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 key.
COMMAND OPTIONS
-in filename
This specifies the input filename to read from or standard input if this
option is not specified. Ignored if the -key option is used.
-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 PASSPHRASEARGUMENTS section in openssl(1).
-challenge string
specifies the challenge string if an SPKAC is being created.
-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.
-noout
don't output the text version of the SPKAC (not used if an
SPKAC is being created).
-pubkey
output the public key of an SPKAC (not used if an SPKAC is
being created).
-verify
verifies the digital signature on the supplied SPKAC.
EXAMPLES
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":
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
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 attack''.
