6 ocsp - Online Certificate Status Protocol utility
30 [B<-header name value>]
36 [B<-validity_period n>]
39 [B<-verify_other file>]
42 [B<-no_signature_verify>]
62 The Online Certificate Status Protocol (OCSP) enables applications to
63 determine the (revocation) state of an identified certificate (RFC 2560).
65 The B<ocsp> command performs many common OCSP tasks. It can be used
66 to print out requests and responses, create requests and send queries
67 to an OCSP responder and behave like a mini OCSP server itself.
69 =head1 OCSP CLIENT OPTIONS
73 =item B<-out filename>
75 specify output filename, default is standard output.
77 =item B<-issuer filename>
79 This specifies the current issuer certificate. This option can be used
80 multiple times. The certificate specified in B<filename> must be in
81 PEM format. This option B<MUST> come before any B<-cert> options.
83 =item B<-cert filename>
85 Add the certificate B<filename> to the request. The issuer certificate
86 is taken from the previous B<issuer> option, or an error occurs if no
87 issuer certificate is specified.
91 Same as the B<cert> option except the certificate with serial number
92 B<num> is added to the request. The serial number is interpreted as a
93 decimal integer unless preceded by B<0x>. Negative integers can also
94 be specified by preceding the value by a B<-> sign.
96 =item B<-signer filename>, B<-signkey filename>
98 Sign the OCSP request using the certificate specified in the B<signer>
99 option and the private key specified by the B<signkey> option. If
100 the B<signkey> option is not present then the private key is read
101 from the same file as the certificate. If neither option is specified then
102 the OCSP request is not signed.
104 =item B<-sign_other filename>
106 Additional certificates to include in the signed request.
108 =item B<-nonce>, B<-no_nonce>
110 Add an OCSP nonce extension to a request or disable OCSP nonce addition.
111 Normally if an OCSP request is input using the B<respin> option no
112 nonce is added: using the B<nonce> option will force addition of a nonce.
113 If an OCSP request is being created (using B<cert> and B<serial> options)
114 a nonce is automatically added specifying B<no_nonce> overrides this.
116 =item B<-req_text>, B<-resp_text>, B<-text>
118 print out the text form of the OCSP request, response or both respectively.
120 =item B<-reqout file>, B<-respout file>
122 write out the DER encoded certificate request or response to B<file>.
124 =item B<-reqin file>, B<-respin file>
126 read OCSP request or response file from B<file>. These option are ignored
127 if OCSP request or response creation is implied by other options (for example
128 with B<serial>, B<cert> and B<host> options).
130 =item B<-url responder_url>
132 specify the responder URL. Both HTTP and HTTPS (SSL/TLS) URLs can be specified.
134 =item B<-host hostname:port>, B<-path pathname>
136 if the B<host> option is present then the OCSP request is sent to the host
137 B<hostname> on port B<port>. B<path> specifies the HTTP path name to use
140 =item B<-header name value>
142 If sending a request to an OCSP server, then the specified header name and
143 value are added to the HTTP request. Note that the B<name> and B<value> must
144 be specified as two separate parameters, not as a single quoted string, and
145 that the header name does not have the trailing colon.
146 Some OCSP responders require a Host header; use this flag to provide it.
148 =item B<-timeout seconds>
150 connection timeout to the OCSP responder in seconds
152 =item B<-CAfile file>, B<-CApath pathname>
154 file or pathname containing trusted CA certificates. These are used to verify
155 the signature on the OCSP response.
157 =item B<-no_alt_chains>
159 See L<B<verify>|verify(1)> manual page for details.
161 =item B<-verify_other file>
163 file containing additional certificates to search when attempting to locate
164 the OCSP response signing certificate. Some responders omit the actual signer's
165 certificate from the response: this option can be used to supply the necessary
166 certificate in such cases.
168 =item B<-trust_other>
170 the certificates specified by the B<-verify_other> option should be explicitly
171 trusted and no additional checks will be performed on them. This is useful
172 when the complete responder certificate chain is not available or trusting a
173 root CA is not appropriate.
175 =item B<-VAfile file>
177 file containing explicitly trusted responder certificates. Equivalent to the
178 B<-verify_other> and B<-trust_other> options.
182 don't attempt to verify the OCSP response signature or the nonce values. This
183 option will normally only be used for debugging since it disables all verification
184 of the responders certificate.
188 ignore certificates contained in the OCSP response when searching for the
189 signers certificate. With this option the signers certificate must be specified
190 with either the B<-verify_other> or B<-VAfile> options.
192 =item B<-no_signature_verify>
194 don't check the signature on the OCSP response. Since this option tolerates invalid
195 signatures on OCSP responses it will normally only be used for testing purposes.
197 =item B<-no_cert_verify>
199 don't verify the OCSP response signers certificate at all. Since this option allows
200 the OCSP response to be signed by any certificate it should only be used for
205 do not use certificates in the response as additional untrusted CA
208 =item B<-no_explicit>
210 do not explicitly trust the root CA if it is set to be trusted for OCSP signing.
212 =item B<-no_cert_checks>
214 don't perform any additional checks on the OCSP response signers certificate.
215 That is do not make any checks to see if the signers certificate is authorised
216 to provide the necessary status information: as a result this option should
217 only be used for testing purposes.
219 =item B<-validity_period nsec>, B<-status_age age>
221 these options specify the range of times, in seconds, which will be tolerated
222 in an OCSP response. Each certificate status response includes a B<notBefore> time and
223 an optional B<notAfter> time. The current time should fall between these two values, but
224 the interval between the two times may be only a few seconds. In practice the OCSP
225 responder and clients clocks may not be precisely synchronised and so such a check
226 may fail. To avoid this the B<-validity_period> option can be used to specify an
227 acceptable error range in seconds, the default value is 5 minutes.
229 If the B<notAfter> time is omitted from a response then this means that new status
230 information is immediately available. In this case the age of the B<notBefore> field
231 is checked to see it is not older than B<age> seconds old. By default this additional
232 check is not performed.
234 =item B<-md5|-sha1|-sha256|-ripemod160|...>
236 this option sets digest algorithm to use for certificate identification
237 in the OCSP request. By default SHA-1 is used.
241 =head1 OCSP SERVER OPTIONS
245 =item B<-index indexfile>
247 B<indexfile> is a text index file in B<ca> format containing certificate revocation
250 If the B<index> option is specified the B<ocsp> utility is in responder mode, otherwise
251 it is in client mode. The request(s) the responder processes can be either specified on
252 the command line (using B<issuer> and B<serial> options), supplied in a file (using the
253 B<respin> option) or via external OCSP clients (if B<port> or B<url> is specified).
255 If the B<index> option is present then the B<CA> and B<rsigner> options must also be
260 CA certificate corresponding to the revocation information in B<indexfile>.
262 =item B<-rsigner file>
264 The certificate to sign OCSP responses with.
266 =item B<-rother file>
268 Additional certificates to include in the OCSP response.
270 =item B<-resp_no_certs>
272 Don't include any certificates in the OCSP response.
274 =item B<-resp_key_id>
276 Identify the signer certificate using the key ID, default is to use the subject name.
280 The private key to sign OCSP responses with: if not present the file specified in the
281 B<rsigner> option is used.
283 =item B<-port portnum>
285 Port to listen for OCSP requests on. The port may also be specified using the B<url>
288 =item B<-nrequest number>
290 The OCSP server will exit after receiving B<number> requests, default unlimited.
292 =item B<-nmin minutes>, B<-ndays days>
294 Number of minutes or days when fresh revocation information is available: used in the
295 B<nextUpdate> field. If neither option is present then the B<nextUpdate> field is
296 omitted meaning fresh revocation information is immediately available.
300 =head1 OCSP Response verification.
302 OCSP Response follows the rules specified in RFC2560.
304 Initially the OCSP responder certificate is located and the signature on
305 the OCSP request checked using the responder certificate's public key.
307 Then a normal certificate verify is performed on the OCSP responder certificate
308 building up a certificate chain in the process. The locations of the trusted
309 certificates used to build the chain can be specified by the B<CAfile>
310 and B<CApath> options or they will be looked for in the standard OpenSSL
311 certificates directory.
313 If the initial verify fails then the OCSP verify process halts with an
316 Otherwise the issuing CA certificate in the request is compared to the OCSP
317 responder certificate: if there is a match then the OCSP verify succeeds.
319 Otherwise the OCSP responder certificate's CA is checked against the issuing
320 CA certificate in the request. If there is a match and the OCSPSigning
321 extended key usage is present in the OCSP responder certificate then the
322 OCSP verify succeeds.
324 Otherwise, if B<-no_explicit> is B<not> set the root CA of the OCSP responders
325 CA is checked to see if it is trusted for OCSP signing. If it is the OCSP
328 If none of these checks is successful then the OCSP verify fails.
330 What this effectively means if that if the OCSP responder certificate is
331 authorised directly by the CA it is issuing revocation information about
332 (and it is correctly configured) then verification will succeed.
334 If the OCSP responder is a "global responder" which can give details about
335 multiple CAs and has its own separate certificate chain then its root
336 CA can be trusted for OCSP signing. For example:
338 openssl x509 -in ocspCA.pem -addtrust OCSPSigning -out trustedCA.pem
340 Alternatively the responder certificate itself can be explicitly trusted
341 with the B<-VAfile> option.
345 As noted, most of the verify options are for testing or debugging purposes.
346 Normally only the B<-CApath>, B<-CAfile> and (if the responder is a 'global
347 VA') B<-VAfile> options need to be used.
349 The OCSP server is only useful for test and demonstration purposes: it is
350 not really usable as a full OCSP responder. It contains only a very
351 simple HTTP request handling and can only handle the POST form of OCSP
352 queries. It also handles requests serially meaning it cannot respond to
353 new requests until it has processed the current one. The text index file
354 format of revocation is also inefficient for large quantities of revocation
357 It is possible to run the B<ocsp> application in responder mode via a CGI
358 script using the B<respin> and B<respout> options.
362 Create an OCSP request and write it to a file:
364 openssl ocsp -issuer issuer.pem -cert c1.pem -cert c2.pem -reqout req.der
366 Send a query to an OCSP responder with URL http://ocsp.myhost.com/ save the
367 response to a file and print it out in text form
369 openssl ocsp -issuer issuer.pem -cert c1.pem -cert c2.pem \
370 -url http://ocsp.myhost.com/ -resp_text -respout resp.der
372 Read in an OCSP response and print out text form:
374 openssl ocsp -respin resp.der -text
376 OCSP server on port 8888 using a standard B<ca> configuration, and a separate
377 responder certificate. All requests and responses are printed to a file.
379 openssl ocsp -index demoCA/index.txt -port 8888 -rsigner rcert.pem -CA demoCA/cacert.pem
382 As above but exit after processing one request:
384 openssl ocsp -index demoCA/index.txt -port 8888 -rsigner rcert.pem -CA demoCA/cacert.pem
387 Query status information using internally generated request:
389 openssl ocsp -index demoCA/index.txt -rsigner rcert.pem -CA demoCA/cacert.pem
390 -issuer demoCA/cacert.pem -serial 1
392 Query status information using request read from a file, write response to a
395 openssl ocsp -index demoCA/index.txt -rsigner rcert.pem -CA demoCA/cacert.pem
396 -reqin req.der -respout resp.der
400 The -no_alt_chains options was first added to OpenSSL 1.0.2b.