# openssl-spkac(1ssl) - man - phpman

[OPENSSL-SPKAC(1SSL)](https://www.chedong.com/phpMan.php/man/OPENSSL-SPKAC/1SSL/markdown)                            OpenSSL                           [OPENSSL-SPKAC(1SSL)](https://www.chedong.com/phpMan.php/man/OPENSSL-SPKAC/1SSL/markdown)



## 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_]
       [**-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
           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
           Specifies the output filename to write to or standard output by default.

### -digest
           Use the specified _digest_ to sign a created SPKAC file.  The default digest algorithm is
           MD5.

### -key
           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
           The key format; unspecified by default.  See [**openssl-format-options**(1)](https://www.chedong.com/phpMan.php/man/openssl-format-options/1/markdown) for details.

### -passin
           The input file password source. For more information about the format of _arg_ see
           [**openssl-passphrase-options**(1)](https://www.chedong.com/phpMan.php/man/openssl-passphrase-options/1/markdown).

### -challenge
           Specifies the challenge string if an SPKAC is being created.

### -spkac
           Allows an alternative name form the variable containing the SPKAC. The default is
           "SPKAC". This option affects both generated and input SPKAC files.

### -spksect
           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
           See "Engine Options" in [**openssl**(1)](https://www.chedong.com/phpMan.php/man/openssl/1/markdown).  This option is deprecated.

### -provider
### -provider-path
### -propquery
           See "Provider Options" in [**openssl**(1)](https://www.chedong.com/phpMan.php/man/openssl/1/markdown), [**provider**(7)](https://www.chedong.com/phpMan.php/man/provider/7/markdown), and [**property**(7)](https://www.chedong.com/phpMan.php/man/property/7/markdown).

## 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)](https://www.chedong.com/phpMan.php/man/openssl-ca/1/markdown).

       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)](https://www.chedong.com/phpMan.php/man/openssl/1/markdown), [**openssl-ca**(1)](https://www.chedong.com/phpMan.php/man/openssl-ca/1/markdown)

## 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>>.



3.0.2                                        2026-04-07                          [OPENSSL-SPKAC(1SSL)](https://www.chedong.com/phpMan.php/man/OPENSSL-SPKAC/1SSL/markdown)