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dumpasn1 - ASN.1 object dump/syntax check program

DUMPASN1(1) User Commands DUMPASN1(1)


dumpasn1 - ASN.1 object dump/syntax check program


dumpasn1 [ -acdefghilmoprstuvwxz] <file>


An ASN.1 object dump program which will dump data encoded using any of the ASN.1 encoding rules in a variety of user-specified formats.
DumpASN1 - ASN.1 object dump/syntax check program. Copyright Peter Gutmann 1997 - 2012. Last updated 8 August 2015.
Input options:
- = Take input from stdin (some options may not work properly) -<number> = Start <number> bytes into the file -- = End of arg list -c<file> = Read Object Identifier info from alternate config file
(values will override equivalents in global config file)
Output options:
-f<file> = Dump object at offset -<number> to file (allows data to be
extracted from encapsulating objects)
-w<number> = Set 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 ASN.1 structure outline only (no primitive objects)
-h = Hex dump object header (tag+length) before the decoded output
-hh = Same as -h but display more of the object as hex data
-i = Use shallow indenting, for deeply-nested objects
-l = Long format, display extra info about Object Identifiers
= Maximum nesting level for which to display content
-p = Pure ASN.1 output without encoding information
-t = Display text values next to 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 validity of character strings hidden in octet strings
-s = Syntax check only, don't dump ASN.1 structures
-z = Allow zero-length items
Warnings generated by deprecated OIDs require the use of '-l' to be displayed. Program return code is the number of errors found or EXIT_SUCCESS.


This manual page was written by Mathieu Malaterre <> for the Debian GNU/Linux system, but may be used by others.


$HOME/.dumpasn1.cfg, /etc/dumpasn1/dumpasn1.cfg:
This is the configuration file, it will be searched in this order. It contains OIDs commonly used.


quote from Peter Gutmann:
ASN.1 object dumping code, copyright Peter Gutmann <>, based on ASN.1 dump program by David Kemp <>, with contributions from various people including Matthew Hamrick <>, Bruno Couillard <>, Hallvard Furuseth <>, Geoff Thorpe <>, David Boyce <>, John Hughes <>, Life is hard, and then you die <>, Hans-Olof Hermansson <>, Tor Rustad <>, Kjetil Barvik <>, James Sweeny <>, and several other people whose names I've misplaced.
dumpasn1 is available at Copyright Peter Gutmann 1997 - 2012. Last updated 8 August 2015.
October 2016 dumpasn1 20150808