# ocsptool

## NAME



           **ocsptool** - GnuTLS OCSP tool
    


## SYNOPSIS



           **ocsptool**[**-flags**] [**-flag**[_value_]] [**--option-name**[[=| ]_value_]]
    
           All arguments must be options.
    


## DESCRIPTION



           **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



           **-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



                  **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



           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.
    


## BUGS



           Please send bug reports to: bugs@gnutls.org
    


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