Some ISO ASN.1 standards (unfortunately not ISO 8824 and 8825) can be downloaded for free from https://standards.iso.org/ittf/PubliclyAvailableStandards/.
Re:Useful Old Technologies: ASN.1 (2013)
by XAMPPRocky on Sunday December 26, 2021 @01:29PM
(#29694991)
All standards about ASN.1 (not including standards that use ASN.1 like MMS) are available for free from the ITU under the X.680 to X.697 series of standards.[0]
- ASN.1 Communication between Heterogeneous Systems[0]
- ASN.1 Complete[1]
Both of which are available online for free. Last time I checked, they may not cover the latest fads like JER etc. but will provide you with a solid understanding of ASN.1 nonetheless.
[0] https://www.oss.com/asn1/resources/books-whitepapers-pubs/la... [1] https://www.oss.com/asn1/resources/books-whitepapers-pubs/du...