spkac — SPKAC printing and generating utility
openssl spkac [-in filename] [-out filename] [-key keyfile] [-passin arg] [-challenge string] [-pubkey] [-spkac spkacname] [-spksect section] [-noout] [-verify] [-engine id]
The spkac 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
This specifies the input filename to read from or standard
input if this option is not specified. Ignored if the -key option
specifies the output filename to write to or standard output
create an SPKAC file using the private key in keyfile. The
-in, -nout, -spksect and -verify options are ignored if present.
the input file password source. For more information about
the format of arg see the PASS PHRASE ARGUMENTS section in openssl(1).
specifies the challenge string if an SPKAC is being created.
allows an alternative name form the variable containing the
SPKAC. The default is "SPKAC". This option affects both generated
and input SPKAC files.
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.
specifying an engine (by it's unique id string) will cause
req 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 ca utility.
SPKACs are typically generated by Netscape when a form is
submitted containing the KEYGEN tag as part of the certificate enrollment
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 attack".