InputStream s = new ByteArrayInputStream(new byte[] {});
        assertThrows(EOFException.class, () -> {
            ASN1Util.readLength(s, 100, false);
        });
    }

    @Test
    void testReadLength_OutOfBounds() {
        // Length out of bounds
        InputStream s = new ByteArrayInputStream(new byte[] { (byte) 0x81, (byte) 0xFF }); // length 255
        assertThrows(IOException.class, () -> {