DUMPASN1(1)

💖 DUMPASN1(1) 💖

okay bestie, sit down, we're doing dumpasn1 — it lives in the User Commands section of the manual, and it's about to become your new hyperfixation. ✨

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🌸 NAME 🌸

dumpasn1 — the ASN.1 object dump / syntax check program. that's it, that's the whole vibe. 💅

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🦋 SYNOPSIS 🦋

dumpasn1 [-acdefghilmoprstuvwxz] <file>

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✨ DESCRIPTION ✨

So basically? This is an ASN.1 object dump program, and what it does is dump data encoded using any of the ASN.1 encoding rules in a whole bunch of user-specified formats. like, you pick the format, it serves the data. no cap. 💖

DumpASN1 — ASN.1 object dump/syntax check program. Copyright Peter Gutmann 1997 - 2021. Last updated 12 February 2021. 🫶

🔥 Input options 🔥

• - — take input from stdin (lowkey, some options may not work properly when you do this 🙈)
• -<number> — start <number> bytes into the file
• -- — end of arg list
• -c<file> — read Object Identifier info from an alternate config file

heads up bestie: values from that alternate config will override the equivalents in the global config file. 👑

💜 Output options 💜

• -f<file> — dump the object at offset -<number> to a file (this is the one that lets you extract data from encapsulating objects 🎀)
• -w<number> — set the width of output, default = 80 columns

🎀 Display options 🎀

• -a — print all data in long data blocks, not just the first 128 bytes
• -d — print dots to show column alignment
• -g — display the ASN.1 structure outline only (no primitive objects)
• -h — hex dump the object header (tag+length) before the decoded output
• -hh — same as -h but displays more of the object as hex data
• -i — use shallow indenting, for deeply-nested objects
• -l — long format, displays extra info about Object Identifiers
• -m<number> — maximum nesting level for which to display content
• -p — pure ASN.1 output without encoding information
• -t — display text values next to the hex dump of data
• -v — verbose mode, equivalent to -ahlt

🌈 Format options 🌈

• -e — don't print encapsulated data inside OCTET/BIT STRINGs
• -r — print bits in BIT STRING as encoded in reverse order
• -u — don't format UTCTime/GeneralizedTime string data
• -x — display size and offset in hex, not decimal

⭐ Checking options ⭐

• -o — don't check the validity of character strings hidden in octet strings
• -s — syntax check only, don't dump ASN.1 structures
• -z — allow zero-length items

⚠️ real talk: warnings generated by deprecated OIDs require the use of -l to be displayed. and the program return code is the number of errors found, or EXIT_SUCCESS. remember it. ✨

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🧚 COMMENT 🧚

This manual page was written by Mathieu Malaterre <malat@debian.org> for the Debian GNU/Linux system, but it may be used by others. sharing is caring fr fr. 💖

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🍓 FILES 🍓

$HOME/.dumpasn1.cfg, /etc/dumpasn1/dumpasn1.cfg:

This is the configuration file, and it will be searched in this order. It contains OIDs commonly used. 🗂️

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👑 AUTHOR 👑

quote from Peter Gutmann:

ASN.1 object dumping code, copyright Peter Gutmann <pgut001@cs.auckland.ac.nz>, based on ASN.1 dump program by David Kemp <dpkemp@missi.ncsc.mil>, with contributions from various people including Matthew Hamrick <hamrick@rsa.com>, Bruno Couillard <bcouillard@chrysalis-its.com>, Hallvard Furuseth <h.b.furuseth@usit.uio.no>, Geoff Thorpe <geoff@raas.co.nz>, David Boyce <d.boyce@isode.com>, John Hughes <john.hughes@entegrity.com>, Life is hard, and then you die <ronald@trustpoint.com>, Hans-Olof Hermansson <hans-olof.hermansson@postnet.se>, Tor Rustad <Tor.Rustad@bbs.no>, Kjetil Barvik <kjetil.barvik@bbs.no>, James Sweeny <jsweeny@us.ibm.com>, and several other people whose names I've misplaced. 😭

dumpasn1 is available at https://www.cs.auckland.ac.nz/~pgut001/ 🦋

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💅 COPYRIGHT 💅

Copyright Peter Gutmann 1997 - 2016. Last updated 22 October 2019.

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and that's the whole page, bestie — dumpasn1 version 20210212, from January 2022, the DUMPASN1(1) manual. go forth and dump some objects, you absolute icon. 💖✨🎀🦋🌸