ocsptool(1) — Linux manual page


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

       On verification
       Responses are typically signed/issued by designated certificates
       or certificate authorities and thus this tool requires on
       verification the certificate of the issuer or the full
       certificate chain in order to determine the appropriate signing
       authority. The specified certificate of the issuer is assumed

OPTIONS         top

       -d number, --debug=number
              Enable debugging.  This option takes an integer number as
              its argument.  The value of number is constrained to
                  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.

              Connects to the specified HTTP OCSP server and queries on
              the validity of the loaded certificate.  Its argument can
              be a URL or a plain server name. It can be combined with
              --load-chain, where it checks all certificates in the
              provided chain, or with --load-cert and --load-issuer
              options. The latter checks the provided certificate
              against its specified issuer certificate.

       -e, --verify-response
              Verify response.

              Verifies the provided OCSP response against the system
              trust anchors (unless --load-trust is provided). It
              requires the --load-signer or --load-chain options to
              obtain the signer of the OCSP response.

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

              Display detailed information on the provided OCSP request.

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

              Display detailed information on the provided OCSP

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

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

              Reads a set of certificates forming a chain from file.

              Reads issuer's certificate from file.

              Reads the certificate to check from file.

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

              When verifying an OCSP response read the trust anchors
              from the provided file. When this is not provided, the
              system's trust anchors will be used.

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

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

              Use DER format for output of responses (this is the

              The output will be in DER encoded format. Unlike other
              GnuTLS tools, this is the default for this tool

              Use PEM format for output of responses.

              The output will be in PEM format.

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

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

              Ignore any verification errors.

              Allow broken algorithms, such as MD5 for verification.

              This can be combined with --verify-response.

       -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

           $ 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 --no-nonce.

       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

           $ 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

           $ 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 blog.josefsson.org 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 blog.josefsson.org --save-cert chain.pem

       The saved certificates normally contain a pointer to where the
       OCSP responder is located, in the Authority Information Access
       Information extension.  For example, from certtool -i < chain.pem
       there is this information:

           Authority Information Access Information (not critical):
           Access Method: (id-ad-ocsp)
           Access Location URI: https://ocsp.CAcert.org/

       This means that ocsptool can discover the servers to contact over
       HTTP.  We can now request information on the chain certificates.

           $ ocsptool --ask --load-chain chain.pem

       The request is sent via HTTP to the OCSP server address found in
       the certificates. It is possible to override the address of the
       OCSP server as well as ask information on a particular
       certificate using --load-cert and --load-issuer.

           $ ocsptool --ask https://ocsp.CAcert.org/ --load-chain chain.pem

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 autogen-users@lists.sourceforge.net.  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) 2000-2020 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: bugs@gnutls.org

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
       ⟨http://www.gnutls.org/⟩.  If you have a bug report for this
       manual page, send it to bugs@gnutls.org.  This page was obtained
       from the tarball gnutls-3.7.2.tar.xz fetched from
       ⟨http://www.gnutls.org/download.html⟩ on 2021-08-27.  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 to man-pages@man7.org

3.7.2                          29 May 2021                   ocsptool(1)