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