NAME

LIBRARY

SYNOPSIS

DESCRIPTION

The ooccsspp 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.

OCSP CLIENT OPTIONS

--oouutt ffiilleennaammee specify output filename, default is standard output.

--iissssuueerr ffiilleennaammee This specifies the current issuer certificate. This option can be used

multiple times. The certificate specified in ffiilleennaammee must be in PEM format. This option MMUUSSTT come before any --cceerrtt options.

--cceerrtt ffiilleennaammee Add the certificate ffiilleennaammee to the request. The issuer certificate

is taken from the previous iissssuueerr option, or an error occurs if no issuer certificate is specified.

--sseerriiaall nnuumm Same as the cceerrtt option except the certificate with serial number

nnuumm is added to the request. The serial number is interpreted as a decimal integer unless preceded by 00xx. Negative integers can also be specified by preceding the value by a -- sign.

--ssiiggnneerr ffiilleennaammee, --ssiiggnnkkeeyy ffiilleennaammee Sign the OCSP request using the certificate specified in the ssiiggnneerr

option and the private key specified by the ssiiggnnkkeeyy option. If the ssiiggnnkkeeyy 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.

--ssiiggnn__ootthheerr ffiilleennaammee Additional certificates to include in the signed request.

--nnoonnccee, --nnoo__nnoonnccee Add an OCSP nonce extension to a request or disable OCSP nonce addition.

Normally if an OCSP request is input using the rreessppiinn option no nonce is added: using the nnoonnccee option will force addition of a nonce. If an OCSP request is being created (using cceerrtt and sseerriiaall options) a nonce is automatically added specifying nnoo__nnoonnccee overrides this.

--rreeqq__tteexxtt, --rreesspp__tteexxtt, --tteexxtt print out the text form of the OCSP request, response or both respectively.

--rreeqqoouutt ffiillee, --rreessppoouutt ffiillee write out the DER encoded certificate request or response to ffiillee.

--rreeqqiinn ffiillee, --rreessppiinn ffiillee read OCSP request or response file from ffiillee. These option are ignored

if OCSP request or response creation is implied by other options (for example with sseerriiaall, cceerrtt and hhoosstt options).

--uurrll rreessppoonnddeerr__uurrll specify the responder URL. Both HTTP and HTTPS (SSL/TLS) URLs can be specified.

--hhoosstt hhoossttnnaammee::ppoorrtt, --ppaatthh ppaatthhnnaammee if the hhoosstt option is present then the OCSP request is sent to the host

hhoossttnnaammee on port ppoorrtt. ppaatthh specifies the HTTP path name to use or "/" by default.

--CCAAffiillee ffiillee, --CCAAppaatthh ppaatthhnnaammee file or pathname containing trusted CA certificates. These are used to verify

the signature on the OCSP response.

--vveerriiffyy__ootthheerr ffiillee 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.

--ttrruusstt__ootthheerr the certificates specified by the --vveerriiffyy__ootthheerr 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.

--VVAAffiillee ffiillee file containing explicitly trusted responder certificates. Equivalent to the

--vveerriiffyy__ootthheerr and --ttrruusstt__ootthheerr options.

--nnoovveerriiffyy 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.

--nnoo__iinntteerrnn 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 --vveerriiffyy__ootthheerr or --VVAAffiillee options.

--nnoo__ssiiggnnaattuurree__vveerriiffyy 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.

--nnoo__cceerrtt__vveerriiffyy 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.

--nnoo__cchhaaiinn do not use certificates in the response as additional untrusted CA

certificates.

--nnoo__cceerrtt__cchheecckkss 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.

--vvaalliiddiittyy__ppeerriioodd nnsseecc, --ssttaattuuss__aaggee aaggee these options specify the range of times, in seconds, which will be tolerated

in an OCSP response. Each certificate status response includes a nnoottBBeeffoorree time and an optional nnoottAAfftteerr 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 --vvaalliiddiittyy__ppeerriioodd option can be used to specify an acceptable error range in seconds, the default value is 5 minutes.

If the nnoottAAfftteerr time is omitted from a response then this means that new status information is immediately available. In this case the age of the nnoottBBeeffoorree field is checked to see it is not older than aaggee seconds old. By default this additional check is not performed.

--mmdd55||--sshhaa11||--sshhaa225566||--rriippeemmoodd116600||...... this option sets digest algorithm to use for certificate identification

in the OCSP request. By default SHA-1 is used.

OCSP SERVER OPTIONS

--iinnddeexx iinnddeexxffiillee iinnddeexxffiillee is a text index file in ccaa format containing certificate revocation

information.

If the iinnddeexx option is specified the ooccsspp 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 iissssuueerr and sseerriiaall options), supplied in a file (using the rreessppiinn option) or via external OCSP clients (if ppoorrtt or uurrll is specified).

If the iinnddeexx option is present then the CCAA and rrssiiggnneerr options must also be present.

--CCAA ffiillee CA certificate corresponding to the revocation information in iinnddeexxffiillee.

--rrssiiggnneerr ffiillee The certificate to sign OCSP responses with.

--rrootthheerr ffiillee Additional certificates to include in the OCSP response.

--rreesspp__nnoo__cceerrttss Don't include any certificates in the OCSP response.

--rreesspp__kkeeyy__iidd Identify the signer certificate using the key ID, default is to use the subject name.

--rrkkeeyy ffiillee The private key to sign OCSP responses with: if not present the file specified in the

rrssiiggnneerr option is used.

--ppoorrtt ppoorrttnnuumm Port to listen for OCSP requests on. The port may also be specified using the uurrll

option.

--nnrreeqquueesstt nnuummbbeerr The OCSP server will exit after receiving nnuummbbeerr requests, default unlimited.

--nnmmiinn mmiinnuutteess, --nnddaayyss ddaayyss Number of minutes or days when fresh revocation information is available: used in the

nneexxttUUppddaattee field. If neither option is present then the nneexxttUUppddaattee field is omitted meaning fresh revocation information is immediately available.

OCSP Response verification.

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 CCAAffiillee and CCAAppaatthh 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 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 --VVAAffiillee option.

NOTES

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 ooccsspp application in responder mode via a CGI script using the rreessppiinn and rreessppoouutt options.

EXAMPLES

 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 and print it out in text form

 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

OCSP server on port 8888 using a standard ccaa 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 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, write response to a second file.

 openssl ocsp -index demoCA/index.txt -rsigner rcert.pem -CA demoCA/cacert.pem
     -reqin req.der -respout resp.der