Assigning a Built-in ASN.1 Schema to a Message
Built-in ASN.1 schemas are groups of ASN.1 schema files that
make up well-known standards. Components (or modules) that
make make up the complete schema for a particular standard
may be spread across multiple domains. Built-in schemas
consolidate this information into a single named item -
typically a directory on the system containing the base
schema files and a special configuration file describing
how imports within those schemas should be resolved.
A built-in ASN.1 schema may be assigned (associated) with a
BER, DER, or CER ASN.1 message by using this command.
ASN.1 built-in schema are assigned to PER messages when they
are created or opened because they are required to understand
the content of the message. Assigning an ASN.1 schema
will provide symbolic element names and type information for
the content items within the message. It will also enable the
editing of fields within the message.
1. Click the Assign option from the main
menu toolbar.
2. Select the Built-in ASN.1 Schema(s)
option to open the built-in ASN.1 schemas dialog.
3. The built-in ASN.1 schema dialog box will be displayed
allowing the selection of a built-in schema.
4. After successful compilation of the ASN.1 file(s):
If a single matching PDU type is found in the schema
that matches the current message being displayed,
then ASN1VE will decode the message using the matched
PDU type and the view will be switched to element
view completing this operation.
5. If multiple matching PDU types are found, then
ASN1VE will prompt the user to select a PDU type using
the Select PDU type dialog:
Display Possible PDU Types and
Display All Types radio boxes will
be displayed with the list of module names in the selected
ASN.1 specifications. Each module will contain a list
of type names in that module.
The Display Possible
PDU Types button selection will show only those
types that are most likely to be used for a new message.
This is defined to be all types in the module that are
not referenced by any other types and which match the initial
tag on the message. If no types meet this
criteria, then no types will be displayed in this list.
The Display All Types selection will display
all of the types for each module.
6. If the user selects a type and presses OK,
ASN1VE will try to decode the message with the user-selected
PDU type and the view will be switched to element view if
decoding is successful. The user may also press the
Cancel button at this point to cancel the
operation.
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