OPENSSL-OCSP(1SSL) OpenSSL OPENSSL-OCSP(1SSL)
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>.
3.5.4 2025-09-30 OPENSSL-OCSP(1SSL)
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