asn1parse(1)

     ASN1PARSE(1)           0.9.6h (2000-01-20)           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.

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          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:

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          "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).

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