openssl-spkac, spkac - SPKAC printing and generating utility
] [ -in filename
] [ -out
] [ -key keyfile
] [ -passin arg
] [ -challenge
] [ -pubkey
] [ -spkac spkacname
] [ -spksect
] [ -noout
] [ -verify
] [ -engine id
command processes Netscape signed public key and challenge
(SPKAC) files. It can print out their contents, verify the signature and
produce its own SPKACs from a supplied private key.
- Print out a usage message.
- -in filename
- This specifies the input filename to read from or standard
input if this option is not specified. Ignored if the -key option
- -out filename
- specifies the output filename to write to or standard
output by default.
- -key keyfile
- create an SPKAC file using the private key in
keyfile. The -in, -noout, -spksect and
-verify options are ignored if present.
- -passin password
- the input file password source. For more information about
the format of arg see the PASS PHRASE ARGUMENTS section in
- -challenge string
- specifies the challenge string if an SPKAC is being
- -spkac spkacname
- allows an alternative name form the variable containing the
SPKAC. The default is "SPKAC". This option affects both
generated and input SPKAC files.
- -spksect section
- allows an alternative name form the section containing the
SPKAC. The default is the default section.
- don't output the text version of the SPKAC (not used if an
SPKAC is being created).
- output the public key of an SPKAC (not used if an SPKAC is
- verifies the digital signature on the supplied SPKAC.
- -engine id
- specifying an engine (by its unique id string) will
cause spkac to attempt to obtain a functional reference to the
specified engine, thus initialising it if needed. The engine will then be
set as the default for all available algorithms.
Print out the contents of an SPKAC:
openssl spkac -in spkac.cnf
Verify the signature of an SPKAC:
openssl spkac -in spkac.cnf -noout -verify
Create an SPKAC using the challenge string "hello":
openssl spkac -key key.pem -challenge hello -out spkac.cnf
Example of an SPKAC, (long lines split up for clarity):
A created SPKAC with suitable DN components appended can be fed into the
SPKACs are typically generated by Netscape when a form is submitted containing
tag as part of the certificate enrollment process.
The challenge string permits a primitive form of proof of possession of private
key. By checking the SPKAC signature and a random challenge string some
guarantee is given that the user knows the private key corresponding to the
public key being certified. This is important in some applications. Without
this it is possible for a previous SPKAC to be used in a "replay
Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the OpenSSL license (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy in the
file LICENSE in the source distribution or at