This file contains release notes on the ASN1DECODER 2.8 release.



ASN1DECODER (ASN.1 to text decoder) is a statically-linked command-line application that is used to translate binary data encoded using various ASN.1 encoding rules (BER/CER/DER and PER/UPER) to text-based XML or JSON output formats.

Release Notes

ASN1DECODER now follows ITU-T X.697 JSON Encoding Rules (JER). Previously, it followed proprietary rules developed by Objective Systems. These rules, and their differences from X.697, are discussed in our paper, Javascript Object Notation (JSON) Encoding Rules for ASN.1

Users are encouraged to consult the documentation in the doc subdirectory for information regarding the transformation of binary input files into output textual formats.

Up-to-date change log information for future releases will be made available on our website.


Documentation for this release is provided in the doc subdirectory of the installation.

Windows Installation

The steps to install ASN1DECODER on a Windows system are as follows:

  1. Download the ASN1DECODER package distribution file.
  2. ASN1DECODER for Windows is packaged in a self-extracting executable file format. To install, all that should be necessary is to double-click this file after downloading and then following the setup wizard instructions.

An osyslic.txt license is necessary to enable the product to run. This should have been sent as an attachment in an E-mail message or should be available on the user's product download web page. Copy this file into the 'bin' subdirectory of the asn1dec installation.

ASN1DECODER should now be operational. Refer to the ASN1DECODER User's Guide document in the doc subdirectory for instructions on how to run the program.

Contents of the Release

The following subdirectories contain the following files (note: <installdir> refers to the installation directory that was specified during the installation process):
The asn1decoder command-line program executable file.
This directory contains the ASN1DECODER User's Guide file asn1dec.pdf file.
This directory contains a collection of common ASN.1 specification files from existing standards that have been used with the tool.
This directory contains sample programs containing encoded BER/DER message files (these files have a '.dat' or '.bin' extension) and corresponding ASN.1 schema files (these have extension '.asn'). ASN1DECODER can be used to translate these files to text formats. A perl script ( is provided to test the translation of all files to text formats.
This directory contains sample data containing PER message files and corresponding ASN.1 schema files. ASN1DECODER can be used to translate these files to XML. A Perl script,, is provided for this purpose.

Reporting Problems

Report problems you encounter by sending E-mail to The preferred format of example programs is the same as the sample programs. Please provide a message file and an ASN.1 syntax file and also indicate where the problem occurs.

If you have any further questions or comments on what you would like to see in the product or what is difficult to use or understand, please communicate them to us. Your feedback is important to us.