throw new IOException("corrupted stream - high tag number < 31 found");
            }

            tagNo = b & 0x7f;

            // X.690-0207 8.1.2.4.2
            // "c) bits 7 to 1 of the first subsequent octet shall not all be zero."
            if (0 == tagNo)
            {
                throw new IOException("corrupted stream - invalid high tag number found");
            }