Question on ASN.1 Encodings

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#673

From: Steve Case
Date: Wed, 11 Nov 1992 17:13

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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

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From: scase@email.sp.paramax.com (Steve Case)
Newsgroups: comp.protocols.iso.dev-environ
Subject: Question on ASN.1 Encodings
Message-ID: <1drf0lINN8up@svcase.sp.paramax.com>
Date: 11 Nov 92 17:13:57 GMT
Organization: Paramax -  Eagan, MN
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