ocsptool(1)                     User Commands                    ocsptool(1)

NAME         top

       ocsptool - GnuTLS OCSP tool

SYNOPSIS         top

       ocsptool [-flags] [-flag [value]] [--option-name[[=| ]value]]

       All arguments must be options.

DESCRIPTION         top

       Ocsptool is a program that can parse and print information about OCSP
       requests/responses, generate requests and verify responses.

OPTIONS         top

       -d number, --debug=number
              Enable debugging.  This option takes an integer number as its
              argument.  The value of number is constrained to being:
                  in the range  0 through 9999

              Specifies the debug level.

       -V, --verbose
              More verbose output.  This option may appear an unlimited
              number of times.

              Input file.

              Output file.

       --ask [=server name|url]
              Ask an OCSP/HTTP server on a certificate validity.  This
              option must appear in combination with the following options:
              load-cert, load-issuer.

              Connects to the specified HTTP OCSP server and queries on the
              validity of the loaded certificate.

       -e, --verify-response
              Verify response.

       -i, --request-info
              Print information on a OCSP request.

       -j, --response-info
              Print information on a OCSP response.

       -q, --generate-request
              Generate an OCSP request.

       --nonce, --no-nonce
              Use (or not) a nonce to OCSP request.  The no-nonce form will
              disable the option.

              Read issuer certificate from file.

              Read certificate to check from file.

              Read OCSP trust anchors from file.  This option must not
              appear in combination with any of the following options: load-

              Read OCSP response signer from file.  This option must not
              appear in combination with any of the following options: load-

       --inder, --no-inder
              Use DER format for input certificates and private keys.  The
              no-inder form will disable the option.

       -Q file, --load-request=file
              Read DER encoded OCSP request from file.

       -S file, --load-response=file
              Read DER encoded OCSP response from file.

              Ignore any verification errors.

       -h, --help
              Display usage information and exit.

       -!, --more-help
              Pass the extended usage information through a pager.

       -v [{v|c|n --version [{v|c|n}]}]
              Output version of program and exit.  The default mode is `v',
              a simple version.  The `c' mode will print copyright
              information and `n' will print the full copyright notice.

EXAMPLES         top

       Print information about an OCSP request

       To parse an OCSP request and print information about the content, the
       -i or --request-info parameter may be used as follows.  The -Q
       parameter specify the name of the file containing the OCSP request,
       and it should contain the OCSP request in binary DER format.

           $ ocsptool -i -Q ocsp-request.der

       The input file may also be sent to standard input like this:

           $ cat ocsp-request.der | ocsptool --request-info

       Print information about an OCSP response

       Similar to parsing OCSP requests, OCSP responses can be parsed using
       the -j or --response-info as follows.

           $ ocsptool -j -Q ocsp-response.der
           $ cat ocsp-response.der | ocsptool --response-info

       Generate an OCSP request

       The -q or --generate-request parameters are used to generate an OCSP
       request.  By default the OCSP request is written to standard output
       in binary DER format, but can be stored in a file using --outfile.
       To generate an OCSP request the issuer of the certificate to check
       needs to be specified with --load-issuer and the certificate to check
       with --load-cert.  By default PEM format is used for these files,
       although --inder can be used to specify that the input files are in
       DER format.

           $ ocsptool -q --load-issuer issuer.pem --load-cert client.pem            --outfile ocsp-request.der

       When generating OCSP requests, the tool will add an OCSP extension
       containing a nonce.  This behaviour can be disabled by specifying

       Verify signature in OCSP response

       To verify the signature in an OCSP response the -e or
       --verify-response parameter is used.  The tool will read an OCSP
       response in DER format from standard input, or from the file
       specified by --load-response.  The OCSP response is verified against
       a set of trust anchors, which are specified using --load-trust.  The
       trust anchors are concatenated certificates in PEM format.  The
       certificate that signed the OCSP response needs to be in the set of
       trust anchors, or the issuer of the signer certificate needs to be in
       the set of trust anchors and the OCSP Extended Key Usage bit has to
       be asserted in the signer certificate.

           $ ocsptool -e --load-trust issuer.pem            --load-response ocsp-response.der

       The tool will print status of verification.

       Verify signature in OCSP response against given certificate

       It is possible to override the normal trust logic if you know that a
       certain certificate is supposed to have signed the OCSP response, and
       you want to use it to check the signature.  This is achieved using
       --load-signer instead of --load-trust.  This will load one
       certificate and it will be used to verify the signature in the OCSP
       response.  It will not check the Extended Key Usage bit.

           $ ocsptool -e --load-signer ocsp-signer.pem            --load-response ocsp-response.der

       This approach is normally only relevant in two situations.  The first
       is when the OCSP response does not contain a copy of the signer
       certificate, so the --load-trust code would fail.  The second is if
       you want to avoid the indirect mode where the OCSP response signer
       certificate is signed by a trust anchor.

       Real-world example

       Here is an example of how to generate an OCSP request for a
       certificate and to verify the response.  For illustration we'll use
       the host, which (as of writing) uses a certificate
       from CACert.  First we'll use gnutls-cli to get a copy of the server
       certificate chain.  The server is not required to send this
       information, but this particular one is configured to do so.

           $ echo | gnutls-cli -p 443 --print-cert > chain.pem

       Use a text editor on chain.pem to create three files for each
       separate certificates, called cert.pem for the first certificate for
       the domain itself, secondly issuer.pem for the intermediate
       certificate and root.pem for the final root certificate.

       The domain certificate normally contains a pointer to where the OCSP
       responder is located, in the Authority Information Access Information
       extension.  For example, from certtool -i < cert.pem there is this

           Authority Information Access Information (not critical):
           Access Method: (id-ad-ocsp)
           Access Location URI:

       This means the CA support OCSP queries over HTTP.  We are now ready
       to create a OCSP request for the certificate.

           $ ocsptool --ask --load-issuer issuer.pem            --load-cert cert.pem --outfile ocsp-response.der

       The request is sent via HTTP to the OCSP server address specified. If
       the address is omitted ocsptool will use the address stored in the

EXIT STATUS         top

       One of the following exit values will be returned:

       0  (EXIT_SUCCESS)
              Successful program execution.

       1  (EXIT_FAILURE)
              The operation failed or the command syntax was not valid.

       70  (EX_SOFTWARE)
              libopts had an internal operational error.  Please report it
              to  Thank you.

SEE ALSO         top

           certtool (1)

AUTHORS         top

       Nikos Mavrogiannopoulos, Simon Josefsson and others; see
       /usr/share/doc/gnutls/AUTHORS for a complete list.

COPYRIGHT         top

       Copyright (C) 2000-2017 Free Software Foundation, and others all
       rights reserved.  This program is released under the terms of the GNU
       General Public License, version 3 or later.

BUGS         top

       Please send bug reports to:

NOTES         top

       This manual page was AutoGen-erated from the ocsptool option

COLOPHON         top

       This page is part of the GnuTLS (GnuTLS Transport Layer Security
       Library) project.  Information about the project can be found at 
       ⟨⟩.  If you have a bug report for this manual
       page, send it to  This page was obtained from the
       tarball gnutls-3.5.9.tar.xz fetched from 
       ⟨⟩ on 2017-07-05.  If you discover
       any rendering problems in this HTML version of the page, or you
       believe there is a better or more up-to-date source for the page, or
       you have corrections or improvements to the information in this
       COLOPHON (which is not part of the original manual page), send a mail

3.5.9                            12 Feb 2017                     ocsptool(1)