OCSP 1 2008-05-09 0.9.9-dev OpenSSL
NAME
ocsp - Online Certificate Status Protocol utility
LIBRARY
libcrypto, -lcrypto
SYNOPSIS
ooppeennssssll ooccsspp
[--oouutt ffiillee]
[--iissssuueerr ffiillee]
[--cceerrtt ffiillee]
[--sseerriiaall nn]
[--ssiiggnneerr ffiillee]
[--ssiiggnnkkeeyy ffiillee]
[--ssiiggnn__ootthheerr ffiillee]
[--nnoo__cceerrttss]
[--rreeqq__tteexxtt]
[--rreesspp__tteexxtt]
[--tteexxtt]
[--rreeqqoouutt ffiillee]
[--rreessppoouutt ffiillee]
[--rreeqqiinn ffiillee]
[--rreessppiinn ffiillee]
[--nnoonnccee]
[--nnoo__nnoonnccee]
[--uurrll UURRLL]
[--hhoosstt hhoosstt::nn]
[--ppaatthh]
[--CCAAppaatthh ddiirr]
[--CCAAffiillee ffiillee]
[--VVAAffiillee ffiillee]
[--vvaalliiddiittyy__ppeerriioodd nn]
[--ssttaattuuss__aaggee nn]
[--nnoovveerriiffyy]
[--vveerriiffyy__ootthheerr ffiillee]
[--ttrruusstt__ootthheerr]
[--nnoo__iinntteerrnn]
[--nnoo__ssiiggnnaattuurree__vveerriiffyy]
[--nnoo__cceerrtt__vveerriiffyy]
[--nnoo__cchhaaiinn]
[--nnoo__cceerrtt__cchheecckkss]
[--ppoorrtt nnuumm]
[--iinnddeexx ffiillee]
[--CCAA ffiillee]
[--rrssiiggnneerr ffiillee]
[--rrkkeeyy ffiillee]
[--rrootthheerr ffiillee]
[--rreesspp__nnoo__cceerrttss]
[--nnmmiinn nn]
[--nnddaayyss nn]
[--rreesspp__kkeeyy__iidd]
[--nnrreeqquueesstt nn]
[--mmdd55||--sshhaa11||......]
DESCRIPTION
The Online Certificate Status Protocol (OCSP) enables applications to
determine the (revocation) state of an identified certificate (RFC 2560).
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.
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 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
As noted, most of the verify options are for testing or debugging purposes.
Normally only the --CCAAppaatthh, --CCAAffiillee and (if the responder is a 'global
VA') --VVAAffiillee 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 ooccsspp application in responder mode via a CGI
script using the rreessppiinn and rreessppoouutt 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 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