🚀 go-pugleaf

In <1drej9INN8t8@svcase.sp.paramax.com> Steve Case writes:
>I am trying to understand the various ASN.1 encoding and I cannot seem
>to understand how the indefinite form for the length octets can possibly
>work!  To make things simple, let me give you a specific example and
>hopefully someone can clarify the situation for me.
>
>Let's assume we are encoding a bitstring value.  The particular bitstring
>to be encoded is '0900000009'H.  If I use the indefinite length format,
>wouldn't this be encoded as follows:
>
>   BitString Length Contents
>   23        80     000900000009
>
>   EOC       Length
>   00        00
>
>My question, then, is when decoding this octet stream, how do you know
>that the bitstring is '0900000009'H and not '09'H or '090'H or '0900'H
>or '09000'H?  All three of these seem to be possible decodings?
>
>Thank you for any assistance you might be able to give me.
>
>Regards,
>Steve Case
>scase@planet8.sp.paramax.com
>
Indefinite length encoding may only be used when the contents are
constructed.  Your example uses the primitive encoding form for
BIT STRING.

Mike Gering
IBM
Dept. E78, Building 673
RTP, NC 27709