ASN1PARSE(1) OpenSSL ASN1PARSE(1)

NAME
       asn1parse - ASN.1 parsing tool

SYNOPSIS
       ooppeennssssll aassnn11ppaarrssee [-iinnffoorrmm PPEEMM||DDEERR] [-iinn ffiilleennaammee] [-oouutt ffiilleennaammee]
       [-nnoooouutt] [-ooffffsseett nnuummbbeerr] [-lleennggtthh nnuummbbeerr] [-ii] [-ooiidd ffiilleennaammee]
       [-ssttrrppaarrssee ooffffsseett]

DESCRIPTION
       The aassnn11ppaarrssee command is a diagnostic utility that can parse ASN.1
       structures. It can also be used to extract data from ASN.1 formatted
       data.

OOPPTTIIOONNSS
       -iinnffoorrmm DDEERR||PPEEMM
           the input format. DDEERR is binary format and PPEEMM (the default) is
           base64 encoded.

       -iinn ffiilleennaammee
           the input file, default is standard input

       -oouutt ffiilleennaammee
           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 -ssttrrppaarrssee option.

       -nnoooouutt
           don't output the parsed version of the input file.

       -ooffffsseett nnuummbbeerr
           starting offset to begin parsing, default is start of file.

       -lleennggtthh nnuummbbeerr
           number of bytes to parse, default is until end of file.

       -ii  indents the output according to the "depth" of the structures.

       -ooiidd ffiilleennaammee
           a file containing additional OBJECT IDENTIFIERs (OIDs). The format
           of this file is described in the NOTES section below.

       -ssttrrppaarrssee ooffffsseett
           parse the contents octets of the ASN.1 object starting at ooffffsseett.
           This option can be used multiple times to "drill down" into a
           nested structure.

       OOUUTTPPUUTT

       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. dd==XXXX specifies the current depth. The depth
       is increased within the scope of any SET or SEQUENCE. hhll==XXXX gives the
       header length (tag and length octets) of the current type. ll==XXXX gives
       the length of the contents octets.

       The -ii 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 -ssttrrppaarrssee 222299 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

NNOOTTEESS
       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 -ooiidd 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". aassnn11ppaarrssee
       displays the long name. Example:

       "1.2.3.4  shortName A long name"

BUGS
       There should be options to change the format of output lines. The
       output of some ASN.1 types is not well handled (if at all).



0.9.7l                            2004-11-25                      ASN1PARSE(1)