openssl-asn1parse, asn1parse - ASN.1 parsing tool
openssl asn1parse [-help] [-inform PEM|DER] [-in filename] [-out filename] [-noout] [-offset number] [-length number] [-i] [-oid filename] [-dump] [-dlimit num] [-strparse offset] [-genstr string] [-genconf file] [-strictpem] [-item name]
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 data.
Print out a usage message.
The input format. DER is binary format and PEM (the default) is base64 encoded.
The input file, default is standard input.
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.
Starting offset to begin parsing, default is start of file.
Number of bytes to parse, default is until end of file.
Indents the output according to the "depth" of the structures.
A file containing additional OBJECT IDENTIFIERs (OIDs). The format of this file is described in the NOTES section below.
Dump unknown data in hex format.
Like -dump, but only the first num bytes are output.
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.
Generate encoded data based on string, file or both using ASN1_generate_nconf(3) format. If file only is present then the string is obtained from the default section using the name asn1. The encoded data is passed through the ASN1 parser and printed out as though it came from a file, the contents can thus be examined and written to a file using the out option.