asn1parse

 

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 ASN1PARSE(1)                 OpenSSL                 ASN1PARSE(1)
 
 
 
 NAME
        asn1parse - ASN.1 parsing tool
 
 SYNOPSIS
        openssl asn1parse [-inform PEM|DER] [-in filename] [-out
        filename] [-noout] [-offset number] [-length number] [-i]
        [-oid filename] [-strparse offset]
 
 DESCRIPTION
        The asn1parse command is a diagnostic utility that can
        parse ASN.1 structures. It can also be used to extract
        data from ASN.1 formatted data.
 
 OPTIONS
        -inform DER|PEM
            the input format. DER is binary format and PEM (the
            default) is base64 encoded.
 
        -in filename
            the input file, default is standard input
 
        -out filename
            output file to place the DER encoded data into. If
            this option is not present then no data will be
            output. This is most useful when combined with the
            -strparse option.
 
        -noout
            don't output the parsed version of the input file.
 
        -offset number
            starting offset to begin parsing, default is start of
            file.
 
        -length number
            number of bytes to parse, default is until end of
            file.
 
        -i  indents the output according to the "depth" of the
            structures.
 
        -oid filename
            a file containing additional OBJECT IDENTIFIERs
            (OIDs). The format of this file is described in the
            NOTES section below.
 
        -strparse offset
            parse the contents octets of the ASN.1 object starting
            at offset. This option can be used multiple times to
            "drill down" into a nested structure.
 
        OUTPUT
 
        The output will typically contain lines like this:
 
          0:d=0  hl=4 l= 681 cons: SEQUENCE
 
        .....
 
 
 
 
          229:d=3  hl=3 l= 141 prim: BIT STRING
          373:d=2  hl=3 l= 162 cons: cont [ 3 ]
          376:d=3  hl=3 l= 159 cons: SEQUENCE
          379:d=4  hl=2 l=  29 cons: SEQUENCE
          381:d=5  hl=2 l=   3 prim: OBJECT            :X509v3 Subject Key Identifier
          386:d=5  hl=2 l=  22 prim: OCTET STRING
          410:d=4  hl=2 l= 112 cons: SEQUENCE
          412:d=5  hl=2 l=   3 prim: OBJECT            :X509v3 Authority Key Identifier
          417:d=5  hl=2 l= 105 prim: OCTET STRING
          524:d=4  hl=2 l=  12 cons: SEQUENCE
 
        .....
 
        This example is part of a self signed certificate. Each
        line starts with the offset in decimal. d=XX specifies the
        current depth. The depth is increased within the scope of
        any SET or SEQUENCE. hl=XX gives the header length (tag
        and length octets) of the current type. l=XX gives the
        length of the contents octets.
 
        The -i option can be used to make the output more
        readable.
 
        Some knowledge of the ASN.1 structure is needed to
        interpret the output.
 
        In this example the BIT STRING at offset 229 is the
        certificate public key.  The contents octets of this will
        contain the public key information. This can be examined
        using the option -strparse 229 to yield:
 
            0:d=0  hl=3 l= 137 cons: SEQUENCE
            3:d=1  hl=3 l= 129 prim: INTEGER           :E5D21E1F5C8D208EA7A2166C7FAF9F6BDF2059669C60876DDB70840F1A5AAFA59699FE471F379F1DD6A487E7D5409AB6A88D4A9746E24B91D8CF55DB3521015460C8EDE44EE8A4189F7A7BE77D6CD3A9AF2696F486855CF58BF0EDF2B4068058C7A947F52548DDF7E15E96B385F86422BEA9064A3EE9E1158A56E4A6F47E5897
          135:d=1  hl=2 l=   3 prim: INTEGER           :010001
 
 
 NOTES
        If an OID is not part of OpenSSL's internal table it will
        be represented in numerical form (for example 1.2.3.4).
        The file passed to the -oid option allows additional OIDs
        to be included. Each line consists of three columns, the
        first column is the OID in numerical format and should be
        followed by white space. The second column is the "short
        name" which is a single word followed by white space. The
        final column is the rest of the line and is the "long
        name". asn1parse displays the long name. Example:
 
        1.2.3.4   shortName A long name
 
 BUGS
        There should be options to change the format of input
        lines. The output of some ASN.1 types is not well handled
        (if at all).
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 20/Jan/2000                   0.9.6b                 ASN1PARSE(1)

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