int read_encrypted_file(fz_stream *stm, unsigned char *buf, int len){
	int n=0;
	rimage_aesd *aesd = (rimage_aesd *)stm->state;//get aesd from stm

	int64_t toPos;//position to read to from decryptedBuffer
	int64_t fromPos;//position to read from in decrypted buffer
	int whence = 0;
	int whence1 = 0;
	int lastSeekPos = stm->pos;
	int64_t blockStartPoint = 0;
	int64_t block_num = findBlocNum(stm->pos);//depending on the fileHandler position

	blockStartPoint = block_num*BLOCK_SIZE;

	aesd->blockNum = block_num;
	fromPos = stm->pos - blockStartPoint;
	toPos = fromPos + len;
	if(lastSeekPos > aesd->contentSize){
		//return -1;
	}
	whence = stm->pos - blockStartPoint;
	//lseek(aesd->filehandle, 1, -whence);//seek to block start to read data
	lseek(aesd->filehandle, 0, blockStartPoint);

	read(aesd->filehandle, aesd->encryptedBuffer, BLOCK_SIZE);
	rimage_decrypt_block(aesd);
	//to handle scenario where some data is in this block and remaining in next block
	if(toPos > BLOCK_SIZE){
		n += copy_decrypted_data(buf,aesd,fromPos,BLOCK_SIZE,n);
		aesd->blockNum++;
		read(aesd->filehandle, aesd->encryptedBuffer, BLOCK_SIZE);
		rimage_decrypt_block(aesd);
		toPos = len - n;
		fromPos = 0;

		if( (aesd->blockNum * BLOCK_SIZE) + toPos > aesd->contentSize){
			toPos = toPos - ((aesd->blockNum * BLOCK_SIZE) + toPos - aesd->contentSize);
		}
	}else{
		if(lastSeekPos+len > aesd->contentSize){
			toPos = toPos - (lastSeekPos+len - aesd->contentSize);

		}
	}

	n += copy_decrypted_data(buf,aesd,fromPos,toPos,n);

	whence = lastSeekPos + n;
	lseek(aesd->filehandle, 0, whence);//set file handle position correctly
	fz_assert_lock_held(stm->ctx, FZ_LOCK_FILE);
	if (n < 0)
		fz_throw(stm->ctx, "read error: %s", strerror(errno));
	return n;
 }