OPENSSL-SPKAC(1SSL) OpenSSL OPENSSL-SPKAC(1SSL)
NAME
openssl-spkac - SPKAC printing and generating command
SYNOPSIS
openssl spkac [-help] [-in filename] [-out filename] [-digest digest]
[-key filename|uri] [-keyform DER|PEM|P12|ENGINE] [-passin arg]
[-challenge string] [-pubkey] [-spkac spkacname] [-spksect section]
[-noout] [-verify] [-engine id] [-provider name] [-provider-path path]
[-provparam [name:]key=value] [-propquery propq]
DESCRIPTION
This 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.
OPTIONS
-help
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
default.
-digest digest
Use the specified digest to sign a created SPKAC file. The default
digest algorithm is MD5.
-key filename|uri
Create an SPKAC file using the private key specified by filename or
uri. The -in, -noout, -spksect and -verify options are ignored if
present.
-keyform DER|PEM|P12|ENGINE
The key format; unspecified by default. See
openssl-format-options(1) for details.
-passin arg
The input file password source. For more information about the
format of arg see openssl-passphrase-options(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.
-engine id
See "Engine Options" in openssl(1). This option is deprecated.
-provider name
-provider-path path
-provparam [name:]key=value
-propquery propq
See "Provider Options" in openssl(1), provider(7), and property(7).
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":
openssl spkac -key key.pem -challenge hello -out spkac.cnf
Example of an SPKAC, (long lines split up for clarity):
SPKAC=MIG5MGUwXDANBgkqhkiG9w0BAQEFAANLADBIAkEA\
1cCoq2Wa3Ixs47uI7FPVwHVIPDx5yso105Y6zpozam135a\
8R0CpoRvkkigIyXfcCjiVi5oWk+6FfPaD03uPFoQIDAQAB\
FgVoZWxsbzANBgkqhkiG9w0BAQQFAANBAFpQtY/FojdwkJ\
h1bEIYuc2EeM2KHTWPEepWYeawvHD0gQ3DngSC75YCWnnD\
dq+NQ3F+X4deMx9AaEglZtULwV4=
NOTES
A created SPKAC with suitable DN components appended can be fed to
openssl-ca(1).
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".
SEE ALSO
openssl(1), openssl-ca(1)
HISTORY
The -engine option was deprecated in OpenSSL 3.0.
The -digest option was added in OpenSSL 3.0.
COPYRIGHT
Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (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
<https://www.openssl.org/source/license.html>.
3.5.4 2025-09-30 OPENSSL-SPKAC(1SSL)
Generated by dwww version 1.16 on Tue Dec 16 04:06:35 CET 2025.