Need to parse binary ASN.1 BER .Please suggest to do in Apache NIFI.
I see that there are some linux packages available to parse this. Quick search showed there are different tools that are available. If you can use them to parse this data outside nifi, you can use ExecuteProcess to call that executable.
Alternatively, I see https://www.openmuc.org/asn1/ which is a java API. You can use that and write a custom processor in Nifi.