openssl-spkac, spkac - SPKAC printing and generating utility
openssl spkac [-help] [-in filename]
[-out filename] [-key keyfile] [-keyform
PEM|DER|ENGINE] [-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 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 is used.
- -out filename
- Specifies the output filename to write to or standard output by
- -key keyfile
- Create an SPKAC file using the private key in keyfile. The
-in, -noout, -spksect and -verify options are
ignored if present.
- Whether the key format is PEM, DER, or an engine-backed key. The default
- The input file password source. For more information about the format of
arg see "Pass Phrase Options" 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
- 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
- Output the public key of an SPKAC (not used if an SPKAC is being
- 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 ca utility.
SPKACs are typically generated by Netscape when a form is
submitted containing the KEYGEN tag as part of the certificate
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".
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Licensed under the OpenSSL license (the "License"). You
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