WOFFFileFormat.cpp [plain text]
#include "config.h"
#include "WOFFFileFormat.h"
#include <zlib.h>
#include "SharedBuffer.h"
#include <wtf/ByteOrder.h>
#if USE(WOFF2)
#include "woff2_common.h"
#include "woff2_dec.h"
#endif
namespace WebCore {
static bool readUInt32(SharedBuffer& buffer, size_t& offset, uint32_t& value)
{
ASSERT_ARG(offset, offset <= buffer.size());
if (buffer.size() - offset < sizeof(value))
return false;
value = ntohl(*reinterpret_cast_ptr<const uint32_t*>(buffer.data() + offset));
offset += sizeof(value);
return true;
}
static bool readUInt16(SharedBuffer& buffer, size_t& offset, uint16_t& value)
{
ASSERT_ARG(offset, offset <= buffer.size());
if (buffer.size() - offset < sizeof(value))
return false;
value = ntohs(*reinterpret_cast_ptr<const uint16_t*>(buffer.data() + offset));
offset += sizeof(value);
return true;
}
static bool writeUInt32(Vector<char>& vector, uint32_t value)
{
uint32_t bigEndianValue = htonl(value);
return vector.tryAppend(reinterpret_cast_ptr<char*>(&bigEndianValue), sizeof(bigEndianValue));
}
static bool writeUInt16(Vector<char>& vector, uint16_t value)
{
uint16_t bigEndianValue = htons(value);
return vector.tryAppend(reinterpret_cast_ptr<char*>(&bigEndianValue), sizeof(bigEndianValue));
}
static const uint32_t woffSignature = 0x774f4646;
bool isWOFF(SharedBuffer& buffer)
{
size_t offset = 0;
uint32_t signature;
if (!readUInt32(buffer, offset, signature))
return false;
#if USE(WOFF2)
return signature == woffSignature || signature == woff2::kWoff2Signature;
#else
return signature == woffSignature;
#endif
}
bool convertWOFFToSfnt(SharedBuffer& woff, Vector<char>& sfnt)
{
ASSERT_ARG(sfnt, sfnt.isEmpty());
size_t offset = 0;
uint32_t signature;
if (!readUInt32(woff, offset, signature)) {
ASSERT_NOT_REACHED();
return false;
}
#if USE(WOFF2)
if (signature == woff2::kWoff2Signature) {
const uint8_t* woffData = reinterpret_cast_ptr<const uint8_t*>(woff.data());
const size_t woffSize = woff.size();
const size_t sfntSize = woff2::ComputeWOFF2FinalSize(woffData, woffSize);
if (!sfnt.tryReserveCapacity(sfntSize))
return false;
sfnt.resize(sfntSize);
return woff2::ConvertWOFF2ToTTF(reinterpret_cast<uint8_t*>(sfnt.data()), sfnt.size(), woffData, woffSize);
}
#endif
if (signature != woffSignature) {
ASSERT_NOT_REACHED();
return false;
}
uint32_t flavor;
if (!readUInt32(woff, offset, flavor))
return false;
uint32_t length;
if (!readUInt32(woff, offset, length) || length != woff.size())
return false;
uint16_t numTables;
if (!readUInt16(woff, offset, numTables))
return false;
if (!numTables || numTables > 0x0fff)
return false;
uint16_t reserved;
if (!readUInt16(woff, offset, reserved) || reserved)
return false;
uint32_t totalSfntSize;
if (!readUInt32(woff, offset, totalSfntSize))
return false;
if (woff.size() - offset < sizeof(uint16_t) + sizeof(uint16_t) + sizeof(uint32_t) + sizeof(uint32_t) + sizeof(uint32_t) + sizeof(uint32_t) + sizeof(uint32_t))
return false;
offset += sizeof(uint16_t); offset += sizeof(uint16_t); offset += sizeof(uint32_t); offset += sizeof(uint32_t); offset += sizeof(uint32_t); offset += sizeof(uint32_t); offset += sizeof(uint32_t);
if (woff.size() - offset < numTables * 5 * sizeof(uint32_t))
return false;
uint16_t entrySelector = 0;
uint16_t searchRange = 1;
while (searchRange < numTables >> 1) {
entrySelector++;
searchRange <<= 1;
}
searchRange <<= 4;
uint16_t rangeShift = (numTables << 4) - searchRange;
if (!writeUInt32(sfnt, flavor)
|| !writeUInt16(sfnt, numTables)
|| !writeUInt16(sfnt, searchRange)
|| !writeUInt16(sfnt, entrySelector)
|| !writeUInt16(sfnt, rangeShift))
return false;
if (sfnt.size() > totalSfntSize)
return false;
if (totalSfntSize - sfnt.size() < numTables * 4 * sizeof(uint32_t))
return false;
size_t sfntTableDirectoryCursor = sfnt.size();
sfnt.grow(sfnt.size() + numTables * 4 * sizeof(uint32_t));
for (uint16_t i = 0; i < numTables; ++i) {
uint32_t tableTag;
if (!readUInt32(woff, offset, tableTag))
return false;
uint32_t tableOffset;
if (!readUInt32(woff, offset, tableOffset))
return false;
uint32_t tableCompLength;
if (!readUInt32(woff, offset, tableCompLength))
return false;
if (tableOffset > woff.size() || tableCompLength > woff.size() - tableOffset)
return false;
uint32_t tableOrigLength;
if (!readUInt32(woff, offset, tableOrigLength) || tableCompLength > tableOrigLength)
return false;
if (tableOrigLength > totalSfntSize || sfnt.size() > totalSfntSize - tableOrigLength)
return false;
uint32_t tableOrigChecksum;
if (!readUInt32(woff, offset, tableOrigChecksum))
return false;
uint32_t* sfntTableDirectoryPtr = reinterpret_cast_ptr<uint32_t*>(sfnt.data() + sfntTableDirectoryCursor);
*sfntTableDirectoryPtr++ = htonl(tableTag);
*sfntTableDirectoryPtr++ = htonl(tableOrigChecksum);
*sfntTableDirectoryPtr++ = htonl(sfnt.size());
*sfntTableDirectoryPtr++ = htonl(tableOrigLength);
sfntTableDirectoryCursor += 4 * sizeof(uint32_t);
if (tableCompLength == tableOrigLength) {
if (!sfnt.tryAppend(woff.data() + tableOffset, tableCompLength))
return false;
} else {
uLongf destLen = tableOrigLength;
if (!sfnt.tryReserveCapacity(sfnt.size() + tableOrigLength))
return false;
Bytef* dest = reinterpret_cast<Bytef*>(sfnt.end());
sfnt.grow(sfnt.size() + tableOrigLength);
if (uncompress(dest, &destLen, reinterpret_cast<const Bytef*>(woff.data() + tableOffset), tableCompLength) != Z_OK)
return false;
if (destLen != tableOrigLength)
return false;
}
while (sfnt.size() % 4)
sfnt.append(0);
}
return sfnt.size() == totalSfntSize;
}
}