OPENSSL-SPKAC(1)

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] [-passin arg] [-challenge string] [-pubkey] [-spkac spkacname] [-spksect section] [-noout] [-verify] [-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
    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.

-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 -digest option was added in OpenSSL 3.0.

The -engine option was removed in OpenSSL 4.0.

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>.