1=pod 2 3=head1 NAME 4 5ocsp - Online Certificate Status Protocol utility 6 7=head1 SYNOPSIS 8 9B<openssl> B<ocsp> 10[B<-out file>] 11[B<-issuer file>] 12[B<-cert file>] 13[B<-serial n>] 14[B<-signer file>] 15[B<-signkey file>] 16[B<-sign_other file>] 17[B<-no_certs>] 18[B<-req_text>] 19[B<-resp_text>] 20[B<-text>] 21[B<-reqout file>] 22[B<-respout file>] 23[B<-reqin file>] 24[B<-respin file>] 25[B<-nonce>] 26[B<-no_nonce>] 27[B<-url URL>] 28[B<-host host:n>] 29[B<-path>] 30[B<-CApath dir>] 31[B<-CAfile file>] 32[B<-no_alt_chains>]] 33[B<-VAfile file>] 34[B<-validity_period n>] 35[B<-status_age n>] 36[B<-noverify>] 37[B<-verify_other file>] 38[B<-trust_other>] 39[B<-no_intern>] 40[B<-no_signature_verify>] 41[B<-no_cert_verify>] 42[B<-no_chain>] 43[B<-no_cert_checks>] 44[B<-no_explicit>] 45[B<-port num>] 46[B<-index file>] 47[B<-CA file>] 48[B<-rsigner file>] 49[B<-rkey file>] 50[B<-rother file>] 51[B<-resp_no_certs>] 52[B<-nmin n>] 53[B<-ndays n>] 54[B<-resp_key_id>] 55[B<-nrequest n>] 56[B<-md5|-sha1|...>] 57 58=head1 DESCRIPTION 59 60The Online Certificate Status Protocol (OCSP) enables applications to 61determine the (revocation) state of an identified certificate (RFC 2560). 62 63The B<ocsp> command performs many common OCSP tasks. It can be used 64to print out requests and responses, create requests and send queries 65to an OCSP responder and behave like a mini OCSP server itself. 66 67=head1 OCSP CLIENT OPTIONS 68 69=over 4 70 71=item B<-out filename> 72 73specify output filename, default is standard output. 74 75=item B<-issuer filename> 76 77This specifies the current issuer certificate. This option can be used 78multiple times. The certificate specified in B<filename> must be in 79PEM format. This option B<MUST> come before any B<-cert> options. 80 81=item B<-cert filename> 82 83Add the certificate B<filename> to the request. The issuer certificate 84is taken from the previous B<issuer> option, or an error occurs if no 85issuer certificate is specified. 86 87=item B<-serial num> 88 89Same as the B<cert> option except the certificate with serial number 90B<num> is added to the request. The serial number is interpreted as a 91decimal integer unless preceded by B<0x>. Negative integers can also 92be specified by preceding the value by a B<-> sign. 93 94=item B<-signer filename>, B<-signkey filename> 95 96Sign the OCSP request using the certificate specified in the B<signer> 97option and the private key specified by the B<signkey> option. If 98the B<signkey> option is not present then the private key is read 99from the same file as the certificate. If neither option is specified then 100the OCSP request is not signed. 101 102=item B<-sign_other filename> 103 104Additional certificates to include in the signed request. 105 106=item B<-nonce>, B<-no_nonce> 107 108Add an OCSP nonce extension to a request or disable OCSP nonce addition. 109Normally if an OCSP request is input using the B<respin> option no 110nonce is added: using the B<nonce> option will force addition of a nonce. 111If an OCSP request is being created (using B<cert> and B<serial> options) 112a nonce is automatically added specifying B<no_nonce> overrides this. 113 114=item B<-req_text>, B<-resp_text>, B<-text> 115 116print out the text form of the OCSP request, response or both respectively. 117 118=item B<-reqout file>, B<-respout file> 119 120write out the DER encoded certificate request or response to B<file>. 121 122=item B<-reqin file>, B<-respin file> 123 124read OCSP request or response file from B<file>. These option are ignored 125if OCSP request or response creation is implied by other options (for example 126with B<serial>, B<cert> and B<host> options). 127 128=item B<-url responder_url> 129 130specify the responder URL. Both HTTP and HTTPS (SSL/TLS) URLs can be specified. 131 132=item B<-host hostname:port>, B<-path pathname> 133 134if the B<host> option is present then the OCSP request is sent to the host 135B<hostname> on port B<port>. B<path> specifies the HTTP path name to use 136or "/" by default. 137 138=item B<-timeout seconds> 139 140connection timeout to the OCSP responder in seconds 141 142=item B<-CAfile file>, B<-CApath pathname> 143 144file or pathname containing trusted CA certificates. These are used to verify 145the signature on the OCSP response. 146 147=item B<-no_alt_chains> 148 149See L<B<verify>|verify(1)> manual page for details. 150 151=item B<-verify_other file> 152 153file containing additional certificates to search when attempting to locate 154the OCSP response signing certificate. Some responders omit the actual signer's 155certificate from the response: this option can be used to supply the necessary 156certificate in such cases. 157 158=item B<-trust_other> 159 160the certificates specified by the B<-verify_other> option should be explicitly 161trusted and no additional checks will be performed on them. This is useful 162when the complete responder certificate chain is not available or trusting a 163root CA is not appropriate. 164 165=item B<-VAfile file> 166 167file containing explicitly trusted responder certificates. Equivalent to the 168B<-verify_other> and B<-trust_other> options. 169 170=item B<-noverify> 171 172don't attempt to verify the OCSP response signature or the nonce values. This 173option will normally only be used for debugging since it disables all verification 174of the responders certificate. 175 176=item B<-no_intern> 177 178ignore certificates contained in the OCSP response when searching for the 179signers certificate. With this option the signers certificate must be specified 180with either the B<-verify_other> or B<-VAfile> options. 181 182=item B<-no_signature_verify> 183 184don't check the signature on the OCSP response. Since this option tolerates invalid 185signatures on OCSP responses it will normally only be used for testing purposes. 186 187=item B<-no_cert_verify> 188 189don't verify the OCSP response signers certificate at all. Since this option allows 190the OCSP response to be signed by any certificate it should only be used for 191testing purposes. 192 193=item B<-no_chain> 194 195do not use certificates in the response as additional untrusted CA 196certificates. 197 198=item B<-no_explicit> 199 200do not explicitly trust the root CA if it is set to be trusted for OCSP signing. 201 202=item B<-no_cert_checks> 203 204don't perform any additional checks on the OCSP response signers certificate. 205That is do not make any checks to see if the signers certificate is authorised 206to provide the necessary status information: as a result this option should 207only be used for testing purposes. 208 209=item B<-validity_period nsec>, B<-status_age age> 210 211these options specify the range of times, in seconds, which will be tolerated 212in an OCSP response. Each certificate status response includes a B<notBefore> time and 213an optional B<notAfter> time. The current time should fall between these two values, but 214the interval between the two times may be only a few seconds. In practice the OCSP 215responder and clients clocks may not be precisely synchronised and so such a check 216may fail. To avoid this the B<-validity_period> option can be used to specify an 217acceptable error range in seconds, the default value is 5 minutes. 218 219If the B<notAfter> time is omitted from a response then this means that new status 220information is immediately available. In this case the age of the B<notBefore> field 221is checked to see it is not older than B<age> seconds old. By default this additional 222check is not performed. 223 224=item B<-md5|-sha1|-sha256|-ripemod160|...> 225 226this option sets digest algorithm to use for certificate identification 227in the OCSP request. By default SHA-1 is used. 228 229=back 230 231=head1 OCSP SERVER OPTIONS 232 233=over 4 234 235=item B<-index indexfile> 236 237B<indexfile> is a text index file in B<ca> format containing certificate revocation 238information. 239 240If the B<index> option is specified the B<ocsp> utility is in responder mode, otherwise 241it is in client mode. The request(s) the responder processes can be either specified on 242the command line (using B<issuer> and B<serial> options), supplied in a file (using the 243B<respin> option) or via external OCSP clients (if B<port> or B<url> is specified). 244 245If the B<index> option is present then the B<CA> and B<rsigner> options must also be 246present. 247 248=item B<-CA file> 249 250CA certificate corresponding to the revocation information in B<indexfile>. 251 252=item B<-rsigner file> 253 254The certificate to sign OCSP responses with. 255 256=item B<-rother file> 257 258Additional certificates to include in the OCSP response. 259 260=item B<-resp_no_certs> 261 262Don't include any certificates in the OCSP response. 263 264=item B<-resp_key_id> 265 266Identify the signer certificate using the key ID, default is to use the subject name. 267 268=item B<-rkey file> 269 270The private key to sign OCSP responses with: if not present the file specified in the 271B<rsigner> option is used. 272 273=item B<-port portnum> 274 275Port to listen for OCSP requests on. The port may also be specified using the B<url> 276option. 277 278=item B<-nrequest number> 279 280The OCSP server will exit after receiving B<number> requests, default unlimited. 281 282=item B<-nmin minutes>, B<-ndays days> 283 284Number of minutes or days when fresh revocation information is available: used in the 285B<nextUpdate> field. If neither option is present then the B<nextUpdate> field is 286omitted meaning fresh revocation information is immediately available. 287 288=back 289 290=head1 OCSP Response verification. 291 292OCSP Response follows the rules specified in RFC2560. 293 294Initially the OCSP responder certificate is located and the signature on 295the OCSP request checked using the responder certificate's public key. 296 297Then a normal certificate verify is performed on the OCSP responder certificate 298building up a certificate chain in the process. The locations of the trusted 299certificates used to build the chain can be specified by the B<CAfile> 300and B<CApath> options or they will be looked for in the standard OpenSSL 301certificates directory. 302 303If the initial verify fails then the OCSP verify process halts with an 304error. 305 306Otherwise the issuing CA certificate in the request is compared to the OCSP 307responder certificate: if there is a match then the OCSP verify succeeds. 308 309Otherwise the OCSP responder certificate's CA is checked against the issuing 310CA certificate in the request. If there is a match and the OCSPSigning 311extended key usage is present in the OCSP responder certificate then the 312OCSP verify succeeds. 313 314Otherwise, if B<-no_explicit> is B<not> set the root CA of the OCSP responders 315CA is checked to see if it is trusted for OCSP signing. If it is the OCSP 316verify succeeds. 317 318If none of these checks is successful then the OCSP verify fails. 319 320What this effectively means if that if the OCSP responder certificate is 321authorised directly by the CA it is issuing revocation information about 322(and it is correctly configured) then verification will succeed. 323 324If the OCSP responder is a "global responder" which can give details about 325multiple CAs and has its own separate certificate chain then its root 326CA can be trusted for OCSP signing. For example: 327 328 openssl x509 -in ocspCA.pem -addtrust OCSPSigning -out trustedCA.pem 329 330Alternatively the responder certificate itself can be explicitly trusted 331with the B<-VAfile> option. 332 333=head1 NOTES 334 335As noted, most of the verify options are for testing or debugging purposes. 336Normally only the B<-CApath>, B<-CAfile> and (if the responder is a 'global 337VA') B<-VAfile> options need to be used. 338 339The OCSP server is only useful for test and demonstration purposes: it is 340not really usable as a full OCSP responder. It contains only a very 341simple HTTP request handling and can only handle the POST form of OCSP 342queries. It also handles requests serially meaning it cannot respond to 343new requests until it has processed the current one. The text index file 344format of revocation is also inefficient for large quantities of revocation 345data. 346 347It is possible to run the B<ocsp> application in responder mode via a CGI 348script using the B<respin> and B<respout> options. 349 350=head1 EXAMPLES 351 352Create an OCSP request and write it to a file: 353 354 openssl ocsp -issuer issuer.pem -cert c1.pem -cert c2.pem -reqout req.der 355 356Send a query to an OCSP responder with URL http://ocsp.myhost.com/ save the 357response to a file and print it out in text form 358 359 openssl ocsp -issuer issuer.pem -cert c1.pem -cert c2.pem \ 360 -url http://ocsp.myhost.com/ -resp_text -respout resp.der 361 362Read in an OCSP response and print out text form: 363 364 openssl ocsp -respin resp.der -text 365 366OCSP server on port 8888 using a standard B<ca> configuration, and a separate 367responder certificate. All requests and responses are printed to a file. 368 369 openssl ocsp -index demoCA/index.txt -port 8888 -rsigner rcert.pem -CA demoCA/cacert.pem 370 -text -out log.txt 371 372As above but exit after processing one request: 373 374 openssl ocsp -index demoCA/index.txt -port 8888 -rsigner rcert.pem -CA demoCA/cacert.pem 375 -nrequest 1 376 377Query status information using internally generated request: 378 379 openssl ocsp -index demoCA/index.txt -rsigner rcert.pem -CA demoCA/cacert.pem 380 -issuer demoCA/cacert.pem -serial 1 381 382Query status information using request read from a file, write response to a 383second file. 384 385 openssl ocsp -index demoCA/index.txt -rsigner rcert.pem -CA demoCA/cacert.pem 386 -reqin req.der -respout resp.der 387 388=head1 HISTORY 389 390The -no_alt_chains options was first added to OpenSSL 1.0.1n and 1.0.2b. 391 392=cut 393