3.2 Invoking asn1Coding

asn1Coding generates a DER encoding from a file with ASN.1 definitions and another one with assignments.

The file with assignments must have this syntax:

InstanceName  Asn1Definition

nameString  value

nameString  value
...

To specify the field of a CHOICE to be used, specify its name as a value to the CHOICE element itself. Use '' to denote the root element itself. (as in the example below.)

The output file is a binary file with the DER encoding.

Usage:  asn1Coding [options] file1 file2
 file1 : file with ASN1 definitions.
 file2 : file with assignments.
Options:
 -h : shows the help message.
 -v : shows version information and exit.
 -c : checks the syntax only.
 -o file : output file.

For example, consider an ASN.1 definitions file as follows:

PKIX1 { }

DEFINITIONS IMPLICIT TAGS ::=

BEGIN

Dss-Sig-Value ::= SEQUENCE {
     r       INTEGER,
     s       INTEGER
}

END

And a assignments file as follows:

dp PKIX1.Dss-Sig-Value

r 42
s 47

Running the command below will generate a assign.out file, containing the DER encoding of PKIX1.Dss-Sig-Value.

$ asn1Coding pkix.asn assign.asn1

If the root element is of the CHOICE type, the assignment file may be like (using the types defined in pkix.asn):

elt PKIX1Implicit88.GeneralName

''      dNSName
dNSName example.org