private void readInternal(ByteBuffer dst, long position, int len) throws IOException {
int x = dst.position();
readFully(base, position + HEADER_LENGTH, dst);
long block = position / BLOCK_SIZE;
while (len > 0) {
xts.decrypt(block++, BLOCK_SIZE, dst.array(), dst.arrayOffset() + x);
x += BLOCK_SIZE;
len -= BLOCK_SIZE;
}
}
private void writeInternal(ByteBuffer src, long position, int len) throws IOException {
ByteBuffer crypt = ByteBuffer.allocate(len);
crypt.put(src);
crypt.flip();
long block = position / BLOCK_SIZE;
int x = 0, l = len;
while (l > 0) {
xts.encrypt(block++, BLOCK_SIZE, crypt.array(), crypt.arrayOffset() + x);
x += BLOCK_SIZE;
l -= BLOCK_SIZE;
}
writeFully(base, position + HEADER_LENGTH, crypt);
}