openssl-ocsp, ocsp - Online Certificate Status Protocol utility
openssl ocsp [-help] [-out file] [-issuer
  file] [-cert file] [-serial n] [-signer file]
  [-signkey file] [-sign_other file] [-no_certs]
  [-req_text] [-resp_text] [-text] [-reqout file]
  [-respout file] [-reqin file] [-respin file]
  [-nonce] [-no_nonce] [-url URL] [-host host:port]
  [-multi process-count] [-header] [-path] [-CApath
  dir] [-CAfile file] [-no-CAfile] [-no-CApath]
  [-attime timestamp] [-check_ss_sig] [-crl_check]
  [-crl_check_all] [-explicit_policy] [-extended_crl]
  [-ignore_critical] [-inhibit_any] [-inhibit_map]
  [-no_check_time] [-partial_chain] [-policy arg]
  [-policy_check] [-policy_print] [-purpose purpose]
  [-suiteB_128] [-suiteB_128_only] [-suiteB_192]
  [-trusted_first] [-no_alt_chains] [-use_deltas]
  [-auth_level num] [-verify_depth num] [-verify_email
  email] [-verify_hostname hostname] [-verify_ip ip]
  [-verify_name name] [-x509_strict] [-VAfile file]
  [-validity_period n] [-status_age n] [-noverify]
  [-verify_other file] [-trust_other] [-no_intern]
  [-no_signature_verify] [-no_cert_verify] [-no_chain]
  [-no_cert_checks] [-no_explicit] [-port num]
  [-ignore_err] [-index file] [-CA file] [-rsigner
  file] [-rkey file] [-rother file] [-rsigopt nm:v]
  [-resp_no_certs] [-nmin n] [-ndays n]
  [-resp_key_id] [-nrequest n]
  [-digest]
The Online Certificate Status Protocol (OCSP) enables applications to determine
  the (revocation) state of an identified certificate (RFC 2560).
The ocsp command performs many common OCSP tasks. It can be
    used to print out requests and responses, create requests and send queries
    to an OCSP responder and behave like a mini OCSP server itself.
This command operates as either a client or a server. The options are described
  below, divided into those two modes.
  - -help
- Print out a usage message.
- -out filename
- specify output filename, default is standard output.
- -issuer filename
- This specifies the current issuer certificate. This option can be used
      multiple times. The certificate specified in filename must be in
      PEM format. This option MUST come before any -cert
    options.
- -cert filename
- Add the certificate filename to the request. The issuer certificate
      is taken from the previous issuer option, or an error occurs if no
      issuer certificate is specified.
- -serial num
- Same as the cert option except the certificate with serial number
      num is added to the request. The serial number is interpreted as a
      decimal integer unless preceded by 0x. Negative integers can also
      be specified by preceding the value by a - sign.
- -signer filename, -signkey filename
- Sign the OCSP request using the certificate specified in the signer
      option and the private key specified by the signkey option. If the
      signkey option is not present then the private key is read from the
      same file as the certificate. If neither option is specified then the OCSP
      request is not signed.
- -sign_other filename
- Additional certificates to include in the signed request.
- -nonce, -no_nonce
- Add an OCSP nonce extension to a request or disable OCSP nonce addition.
      Normally if an OCSP request is input using the reqin option no
      nonce is added: using the nonce option will force addition of a
      nonce. If an OCSP request is being created (using cert and
      serial options) a nonce is automatically added specifying
      no_nonce overrides this.
- -req_text, -resp_text, -text
- Print out the text form of the OCSP request, response or both
      respectively.
- -reqout file, -respout file
- Write out the DER encoded certificate request or response to
    file.
- -reqin file, -respin file
- Read OCSP request or response file from file. These option are
      ignored if OCSP request or response creation is implied by other options
      (for example with serial, cert and host
    options).
- -url responder_url
- Specify the responder URL. Both HTTP and HTTPS (SSL/TLS) URLs can be
      specified.
- -host hostname:port, -path pathname
- If the host option is present then the OCSP request is sent to the
      host hostname on port port. path specifies the HTTP
      pathname to use or "/" by default. This is equivalent to
      specifying -url with scheme http:// and the given hostname, port,
      and pathname.
- -header name=value
- Adds the header name with the specified value to the OCSP
      request that is sent to the responder. This may be repeated.
- -timeout seconds
- Connection timeout to the OCSP responder in seconds. On POSIX systems,
      when running as an OCSP responder, this option also limits the time that
      the responder is willing to wait for the client request. This time is
      measured from the time the responder accepts the connection until the
      complete request is received.
- -multi process-count
- Run the specified number of OCSP responder child processes, with the
      parent process respawning child processes as needed. Child processes will
      detect changes in the CA index file and automatically reload it. When
      running as a responder -timeout option is recommended to limit the
      time each child is willing to wait for the client's OCSP response. This
      option is available on POSIX systems (that support the fork() and
      other required unix system-calls).
- -CAfile file, -CApath pathname
- File or pathname containing trusted CA certificates. These are used to
      verify the signature on the OCSP response.
- -no-CAfile
- Do not load the trusted CA certificates from the default file
    location
- -no-CApath
- Do not load the trusted CA certificates from the default directory
      location
- -attime, -check_ss_sig, -crl_check,
    -crl_check_all, -explicit_policy, -extended_crl,
    -ignore_critical, -inhibit_any, -inhibit_map,
    -no_alt_chains, -no_check_time, -partial_chain,
    -policy, -policy_check, -policy_print, -purpose,
    -suiteB_128, -suiteB_128_only, -suiteB_192,
    -trusted_first, -use_deltas, -auth_level,
    -verify_depth, -verify_email, -verify_hostname,
    -verify_ip, -verify_name, -x509_strict
- Set different certificate verification options. See verify(1)
      manual page for details.
- -verify_other file
- File containing additional certificates to search when attempting to
      locate the OCSP response signing certificate. Some responders omit the
      actual signer's certificate from the response: this option can be used to
      supply the necessary certificate in such cases.
- -trust_other
- The certificates specified by the -verify_other option should be
      explicitly trusted and no additional checks will be performed on them.
      This is useful when the complete responder certificate chain is not
      available or trusting a root CA is not appropriate.
- -VAfile file
- File containing explicitly trusted responder certificates. Equivalent to
      the -verify_other and -trust_other options.
- -noverify
- Don't attempt to verify the OCSP response signature or the nonce values.
      This option will normally only be used for debugging since it disables all
      verification of the responders certificate.
- -no_intern
- Ignore certificates contained in the OCSP response when searching for the
      signers certificate. With this option the signers certificate must be
      specified with either the -verify_other or -VAfile
    options.
- -no_signature_verify
- Don't check the signature on the OCSP response. Since this option
      tolerates invalid signatures on OCSP responses it will normally only be
      used for testing purposes.
- -no_cert_verify
- Don't verify the OCSP response signers certificate at all. Since this
      option allows the OCSP response to be signed by any certificate it should
      only be used for testing purposes.
- -no_chain
- Do not use certificates in the response as additional untrusted CA
      certificates.
- -no_explicit
- Do not explicitly trust the root CA if it is set to be trusted for OCSP
      signing.
- -no_cert_checks
- Don't perform any additional checks on the OCSP response signers
      certificate. That is do not make any checks to see if the signers
      certificate is authorised to provide the necessary status information: as
      a result this option should only be used for testing purposes.
- -validity_period nsec, -status_age age
- These options specify the range of times, in seconds, which will be
      tolerated in an OCSP response. Each certificate status response includes a
      notBefore time and an optional notAfter time. The current
      time should fall between these two values, but the interval between the
      two times may be only a few seconds. In practice the OCSP responder and
      clients clocks may not be precisely synchronised and so such a check may
      fail. To avoid this the -validity_period option can be used to
      specify an acceptable error range in seconds, the default value is 5
      minutes.
    If the notAfter time is omitted from a response then
        this means that new status information is immediately available. In this
        case the age of the notBefore field is checked to see it is not
        older than age seconds old. By default this additional check is
        not performed. 
- -digest
- This option sets digest algorithm to use for certificate identification in
      the OCSP request. Any digest supported by the OpenSSL dgst command
      can be used. The default is SHA-1. This option may be used multiple times
      to specify the digest used by subsequent certificate identifiers.
  - -index indexfile
- The indexfile parameter is the name of a text index file in
      ca format containing certificate revocation information.
    If the index option is specified the ocsp
        utility is in responder mode, otherwise it is in client mode. The
        request(s) the responder processes can be either specified on the
        command line (using issuer and serial options), supplied
        in a file (using the reqin option) or via external OCSP clients
        (if port or url is specified). If the index option is present then the CA and
        rsigner options must also be present. 
- -CA file
- CA certificate corresponding to the revocation information in
      indexfile.
- -rsigner file
- The certificate to sign OCSP responses with.
- -rother file
- Additional certificates to include in the OCSP response.
- -resp_no_certs
- Don't include any certificates in the OCSP response.
- -resp_key_id
- Identify the signer certificate using the key ID, default is to use the
      subject name.
- -rkey file
- The private key to sign OCSP responses with: if not present the file
      specified in the rsigner option is used.
- -rsigopt nm:v
- Pass options to the signature algorithm when signing OCSP responses. Names
      and values of these options are algorithm-specific.
- -port portnum
- Port to listen for OCSP requests on. The port may also be specified using
      the url option.
- -ignore_err
- Ignore malformed requests or responses: When acting as an OCSP client,
      retry if a malformed response is received. When acting as an OCSP
      responder, continue running instead of terminating upon receiving a
      malformed request.
- -nrequest number
- The OCSP server will exit after receiving number requests, default
      unlimited.
- -nmin minutes, -ndays days
- Number of minutes or days when fresh revocation information is available:
      used in the nextUpdate field. If neither option is present then the
      nextUpdate field is omitted meaning fresh revocation information is
      immediately available.
OCSP Response follows the rules specified in RFC2560.Initially the OCSP responder certificate is located and the
    signature on the OCSP request checked using the responder certificate's
    public key.
Then a normal certificate verify is performed on the OCSP
    responder certificate building up a certificate chain in the process. The
    locations of the trusted certificates used to build the chain can be
    specified by the CAfile and CApath options or they will be
    looked for in the standard OpenSSL certificates directory.
If the initial verify fails then the OCSP verify process halts
    with an error.
Otherwise the issuing CA certificate in the request is compared to
    the OCSP responder certificate: if there is a match then the OCSP verify
    succeeds.
Otherwise the OCSP responder certificate's CA is checked against
    the issuing CA certificate in the request. If there is a match and the
    OCSPSigning extended key usage is present in the OCSP responder certificate
    then the OCSP verify succeeds.
Otherwise, if -no_explicit is not set the root CA of
    the OCSP responders CA is checked to see if it is trusted for OCSP signing.
    If it is the OCSP verify succeeds.
If none of these checks is successful then the OCSP verify
  fails.
What this effectively means if that if the OCSP responder
    certificate is authorised directly by the CA it is issuing revocation
    information about (and it is correctly configured) then verification will
    succeed.
If the OCSP responder is a "global responder" which can
    give details about multiple CAs and has its own separate certificate chain
    then its root CA can be trusted for OCSP signing. For example:
 openssl x509 -in ocspCA.pem -addtrust OCSPSigning -out trustedCA.pem
Alternatively the responder certificate itself can be explicitly
    trusted with the -VAfile option.
As noted, most of the verify options are for testing or debugging purposes.
  Normally only the -CApath, -CAfile and (if the responder is a
  'global VA') -VAfile options need to be used.
The OCSP server is only useful for test and demonstration
    purposes: it is not really usable as a full OCSP responder. It contains only
    a very simple HTTP request handling and can only handle the POST form of
    OCSP queries. It also handles requests serially meaning it cannot respond to
    new requests until it has processed the current one. The text index file
    format of revocation is also inefficient for large quantities of revocation
    data.
It is possible to run the ocsp application in responder
    mode via a CGI script using the reqin and respout options.
Create an OCSP request and write it to a file:
 openssl ocsp -issuer issuer.pem -cert c1.pem -cert c2.pem -reqout req.der
Send a query to an OCSP responder with URL http://ocsp.myhost.com/
    save the response to a file, print it out in text form, and verify the
    response:
 openssl ocsp -issuer issuer.pem -cert c1.pem -cert c2.pem \
     -url http://ocsp.myhost.com/ -resp_text -respout resp.der
Read in an OCSP response and print out text form:
 openssl ocsp -respin resp.der -text -noverify
OCSP server on port 8888 using a standard ca configuration,
    and a separate responder certificate. All requests and responses are printed
    to a file.
 openssl ocsp -index demoCA/index.txt -port 8888 -rsigner rcert.pem -CA demoCA/cacert.pem
        -text -out log.txt
As above but exit after processing one request:
 openssl ocsp -index demoCA/index.txt -port 8888 -rsigner rcert.pem -CA demoCA/cacert.pem
     -nrequest 1
Query status information using an internally generated
  request:
 openssl ocsp -index demoCA/index.txt -rsigner rcert.pem -CA demoCA/cacert.pem
     -issuer demoCA/cacert.pem -serial 1
Query status information using request read from a file, and write
    the response to a second file.
 openssl ocsp -index demoCA/index.txt -rsigner rcert.pem -CA demoCA/cacert.pem
     -reqin req.der -respout resp.der
The -no_alt_chains option was added in OpenSSL 1.1.0.
Copyright 2001-2020 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the OpenSSL license (the "License"). You
    may not use this file except in compliance with the License. You can obtain
    a copy in the file LICENSE in the source distribution or at
    <https://www.openssl.org/source/license.html>.