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ASN1PARSE(1)			    OpenSSL			  ASN1PARSE(1)

       asn1parse - ASN.1 parsing tool

       openssl asn1parse [-inform PEM|DER] [-in	filename] [-out	filename]
       [-noout]	[-offset number] [-length number] [-i] [-oid filename] [-str-
       parse offset]

       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

       -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.

	   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.


       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	out-

       In this example the BIT STRING at offset	229 is the certificate public
       key.  The contents octets of this will contain the public key informa-
       tion. 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

       If an OID is not	part of	OpenSSL's internal table it will be repre-
       sented in numerical form	(for example 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:

       "	 shortName A long name"

       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).

0.9.7d				  2005-02-25			  ASN1PARSE(1)


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