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