Provided by: openssl_3.5.0-2ubuntu1_amd64 
NAME
openssl-ocsp - Online Certificate Status Protocol command
SYNOPSIS
OCSP Client
openssl ocsp [-help] [-out file] [-issuer file] [-cert file] [-no_certs] [-serial n] [-signer file]
[-signkey file] [-sign_other file] [-nonce] [-no_nonce] [-req_text] [-resp_text] [-text] [-reqout
filename] [-respout filename] [-reqin filename] [-respin filename] [-url URL] [-host host:port] [-path
pathname] [-proxy [http[s]://][userinfo@]host[:port][/path][?query][#fragment]] [-no_proxy addresses]
[-header] [-timeout seconds] [-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]
OCSP Server
openssl ocsp [-index file] [-CA file] [-rsigner file] [-rkey file] [-passin arg] [-rother file] [-rsigopt
nm:v] [-rmd digest] [-badsig] [-resp_no_certs] [-nmin n] [-ndays n] [-resp_key_id] [-nrequest n] [-multi
process-count] [-rcid digest] [-digest] [-CAfile file] [-no-CAfile] [-CApath dir] [-no-CApath] [-CAstore
uri] [-no-CAstore] [-allow_proxy_certs] [-attime timestamp] [-no_check_time] [-check_ss_sig] [-crl_check]
[-crl_check_all] [-explicit_policy] [-extended_crl] [-ignore_critical] [-inhibit_any] [-inhibit_map]
[-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] [-issuer_checks] [-provider name] [-provider-path path] [-provparam [name:]key=value]
[-propquery propq]
DESCRIPTION
The Online Certificate Status Protocol (OCSP) enables applications to determine the (revocation) state of
an identified certificate (RFC 2560).
This 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.
OPTIONS
This command operates as either a client or a server. The options are described below, divided into
those two modes.
OCSP Client Options
-help
Print out a usage message.
-out filename
specify output filename, default is standard output.
-issuer filename
This specifies the current issuer certificate. The input can be in PEM, DER, or PKCS#12 format.
This option can be used multiple times. This option MUST come before any -cert options.
-cert filename
Add the certificate filename to the request. The input can be in PEM, DER, or PKCS#12 format.
This option can be used multiple times. The issuer certificate is taken from the previous -issuer
option, or an error occurs if no issuer certificate is specified.
-no_certs
Don't include any certificates in signed request.
-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. The input can be in PEM, DER, or PKCS#12 format.
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. The input can be in PEM, DER, or PKCS#12
format.
-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 filename
Write out the DER-encoded OCSP request or response to filename. The output filename can be the same
as the input filename, which leads to replacing the file contents. Note that file I/O is not atomic.
The output file is truncated and then written.
-reqin file, -respin filename
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 host and optionally port and path via a URL. Both HTTP and HTTPS (SSL/TLS)
URLs can be specified. The optional userinfo and fragment components are ignored. Any given query
component is handled as part of the path component. For details, see the -host and -path options
described next.
-host host:port, -path pathname
If the -host option is present then the OCSP request is sent to the host host on port port. The host
may be a domain name or an IP (v4 or v6) address, such as 127.0.0.1 or "[::1]" for localhost. If it
is an IPv6 address, it must be enclosed in "[" and "]".
The -path option specifies the HTTP pathname to use or "/" by default. This is equivalent to
specifying -url with scheme http:// and the given host, port, and optional pathname.
-proxy [http[s]://][userinfo@]host[:port][/path][?query][#fragment]
The HTTP(S) proxy server to use for reaching the OCSP server unless -no_proxy applies, see below. If
the host string is an IPv6 address, it must be enclosed in "[" and "]". The proxy port defaults to
80 or 443 if the scheme is "https"; apart from that the optional "http://" or "https://" prefix is
ignored, as well as any userinfo, path, query, and fragment components. Defaults to the environment
variable "http_proxy" if set, else "HTTP_PROXY" in case no TLS is used, otherwise "https_proxy" if
set, else "HTTPS_PROXY".
-no_proxy addresses
List of IP addresses and/or DNS names of servers not to use an HTTP(S) proxy for, separated by commas
and/or whitespace (where in the latter case the whole argument must be enclosed in "..."). Default
is from the environment variable "no_proxy" if set, else "NO_PROXY".
-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.
-verify_other file
File or URI 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. The input can be in PEM, DER,
or PKCS#12 format.
-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 or URI containing explicitly trusted responder certificates. Equivalent to the -verify_other
and -trust_other options. The input can be in PEM, DER, or PKCS#12 format.
-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.
-rcid digest
This option sets the digest algorithm to use for certificate identification in the OCSP response. Any
digest supported by the openssl-dgst(1) command can be used. The default is the same digest algorithm
used in the request.
-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.
-CAfile file, -no-CAfile, -CApath dir, -no-CApath, -CAstore uri, -no-CAstore
See "Trusted Certificate Options" in openssl-verification-options(1) for details.
-allow_proxy_certs, -attime, -no_check_time, -check_ss_sig, -crl_check, -crl_check_all, -explicit_policy,
-extended_crl, -ignore_critical, -inhibit_any, -inhibit_map, -no_alt_chains, -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 -issuer_checks
Set various options of certificate chain verification. See "Verification Options" in
openssl-verification-options(1) for details.
-provider name
-provider-path path
-provparam [name:]key=value
-propquery propq
See "Provider Options" in openssl(1), provider(7), and property(7).
OCSP Server Options
-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 then this command switches to 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 certificates corresponding to the revocation information in the index file given with -index. The
input can be in PEM, DER, or PKCS#12 format.
-rsigner file
The certificate to sign OCSP responses with. The input can be in PEM, DER, or PKCS#12 format.
-rkey file
The private key to sign OCSP responses with: if not present the file specified in the -rsigner option
is used.
-passin arg
The private key password source. For more information about the format of arg see
openssl-passphrase-options(1).
-rother file
Additional certificates to include in the OCSP response. The input can be in PEM, DER, or PKCS#12
format.
-rsigopt nm:v
Pass options to the signature algorithm when signing OCSP responses. Names and values of these
options are algorithm-specific.
-rmd digest
The digest to use when signing the response.
-badsig
Corrupt the response signature before writing it; this can be useful for testing.
-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.
-port portnum
Port to listen for OCSP requests on. Both IPv4 and IPv6 are possible. The port may also be specified
using the -url option. A 0 argument indicates that any available port shall be chosen automatically.
-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.
-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).
-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 VERIFICATION
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, -CApath or -CAstore 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.
NOTES
As noted, most of the verify options are for testing or debugging purposes. Normally only the -CApath,
-CAfile, -CAstore 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 this command in responder mode via a CGI script using the -reqin and -respout
options.
EXAMPLES
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
HISTORY
The -no_alt_chains option was added in OpenSSL 1.1.0.
COPYRIGHT
Copyright 2001-2023 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (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>.
3.5.0 2025-06-04 OPENSSL-OCSP(1SSL)