int ftag = in.read();
        int tag = readTagNumber(in, ftag);
        if ( tag != expectTag ) {
            throw new IOException("Unexpected tag " + tag);
        }
        int length = readLength(in, limit, false);
        byte[] content = new byte[length];
        in.read(content);
        return content;
    }

    // shamelessly stolen from BC ASN1InputStream