outData, status);
//
// Get the Spoof Data Header, and check that it appears to be OK.
//
//
const uint8_t *inBytes =(const uint8_t *)inData+headerSize;
SpoofDataHeader *spoofDH = (SpoofDataHeader *)inBytes;
if (ds->readUInt32(spoofDH->fMagic) != USPOOF_MAGIC ||
ds->readUInt32(spoofDH->fLength) < sizeof(SpoofDataHeader))
{
udata_printError(ds, "uspoof_swap(): Spoof Data header is invalid.\n");
*status=U_UNSUPPORTED_ERROR;
return 0;
}
//
// Prefight operation? Just return the size
//
int32_t spoofDataLength = ds->readUInt32(spoofDH->fLength);
int32_t totalSize = headerSize + spoofDataLength;
if (length < 0) {
return totalSize;
}
//
// Check that length passed in is consistent with length from Spoof data header.
//
if (length < totalSize) {
udata_printError(ds, "uspoof_swap(): too few bytes (%d after ICU Data header) for spoof data.\n",
spoofDataLength);
*status=U_INDEX_OUTOFBOUNDS_ERROR;
return 0;
}
//
// Swap the Data. Do the data itself first, then the Spoof Data Header, because
// we need to reference the header to locate the data, and an
// inplace swap of the header leaves it unusable.
//
uint8_t *outBytes = (uint8_t *)outData + headerSize;
SpoofDataHeader *outputDH = (SpoofDataHeader *)outBytes;
int32_t sectionStart;
int32_t sectionLength;
//
// If not swapping in place, zero out the output buffer before starting.
// Gaps may exist between the individual sections, and these must be zeroed in
// the output buffer. The simplest way to do that is to just zero the whole thing.
//
if (inBytes != outBytes) {
uprv_memset(outBytes, 0, spoofDataLength);
}
// Confusables Keys Section (fCFUKeys)
sectionStart = ds->readUInt32(spoofDH->fCFUKeys);
sectionLength = ds->readUInt32(spoofDH->fCFUKeysSize) * 4;
ds->swapArray32(ds, inBytes+sectionStart, sectionLength, outBytes+sectionStart, status);
// String Index Section
sectionStart = ds->readUInt32(spoofDH->fCFUStringIndex);
sectionLength = ds->readUInt32(spoofDH->fCFUStringIndexSize) * 2;
ds->swapArray16(ds, inBytes+sectionStart, sectionLength, outBytes+sectionStart, status);
// String Table Section
sectionStart = ds->readUInt32(spoofDH->fCFUStringTable);
sectionLength = ds->readUInt32(spoofDH->fCFUStringTableLen) * 2;
ds->swapArray16(ds, inBytes+sectionStart, sectionLength, outBytes+sectionStart, status);
// String Lengths Section
sectionStart = ds->readUInt32(spoofDH->fCFUStringLengths);
sectionLength = ds->readUInt32(spoofDH->fCFUStringLengthsSize) * 4;
ds->swapArray16(ds, inBytes+sectionStart, sectionLength, outBytes+sectionStart, status);
// Any Case Trie
sectionStart = ds->readUInt32(spoofDH->fAnyCaseTrie);
sectionLength = ds->readUInt32(spoofDH->fAnyCaseTrieLength);
utrie2_swap(ds, inBytes+sectionStart, sectionLength, outBytes+sectionStart, status);
// Lower Case Trie
sectionStart = ds->readUInt32(spoofDH->fLowerCaseTrie);
sectionLength = ds->readUInt32(spoofDH->fLowerCaseTrieLength);
utrie2_swap(ds, inBytes+sectionStart, sectionLength, outBytes+sectionStart, status);
// Script Sets. The data is an array of int32_t
sectionStart = ds->readUInt32(spoofDH->fScriptSets);
sectionLength = ds->readUInt32(spoofDH->fScriptSetsLength) * 4;
ds->swapArray32(ds, inBytes+sectionStart, sectionLength, outBytes+sectionStart, status);
// And, last, swap the header itself.
// int32_t fMagic // swap this
// uint8_t fFormatVersion[4] // Do not swap this
// int32_t all the rest // Swap the rest, all is 32 bit stuff.
//
uint32_t magic = ds->readUInt32(spoofDH->fMagic);
ds->writeUInt32((uint32_t *)&outputDH->fMagic, magic);
ds->swapArray32(ds, &spoofDH->fLength, sizeof(SpoofDataHeader)-8, &outputDH->fLength, status);
return totalSize;
}