ocsp.pod revision 325337
1=pod 2 3=head1 NAME 4 5openssl-ocsp, 6ocsp - Online Certificate Status Protocol utility 7 8=head1 SYNOPSIS 9 10B<openssl> B<ocsp> 11[B<-out file>] 12[B<-issuer file>] 13[B<-cert file>] 14[B<-serial n>] 15[B<-signer file>] 16[B<-signkey file>] 17[B<-sign_other file>] 18[B<-no_certs>] 19[B<-req_text>] 20[B<-resp_text>] 21[B<-text>] 22[B<-reqout file>] 23[B<-respout file>] 24[B<-reqin file>] 25[B<-respin file>] 26[B<-nonce>] 27[B<-no_nonce>] 28[B<-url URL>] 29[B<-host host:n>] 30[B<-header name value>] 31[B<-path>] 32[B<-CApath dir>] 33[B<-CAfile file>] 34[B<-no_alt_chains>] 35[B<-VAfile file>] 36[B<-validity_period n>] 37[B<-status_age n>] 38[B<-noverify>] 39[B<-verify_other file>] 40[B<-trust_other>] 41[B<-no_intern>] 42[B<-no_signature_verify>] 43[B<-no_cert_verify>] 44[B<-no_chain>] 45[B<-no_cert_checks>] 46[B<-no_explicit>] 47[B<-port num>] 48[B<-index file>] 49[B<-CA file>] 50[B<-rsigner file>] 51[B<-rkey file>] 52[B<-rother file>] 53[B<-resp_no_certs>] 54[B<-nmin n>] 55[B<-ndays n>] 56[B<-resp_key_id>] 57[B<-nrequest n>] 58[B<-md5|-sha1|...>] 59 60=head1 DESCRIPTION 61 62The Online Certificate Status Protocol (OCSP) enables applications to 63determine the (revocation) state of an identified certificate (RFC 2560). 64 65The B<ocsp> command performs many common OCSP tasks. It can be used 66to print out requests and responses, create requests and send queries 67to an OCSP responder and behave like a mini OCSP server itself. 68 69=head1 OCSP CLIENT OPTIONS 70 71=over 4 72 73=item B<-out filename> 74 75specify output filename, default is standard output. 76 77=item B<-issuer filename> 78 79This specifies the current issuer certificate. This option can be used 80multiple times. The certificate specified in B<filename> must be in 81PEM format. This option B<MUST> come before any B<-cert> options. 82 83=item B<-cert filename> 84 85Add the certificate B<filename> to the request. The issuer certificate 86is taken from the previous B<issuer> option, or an error occurs if no 87issuer certificate is specified. 88 89=item B<-serial num> 90 91Same as the B<cert> option except the certificate with serial number 92B<num> is added to the request. The serial number is interpreted as a 93decimal integer unless preceded by B<0x>. Negative integers can also 94be specified by preceding the value by a B<-> sign. 95 96=item B<-signer filename>, B<-signkey filename> 97 98Sign the OCSP request using the certificate specified in the B<signer> 99option and the private key specified by the B<signkey> option. If 100the B<signkey> option is not present then the private key is read 101from the same file as the certificate. If neither option is specified then 102the OCSP request is not signed. 103 104=item B<-sign_other filename> 105 106Additional certificates to include in the signed request. 107 108=item B<-nonce>, B<-no_nonce> 109 110Add an OCSP nonce extension to a request or disable OCSP nonce addition. 111Normally if an OCSP request is input using the B<respin> option no 112nonce is added: using the B<nonce> option will force addition of a nonce. 113If an OCSP request is being created (using B<cert> and B<serial> options) 114a nonce is automatically added specifying B<no_nonce> overrides this. 115 116=item B<-req_text>, B<-resp_text>, B<-text> 117 118print out the text form of the OCSP request, response or both respectively. 119 120=item B<-reqout file>, B<-respout file> 121 122write out the DER encoded certificate request or response to B<file>. 123 124=item B<-reqin file>, B<-respin file> 125 126read OCSP request or response file from B<file>. These option are ignored 127if OCSP request or response creation is implied by other options (for example 128with B<serial>, B<cert> and B<host> options). 129 130=item B<-url responder_url> 131 132specify the responder URL. Both HTTP and HTTPS (SSL/TLS) URLs can be specified. 133 134=item B<-host hostname:port>, B<-path pathname> 135 136if the B<host> option is present then the OCSP request is sent to the host 137B<hostname> on port B<port>. B<path> specifies the HTTP path name to use 138or "/" by default. 139 140=item B<-header name value> 141 142If sending a request to an OCSP server, then the specified header name and 143value are added to the HTTP request. Note that the B<name> and B<value> must 144be specified as two separate parameters, not as a single quoted string, and 145that the header name does not have the trailing colon. 146Some OCSP responders require a Host header; use this flag to provide it. 147 148=item B<-timeout seconds> 149 150connection timeout to the OCSP responder in seconds 151 152=item B<-CAfile file>, B<-CApath pathname> 153 154file or pathname containing trusted CA certificates. These are used to verify 155the signature on the OCSP response. 156 157=item B<-no_alt_chains> 158 159See L<B<verify>|verify(1)> manual page for details. 160 161=item B<-verify_other file> 162 163file containing additional certificates to search when attempting to locate 164the OCSP response signing certificate. Some responders omit the actual signer's 165certificate from the response: this option can be used to supply the necessary 166certificate in such cases. 167 168=item B<-trust_other> 169 170the certificates specified by the B<-verify_other> option should be explicitly 171trusted and no additional checks will be performed on them. This is useful 172when the complete responder certificate chain is not available or trusting a 173root CA is not appropriate. 174 175=item B<-VAfile file> 176 177file containing explicitly trusted responder certificates. Equivalent to the 178B<-verify_other> and B<-trust_other> options. 179 180=item B<-noverify> 181 182don't attempt to verify the OCSP response signature or the nonce values. This 183option will normally only be used for debugging since it disables all verification 184of the responders certificate. 185 186=item B<-no_intern> 187 188ignore certificates contained in the OCSP response when searching for the 189signers certificate. With this option the signers certificate must be specified 190with either the B<-verify_other> or B<-VAfile> options. 191 192=item B<-no_signature_verify> 193 194don't check the signature on the OCSP response. Since this option tolerates invalid 195signatures on OCSP responses it will normally only be used for testing purposes. 196 197=item B<-no_cert_verify> 198 199don't verify the OCSP response signers certificate at all. Since this option allows 200the OCSP response to be signed by any certificate it should only be used for 201testing purposes. 202 203=item B<-no_chain> 204 205do not use certificates in the response as additional untrusted CA 206certificates. 207 208=item B<-no_explicit> 209 210do not explicitly trust the root CA if it is set to be trusted for OCSP signing. 211 212=item B<-no_cert_checks> 213 214don't perform any additional checks on the OCSP response signers certificate. 215That is do not make any checks to see if the signers certificate is authorised 216to provide the necessary status information: as a result this option should 217only be used for testing purposes. 218 219=item B<-validity_period nsec>, B<-status_age age> 220 221these options specify the range of times, in seconds, which will be tolerated 222in an OCSP response. Each certificate status response includes a B<notBefore> time and 223an optional B<notAfter> time. The current time should fall between these two values, but 224the interval between the two times may be only a few seconds. In practice the OCSP 225responder and clients clocks may not be precisely synchronised and so such a check 226may fail. To avoid this the B<-validity_period> option can be used to specify an 227acceptable error range in seconds, the default value is 5 minutes. 228 229If the B<notAfter> time is omitted from a response then this means that new status 230information is immediately available. In this case the age of the B<notBefore> field 231is checked to see it is not older than B<age> seconds old. By default this additional 232check is not performed. 233 234=item B<-md5|-sha1|-sha256|-ripemod160|...> 235 236this option sets digest algorithm to use for certificate identification 237in the OCSP request. By default SHA-1 is used. 238 239=back 240 241=head1 OCSP SERVER OPTIONS 242 243=over 4 244 245=item B<-index indexfile> 246 247B<indexfile> is a text index file in B<ca> format containing certificate revocation 248information. 249 250If the B<index> option is specified the B<ocsp> utility is in responder mode, otherwise 251it is in client mode. The request(s) the responder processes can be either specified on 252the command line (using B<issuer> and B<serial> options), supplied in a file (using the 253B<respin> option) or via external OCSP clients (if B<port> or B<url> is specified). 254 255If the B<index> option is present then the B<CA> and B<rsigner> options must also be 256present. 257 258=item B<-CA file> 259 260CA certificate corresponding to the revocation information in B<indexfile>. 261 262=item B<-rsigner file> 263 264The certificate to sign OCSP responses with. 265 266=item B<-rother file> 267 268Additional certificates to include in the OCSP response. 269 270=item B<-resp_no_certs> 271 272Don't include any certificates in the OCSP response. 273 274=item B<-resp_key_id> 275 276Identify the signer certificate using the key ID, default is to use the subject name. 277 278=item B<-rkey file> 279 280The private key to sign OCSP responses with: if not present the file specified in the 281B<rsigner> option is used. 282 283=item B<-port portnum> 284 285Port to listen for OCSP requests on. The port may also be specified using the B<url> 286option. 287 288=item B<-nrequest number> 289 290The OCSP server will exit after receiving B<number> requests, default unlimited. 291 292=item B<-nmin minutes>, B<-ndays days> 293 294Number of minutes or days when fresh revocation information is available: used in the 295B<nextUpdate> field. If neither option is present then the B<nextUpdate> field is 296omitted meaning fresh revocation information is immediately available. 297 298=back 299 300=head1 OCSP Response verification. 301 302OCSP Response follows the rules specified in RFC2560. 303 304Initially the OCSP responder certificate is located and the signature on 305the OCSP request checked using the responder certificate's public key. 306 307Then a normal certificate verify is performed on the OCSP responder certificate 308building up a certificate chain in the process. The locations of the trusted 309certificates used to build the chain can be specified by the B<CAfile> 310and B<CApath> options or they will be looked for in the standard OpenSSL 311certificates directory. 312 313If the initial verify fails then the OCSP verify process halts with an 314error. 315 316Otherwise the issuing CA certificate in the request is compared to the OCSP 317responder certificate: if there is a match then the OCSP verify succeeds. 318 319Otherwise the OCSP responder certificate's CA is checked against the issuing 320CA certificate in the request. If there is a match and the OCSPSigning 321extended key usage is present in the OCSP responder certificate then the 322OCSP verify succeeds. 323 324Otherwise, if B<-no_explicit> is B<not> set the root CA of the OCSP responders 325CA is checked to see if it is trusted for OCSP signing. If it is the OCSP 326verify succeeds. 327 328If none of these checks is successful then the OCSP verify fails. 329 330What this effectively means if that if the OCSP responder certificate is 331authorised directly by the CA it is issuing revocation information about 332(and it is correctly configured) then verification will succeed. 333 334If the OCSP responder is a "global responder" which can give details about 335multiple CAs and has its own separate certificate chain then its root 336CA can be trusted for OCSP signing. For example: 337 338 openssl x509 -in ocspCA.pem -addtrust OCSPSigning -out trustedCA.pem 339 340Alternatively the responder certificate itself can be explicitly trusted 341with the B<-VAfile> option. 342 343=head1 NOTES 344 345As noted, most of the verify options are for testing or debugging purposes. 346Normally only the B<-CApath>, B<-CAfile> and (if the responder is a 'global 347VA') B<-VAfile> options need to be used. 348 349The OCSP server is only useful for test and demonstration purposes: it is 350not really usable as a full OCSP responder. It contains only a very 351simple HTTP request handling and can only handle the POST form of OCSP 352queries. It also handles requests serially meaning it cannot respond to 353new requests until it has processed the current one. The text index file 354format of revocation is also inefficient for large quantities of revocation 355data. 356 357It is possible to run the B<ocsp> application in responder mode via a CGI 358script using the B<respin> and B<respout> options. 359 360=head1 EXAMPLES 361 362Create an OCSP request and write it to a file: 363 364 openssl ocsp -issuer issuer.pem -cert c1.pem -cert c2.pem -reqout req.der 365 366Send a query to an OCSP responder with URL http://ocsp.myhost.com/ save the 367response to a file and print it out in text form 368 369 openssl ocsp -issuer issuer.pem -cert c1.pem -cert c2.pem \ 370 -url http://ocsp.myhost.com/ -resp_text -respout resp.der 371 372Read in an OCSP response and print out text form: 373 374 openssl ocsp -respin resp.der -text 375 376OCSP server on port 8888 using a standard B<ca> configuration, and a separate 377responder certificate. All requests and responses are printed to a file. 378 379 openssl ocsp -index demoCA/index.txt -port 8888 -rsigner rcert.pem -CA demoCA/cacert.pem 380 -text -out log.txt 381 382As above but exit after processing one request: 383 384 openssl ocsp -index demoCA/index.txt -port 8888 -rsigner rcert.pem -CA demoCA/cacert.pem 385 -nrequest 1 386 387Query status information using internally generated request: 388 389 openssl ocsp -index demoCA/index.txt -rsigner rcert.pem -CA demoCA/cacert.pem 390 -issuer demoCA/cacert.pem -serial 1 391 392Query status information using request read from a file, write response to a 393second file. 394 395 openssl ocsp -index demoCA/index.txt -rsigner rcert.pem -CA demoCA/cacert.pem 396 -reqin req.der -respout resp.der 397 398=head1 HISTORY 399 400The -no_alt_chains options was first added to OpenSSL 1.0.2b. 401 402=cut 403