Mac Developer Library Developer


This manual page is for Mac OS X version 10.9

If you are running a different version of Mac OS X, view the documentation locally:

  • In Terminal, using the man(1) command

Reading manual pages

Manual pages are intended as a quick reference for people who already understand a technology.

  • To learn how the manual is organized or to learn about command syntax, read the manual page for manpages(5).

  • For more information about this technology, look for other documentation in the Apple Developer Library.

  • For general information about writing shell scripts, read Shell Scripting Primer.

SPKAC(1)                                           OpenSSL                                          SPKAC(1)

       spkac - SPKAC printing and generating utility

       openssl spkac [-in filename] [-out filename] [-key keyfile] [-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.

       -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 PASS PHRASE
           ARGUMENTS 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

           don't output the text version of the SPKAC (not used if an SPKAC is being created).

           output the public key of an SPKAC (not used if an SPKAC is being created).

           verifies the digital signature on the supplied SPKAC.

       -engine id
           specifying an engine (by it's unique id string) will cause req 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 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".


50                                               2013-03-05                                         SPKAC(1)

Reporting Problems

The way to report a problem with this manual page depends on the type of problem:

Content errors
Report errors in the content of this documentation to the OpenSSL project by sending email to
Bug reports
Report bugs in the functionality of the described tool or API to Apple through Bug Reporter and to the OpenSSL project by sending email to
Formatting problems
Report formatting mistakes in the online version of these pages with the feedback links below.