ocsptool(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXAMPLES | EXIT STATUS | SEE ALSO | AUTHORS | COPYRIGHT | BUGS | COLOPHON

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
       trusted.

OPTIONS         top

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

       Specifies the debug level.

       -V, --verbose More verbose output.

       --infile=file Input file.

       --outfile=str 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 response.

       -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.

       --load-chain=file Reads a set of certificates forming a chain
       from file.

       --load-issuer=file Reads issuer's certificate from file.

       --load-cert=file Reads the certificate to check from file.

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

       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.

       --load-signer=file 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.

       --outder Use DER format for output of responses (this is the
       default).

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

       --outpem 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-errors Ignore any verification errors.

       --verify-allow-broken Allow broken algorithms, such as MD5 for
       verification.

       This can be combined with --verify-response.

       --attime=timestamp Perform validation at the timestamp instead of
       the system time.

       timestamp is an instance in time encoded as Unix time or in a
       human
        readable timestring such as "29 Feb 2004", "2004-02-29".  Full
       documentation available at
       <https://www.gnu.org/software/coreutils/manual/html_node/Date-input-formats.html>
       or locally via info '(coreutils) date invocation'.

       -v arg, --version=arg 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.

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

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

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 --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
              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 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: 1.3.6.1.5.5.7.48.1 (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.

SEE ALSO         top

              certtool(1)

AUTHORS         top


COPYRIGHT         top

       Copyright (C) 2020-2023 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: [email protected]

COLOPHON         top

       This page is part of the GnuTLS (GnuTLS Transport Layer Security
       Library) project.  Information about the project can be found at
       ⟨http:https://www.gnutls.org/⟩.  If you have a bug report for this
       manual page, send it to [email protected].  This page was obtained
       from the tarball gnutls-3.8.2.tar.xz fetched from
       ⟨http:https://www.gnutls.org/download.html⟩ on 2023-12-22.  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 [email protected]

3.8.2                          15 Nov 2023                   ocsptool(1)