name : openssl-asn1parse.1ssl .\" Automatically generated by Pod::Man 4.11 (Pod::Simple 3.35) .\" .\" Standard preamble: .\" ======================================================================== .de Sp \" Vertical space (when we can't use .PP) .if t .sp .5v .if n .sp .. .de Vb \" Begin verbatim text .ft CW .nf .ne \\$1 .. .de Ve \" End verbatim text .ft R .fi .. .\" Set up some character translations and predefined strings. \*(-- will .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left .\" double quote, and \*(R" will give a right double quote. \*(C+ will .\" give a nicer C++. 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Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .if n .ad l .nh .SH "NAME" openssl\-asn1parse, asn1parse \- ASN.1 parsing tool .SH "SYNOPSIS" .IX Header "SYNOPSIS" \&\fBopenssl\fR \fBasn1parse\fR [\fB\-help\fR] [\fB\-inform PEM|DER\fR] [\fB\-in filename\fR] [\fB\-out filename\fR] [\fB\-noout\fR] [\fB\-offset number\fR] [\fB\-length number\fR] [\fB\-i\fR] [\fB\-oid filename\fR] [\fB\-dump\fR] [\fB\-dlimit num\fR] [\fB\-strparse offset\fR] [\fB\-genstr string\fR] [\fB\-genconf file\fR] [\fB\-strictpem\fR] [\fB\-item name\fR] .SH "DESCRIPTION" .IX Header "DESCRIPTION" The \fBasn1parse\fR command is a diagnostic utility that can parse \s-1ASN.1\s0 structures. It can also be used to extract data from \s-1ASN.1\s0 formatted data. .SH "OPTIONS" .IX Header "OPTIONS" .IP "\fB\-help\fR" 4 .IX Item "-help" Print out a usage message. .IP "\fB\-inform\fR \fBDER|PEM\fR" 4 .IX Item "-inform DER|PEM" The input format. \fB\s-1DER\s0\fR is binary format and \fB\s-1PEM\s0\fR (the default) is base64 encoded. .IP "\fB\-in filename\fR" 4 .IX Item "-in filename" The input file, default is standard input. .IP "\fB\-out filename\fR" 4 .IX Item "-out filename" Output file to place the \s-1DER\s0 encoded data into. If this option is not present then no data will be output. This is most useful when combined with the \fB\-strparse\fR option. .IP "\fB\-noout\fR" 4 .IX Item "-noout" Don't output the parsed version of the input file. .IP "\fB\-offset number\fR" 4 .IX Item "-offset number" Starting offset to begin parsing, default is start of file. .IP "\fB\-length number\fR" 4 .IX Item "-length number" Number of bytes to parse, default is until end of file. .IP "\fB\-i\fR" 4 .IX Item "-i" Indents the output according to the \*(L"depth\*(R" of the structures. .IP "\fB\-oid filename\fR" 4 .IX Item "-oid filename" A file containing additional \s-1OBJECT\s0 IDENTIFIERs (OIDs). The format of this file is described in the \s-1NOTES\s0 section below. .IP "\fB\-dump\fR" 4 .IX Item "-dump" Dump unknown data in hex format. .IP "\fB\-dlimit num\fR" 4 .IX Item "-dlimit num" Like \fB\-dump\fR, but only the first \fBnum\fR bytes are output. .IP "\fB\-strparse offset\fR" 4 .IX Item "-strparse offset" Parse the contents octets of the \s-1ASN.1\s0 object starting at \fBoffset\fR. This option can be used multiple times to \*(L"drill down\*(R" into a nested structure. .IP "\fB\-genstr string\fR, \fB\-genconf file\fR" 4 .IX Item "-genstr string, -genconf file" Generate encoded data based on \fBstring\fR, \fBfile\fR or both using \&\fBASN1_generate_nconf\fR\|(3) format. If \fBfile\fR only is present then the string is obtained from the default section using the name \&\fBasn1\fR. The encoded data is passed through the \s-1ASN1\s0 parser and printed out as though it came from a file, the contents can thus be examined and written to a file using the \fBout\fR option. .IP "\fB\-strictpem\fR" 4 .IX Item "-strictpem" If this option is used then \fB\-inform\fR will be ignored. Without this option any data in a \s-1PEM\s0 format input file will be treated as being base64 encoded and processed whether it has the normal \s-1PEM BEGIN\s0 and \s-1END\s0 markers or not. This option will ignore any data prior to the start of the \s-1BEGIN\s0 marker, or after an \&\s-1END\s0 marker in a \s-1PEM\s0 file. .IP "\fB\-item name\fR" 4 .IX Item "-item name" Attempt to decode and print the data as \fB\s-1ASN1_ITEM\s0 name\fR. This can be used to print out the fields of any supported \s-1ASN.1\s0 structure if the type is known. .SS "Output" .IX Subsection "Output" The output will typically contain lines like this: .PP .Vb 1 \& 0:d=0 hl=4 l= 681 cons: SEQUENCE .Ve .PP \&..... .PP .Vb 10 \& 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 .Ve .PP \&..... .PP This example is part of a self-signed certificate. Each line starts with the offset in decimal. \fBd=XX\fR specifies the current depth. The depth is increased within the scope of any \s-1SET\s0 or \s-1SEQUENCE.\s0 \fBhl=XX\fR gives the header length (tag and length octets) of the current type. \fBl=XX\fR gives the length of the contents octets. .PP The \fB\-i\fR option can be used to make the output more readable. .PP Some knowledge of the \s-1ASN.1\s0 structure is needed to interpret the output. .PP In this example the \s-1BIT STRING\s0 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 \fB\-strparse 229\fR to yield: .PP .Vb 3 \& 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 .Ve .SH "NOTES" .IX Header "NOTES" If an \s-1OID\s0 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 \fB\-oid\fR option allows additional OIDs to be included. Each line consists of three columns, the first column is the \s-1OID\s0 in numerical format and should be followed by white space. The second column is the \*(L"short name\*(R" which is a single word followed by white space. The final column is the rest of the line and is the \&\*(L"long name\*(R". \fBasn1parse\fR displays the long name. Example: .PP \&\f(CW\*(C`1.2.3.4 shortName A long name\*(C'\fR .SH "EXAMPLES" .IX Header "EXAMPLES" Parse a file: .PP .Vb 1 \& openssl asn1parse \-in file.pem .Ve .PP Parse a \s-1DER\s0 file: .PP .Vb 1 \& openssl asn1parse \-inform DER \-in file.der .Ve .PP Generate a simple UTF8String: .PP .Vb 1 \& openssl asn1parse \-genstr \*(AqUTF8:Hello World\*(Aq .Ve .PP Generate and write out a UTF8String, don't print parsed output: .PP .Vb 1 \& openssl asn1parse \-genstr \*(AqUTF8:Hello World\*(Aq \-noout \-out utf8.der .Ve .PP Generate using a config file: .PP .Vb 1 \& openssl asn1parse \-genconf asn1.cnf \-noout \-out asn1.der .Ve .PP Example config file: .PP .Vb 1 \& asn1=SEQUENCE:seq_sect \& \& [seq_sect] \& \& field1=BOOL:TRUE \& field2=EXP:0, UTF8:some random string .Ve .SH "BUGS" .IX Header "BUGS" There should be options to change the format of output lines. The output of some \&\s-1ASN.1\s0 types is not well handled (if at all). .SH "SEE ALSO" .IX Header "SEE ALSO" \&\fBASN1_generate_nconf\fR\|(3) .SH "COPYRIGHT" .IX Header "COPYRIGHT" Copyright 2000\-2017 The OpenSSL Project Authors. All Rights Reserved. .PP Licensed under the OpenSSL license (the \*(L"License\*(R"). You may not use this file except in compliance with the License. You can obtain a copy in the file \s-1LICENSE\s0 in the source distribution or at <https://www.openssl.org/source/license.html>.