REQUIREMENTS

Erlang (http://www.erlang.org) needs to be installed on your system

BUILD INSTRUCTION

UNIX

make; sudo make install

WINDOWS

install.bat

DECODING A FILE

Select the ASN.1 specification you expect the file to be encoded with
Select a file to encode

The tool consists of several elements:

Select already imported ASN.1 Specification used for decoding the file
Tree list showing all parts in the decoded file
A textual representation of the decoded file closely following the ASN.1 specification
An XML view of the decoded data
An Hex view of the raw data.
Info text field

Any messages will be shown in the info text field (5)

Editing (not working yet)

Changes can be made in the tree list and when saved will be reflected in the other views. The tool will only check if any changes are valid ASN.1 and you will have to make sure that any changes are correctly formed, e.g. in the case of an AddressString, the tool can only check that it is a string of Octets, the actual meaning of the octets is not know to the tool.

Importing ASN.1 Specification

Select ASN.1 specification. If your specification is broken up in several parts, you need to provide a "set" file listing all parts. This is typically the case when the ASN.1 specification contains IMPORT statements
Provide a title used in the dropdown list
Provide a version (in order to distinguish multiple version of the spec)
Indicate the encoding rules used. If you don't know use 'ber'.

If you get this error:

Compiling asn.1 specification: filename
got 'EXPLICIT' expected one of: 'typereference . typereference', typereference, 
    'TYPE-IDENTIFIER' or 'ABSTRACT-SYNTAX'

This is caused by a wrong use of the EXPLICIT statement. To solve this make sure to remove EXPLICIT in the tag assignment and add the EXPLICIT where-ever the tag is referenced.

EXAMPLE

Look for a tag that is tagged EXPLICIT like this

 GSNAddress ::= EXPLICIT IPBinaryAddress

 :
 
 ServingElement ::= CHOICE {
	originInfo                 [0] OriginInfo,
	mSCAddress                 [1] AddressString,
	ggsnAddress                [2] GSNAddress,
	sgsnAddress                [3] GSNAddress,
	...
}

Remove the EXPLICIT keyword and add it in front of tag when referenced

 GSNAddress ::= IPBinaryAddress

 :
 
 ServingElement ::= CHOICE {
	originInfo                 [0] OriginInfo,
	mSCAddress                 [1] AddressString,
	ggsnAddress                [2] EXPLICIT GSNAddress,
	sgsnAddress                [3] EXPLICIT GSNAddress,
	...
}

and it will work.

amaamb / easn