$ fq -h asn1_ber
asn1_ber: ASN1 BER (basic encoding rules, also CER and DER) decoder

Decode examples
===============

  # Decode file as asn1_ber
  $ fq -d asn1_ber . file
  # Decode value as asn1_ber
  ... | asn1_ber

Supports decoding BER, CER and DER (X.690).

- Currently no extra validation is done for CER and DER.
- Does not support specifying a schema.
- Supports torepr but without schema all sequences and sets will be arrays.

Can be used to decode certificates etc
======================================
  $ fq -d bytes 'from_pem | asn1_ber | d' cert.pem

Can decode nested values
========================
  $ fq -d asn1_ber '.constructed[1].value | asn1_ber' file.ber

Manual schema
=============
  $ fq -d asn1_ber 'torepr as $r | ["version", "modulus", "private_exponent", "private_exponen", "prime1", "prime2", "exponent1", "exponent2", "coefficient"] | with_entries({key: .value, value: $r[.key]})' pkcs1.der

References
==========
- https://www.itu.int/ITU-T/studygroups/com10/languages/X.690_1297.pdf
- https://en.wikipedia.org/wiki/X.690
- https://letsencrypt.org/docs/a-warm-welcome-to-asn1-and-der/
- https://lapo.it/asn1js/