bool inflateZlibInstallShield(byte *dst, uint dstLen, const byte *src, uint srcLen) {
if (!dst || !dstLen || !src || !srcLen)
return false;
// See if we have sync bytes. If so, just use our function for that.
if (srcLen >= 4 && READ_BE_UINT32(src + srcLen - 4) == 0xFFFF)
return inflateZlibHeaderless(dst, dstLen, src, srcLen);
// Otherwise, we have some custom code we get to use here.
byte *temp = (byte *)malloc(kTempBufSize);
uint32 bytesRead = 0, bytesProcessed = 0;
while (bytesRead < srcLen) {
uint16 chunkSize = READ_LE_UINT16(src + bytesRead);
bytesRead += 2;
// Initialize zlib
z_stream stream;
stream.next_in = const_cast<byte *>(src + bytesRead);
stream.avail_in = chunkSize;
stream.next_out = temp;
stream.avail_out = kTempBufSize;
stream.zalloc = Z_NULL;
stream.zfree = Z_NULL;
stream.opaque = Z_NULL;
// Negative MAX_WBITS tells zlib there's no zlib header
int err = inflateInit2(&stream, -MAX_WBITS);
if (err != Z_OK)
return false;
err = inflate(&stream, Z_FINISH);
if (err != Z_OK && err != Z_STREAM_END) {
inflateEnd(&stream);
free(temp);
return false;
}
memcpy(dst + bytesProcessed, temp, stream.total_out);
bytesProcessed += stream.total_out;
inflateEnd(&stream);
bytesRead += chunkSize;
}
free(temp);
return true;
}
uint32 CdfArchive::BlockDecode(uint8 *dst, uint32 a_dst_size, const uint8 *a_src, uint32 a_src_size) const
{
uint32 dst_size = 0;
uint16 data_type = READ_LE_UINT16(a_src);
const uint8 *src = a_src + sizeof(uint16);
uint32 src_size = a_src_size - sizeof(uint16);
// data uncompressed, just copy contents
if(data_type == 0)
{
memcpy(dst, src, src_size);
dst_size = src_size;
}
// deflate compression used
else if(data_type == 8)
dst_size = inflateZlibHeaderless((byte *)dst, a_dst_size, src, src_size);
return dst_size;
}
