ASN.1 protocol specification for use with arbitrary encoding schemes

摘要

Abstract Syntax Notation One (ASN.1) is a language for describing structured information. It is generally used in the specification of communications protocols. To date, it has primarily been used in the specification of OSI application layer protocols and protocols which use basic encoding rules (BER) and its derivatives as encoding schemes. While it is difficult to understand why ASN.1 has not received more widespread use for protocol specification, one possible explanation is its perceived reliance on BER and its derivatives as encoding schemes. This work attempts to address this misconception by providing mappings for ASN.1 constructs directly onto encoding schemes other than BER. By harnessing the techniques described, ASN.1 can be used to describe new and existing protocols regardless of their encoding scheme. The effectiveness of our techniques is demonstrated using a protocol analyzer (sometimes called a packet analyzer). Protocol analyzers decode and display protocol data units (PDUs). A major limitation of many protocol analyzers is their inability to dynamically incorporate new and proprietary PDUs. A "proof of concept" for the solutions suggested in this paper is provided via a protocol analyzer capable of processing protocols directly from an ASN.1 specification.