ocsp.pod revision 312826
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<-header name value>] 30[B<-path>] 31[B<-CApath dir>] 32[B<-CAfile file>] 33[B<-no_alt_chains>] 34[B<-VAfile file>] 35[B<-validity_period n>] 36[B<-status_age n>] 37[B<-noverify>] 38[B<-verify_other file>] 39[B<-trust_other>] 40[B<-no_intern>] 41[B<-no_signature_verify>] 42[B<-no_cert_verify>] 43[B<-no_chain>] 44[B<-no_cert_checks>] 45[B<-no_explicit>] 46[B<-port num>] 47[B<-index file>] 48[B<-CA file>] 49[B<-rsigner file>] 50[B<-rkey file>] 51[B<-rother file>] 52[B<-resp_no_certs>] 53[B<-nmin n>] 54[B<-ndays n>] 55[B<-resp_key_id>] 56[B<-nrequest n>] 57[B<-md5|-sha1|...>] 58 59=head1 DESCRIPTION 60 61The Online Certificate Status Protocol (OCSP) enables applications to 62determine the (revocation) state of an identified certificate (RFC 2560). 63 64The B<ocsp> command performs many common OCSP tasks. It can be used 65to print out requests and responses, create requests and send queries 66to an OCSP responder and behave like a mini OCSP server itself. 67 68=head1 OCSP CLIENT OPTIONS 69 70=over 4 71 72=item B<-out filename> 73 74specify output filename, default is standard output. 75 76=item B<-issuer filename> 77 78This specifies the current issuer certificate. This option can be used 79multiple times. The certificate specified in B<filename> must be in 80PEM format. This option B<MUST> come before any B<-cert> options. 81 82=item B<-cert filename> 83 84Add the certificate B<filename> to the request. The issuer certificate 85is taken from the previous B<issuer> option, or an error occurs if no 86issuer certificate is specified. 87 88=item B<-serial num> 89 90Same as the B<cert> option except the certificate with serial number 91B<num> is added to the request. The serial number is interpreted as a 92decimal integer unless preceded by B<0x>. Negative integers can also 93be specified by preceding the value by a B<-> sign. 94 95=item B<-signer filename>, B<-signkey filename> 96 97Sign the OCSP request using the certificate specified in the B<signer> 98option and the private key specified by the B<signkey> option. If 99the B<signkey> option is not present then the private key is read 100from the same file as the certificate. If neither option is specified then 101the OCSP request is not signed. 102 103=item B<-sign_other filename> 104 105Additional certificates to include in the signed request. 106 107=item B<-nonce>, B<-no_nonce> 108 109Add an OCSP nonce extension to a request or disable OCSP nonce addition. 110Normally if an OCSP request is input using the B<respin> option no 111nonce is added: using the B<nonce> option will force addition of a nonce. 112If an OCSP request is being created (using B<cert> and B<serial> options) 113a nonce is automatically added specifying B<no_nonce> overrides this. 114 115=item B<-req_text>, B<-resp_text>, B<-text> 116 117print out the text form of the OCSP request, response or both respectively. 118 119=item B<-reqout file>, B<-respout file> 120 121write out the DER encoded certificate request or response to B<file>. 122 123=item B<-reqin file>, B<-respin file> 124 125read OCSP request or response file from B<file>. These option are ignored 126if OCSP request or response creation is implied by other options (for example 127with B<serial>, B<cert> and B<host> options). 128 129=item B<-url responder_url> 130 131specify the responder URL. Both HTTP and HTTPS (SSL/TLS) URLs can be specified. 132 133=item B<-host hostname:port>, B<-path pathname> 134 135if the B<host> option is present then the OCSP request is sent to the host 136B<hostname> on port B<port>. B<path> specifies the HTTP path name to use 137or "/" by default. 138 139=item B<-header name value> 140 141If sending a request to an OCSP server, then the specified header name and 142value are added to the HTTP request. Note that the B<name> and B<value> must 143be specified as two separate parameters, not as a single quoted string, and 144that the header name does not have the trailing colon. 145Some OCSP responders require a Host header; use this flag to provide it. 146 147=item B<-timeout seconds> 148 149connection timeout to the OCSP responder in seconds 150 151=item B<-CAfile file>, B<-CApath pathname> 152 153file or pathname containing trusted CA certificates. These are used to verify 154the signature on the OCSP response. 155 156=item B<-no_alt_chains> 157 158See L<B<verify>|verify(1)> manual page for details. 159 160=item B<-verify_other file> 161 162file containing additional certificates to search when attempting to locate 163the OCSP response signing certificate. Some responders omit the actual signer's 164certificate from the response: this option can be used to supply the necessary 165certificate in such cases. 166 167=item B<-trust_other> 168 169the certificates specified by the B<-verify_other> option should be explicitly 170trusted and no additional checks will be performed on them. This is useful 171when the complete responder certificate chain is not available or trusting a 172root CA is not appropriate. 173 174=item B<-VAfile file> 175 176file containing explicitly trusted responder certificates. Equivalent to the 177B<-verify_other> and B<-trust_other> options. 178 179=item B<-noverify> 180 181don't attempt to verify the OCSP response signature or the nonce values. This 182option will normally only be used for debugging since it disables all verification 183of the responders certificate. 184 185=item B<-no_intern> 186 187ignore certificates contained in the OCSP response when searching for the 188signers certificate. With this option the signers certificate must be specified 189with either the B<-verify_other> or B<-VAfile> options. 190 191=item B<-no_signature_verify> 192 193don't check the signature on the OCSP response. Since this option tolerates invalid 194signatures on OCSP responses it will normally only be used for testing purposes. 195 196=item B<-no_cert_verify> 197 198don't verify the OCSP response signers certificate at all. Since this option allows 199the OCSP response to be signed by any certificate it should only be used for 200testing purposes. 201 202=item B<-no_chain> 203 204do not use certificates in the response as additional untrusted CA 205certificates. 206 207=item B<-no_explicit> 208 209do not explicitly trust the root CA if it is set to be trusted for OCSP signing. 210 211=item B<-no_cert_checks> 212 213don't perform any additional checks on the OCSP response signers certificate. 214That is do not make any checks to see if the signers certificate is authorised 215to provide the necessary status information: as a result this option should 216only be used for testing purposes. 217 218=item B<-validity_period nsec>, B<-status_age age> 219 220these options specify the range of times, in seconds, which will be tolerated 221in an OCSP response. Each certificate status response includes a B<notBefore> time and 222an optional B<notAfter> time. The current time should fall between these two values, but 223the interval between the two times may be only a few seconds. In practice the OCSP 224responder and clients clocks may not be precisely synchronised and so such a check 225may fail. To avoid this the B<-validity_period> option can be used to specify an 226acceptable error range in seconds, the default value is 5 minutes. 227 228If the B<notAfter> time is omitted from a response then this means that new status 229information is immediately available. In this case the age of the B<notBefore> field 230is checked to see it is not older than B<age> seconds old. By default this additional 231check is not performed. 232 233=item B<-md5|-sha1|-sha256|-ripemod160|...> 234 235this option sets digest algorithm to use for certificate identification 236in the OCSP request. By default SHA-1 is used. 237 238=back 239 240=head1 OCSP SERVER OPTIONS 241 242=over 4 243 244=item B<-index indexfile> 245 246B<indexfile> is a text index file in B<ca> format containing certificate revocation 247information. 248 249If the B<index> option is specified the B<ocsp> utility is in responder mode, otherwise 250it is in client mode. The request(s) the responder processes can be either specified on 251the command line (using B<issuer> and B<serial> options), supplied in a file (using the 252B<respin> option) or via external OCSP clients (if B<port> or B<url> is specified). 253 254If the B<index> option is present then the B<CA> and B<rsigner> options must also be 255present. 256 257=item B<-CA file> 258 259CA certificate corresponding to the revocation information in B<indexfile>. 260 261=item B<-rsigner file> 262 263The certificate to sign OCSP responses with. 264 265=item B<-rother file> 266 267Additional certificates to include in the OCSP response. 268 269=item B<-resp_no_certs> 270 271Don't include any certificates in the OCSP response. 272 273=item B<-resp_key_id> 274 275Identify the signer certificate using the key ID, default is to use the subject name. 276 277=item B<-rkey file> 278 279The private key to sign OCSP responses with: if not present the file specified in the 280B<rsigner> option is used. 281 282=item B<-port portnum> 283 284Port to listen for OCSP requests on. The port may also be specified using the B<url> 285option. 286 287=item B<-nrequest number> 288 289The OCSP server will exit after receiving B<number> requests, default unlimited. 290 291=item B<-nmin minutes>, B<-ndays days> 292 293Number of minutes or days when fresh revocation information is available: used in the 294B<nextUpdate> field. If neither option is present then the B<nextUpdate> field is 295omitted meaning fresh revocation information is immediately available. 296 297=back 298 299=head1 OCSP Response verification. 300 301OCSP Response follows the rules specified in RFC2560. 302 303Initially the OCSP responder certificate is located and the signature on 304the OCSP request checked using the responder certificate's public key. 305 306Then a normal certificate verify is performed on the OCSP responder certificate 307building up a certificate chain in the process. The locations of the trusted 308certificates used to build the chain can be specified by the B<CAfile> 309and B<CApath> options or they will be looked for in the standard OpenSSL 310certificates directory. 311 312If the initial verify fails then the OCSP verify process halts with an 313error. 314 315Otherwise the issuing CA certificate in the request is compared to the OCSP 316responder certificate: if there is a match then the OCSP verify succeeds. 317 318Otherwise the OCSP responder certificate's CA is checked against the issuing 319CA certificate in the request. If there is a match and the OCSPSigning 320extended key usage is present in the OCSP responder certificate then the 321OCSP verify succeeds. 322 323Otherwise, if B<-no_explicit> is B<not> set the root CA of the OCSP responders 324CA is checked to see if it is trusted for OCSP signing. If it is the OCSP 325verify succeeds. 326 327If none of these checks is successful then the OCSP verify fails. 328 329What this effectively means if that if the OCSP responder certificate is 330authorised directly by the CA it is issuing revocation information about 331(and it is correctly configured) then verification will succeed. 332 333If the OCSP responder is a "global responder" which can give details about 334multiple CAs and has its own separate certificate chain then its root 335CA can be trusted for OCSP signing. For example: 336 337 openssl x509 -in ocspCA.pem -addtrust OCSPSigning -out trustedCA.pem 338 339Alternatively the responder certificate itself can be explicitly trusted 340with the B<-VAfile> option. 341 342=head1 NOTES 343 344As noted, most of the verify options are for testing or debugging purposes. 345Normally only the B<-CApath>, B<-CAfile> and (if the responder is a 'global 346VA') B<-VAfile> options need to be used. 347 348The OCSP server is only useful for test and demonstration purposes: it is 349not really usable as a full OCSP responder. It contains only a very 350simple HTTP request handling and can only handle the POST form of OCSP 351queries. It also handles requests serially meaning it cannot respond to 352new requests until it has processed the current one. The text index file 353format of revocation is also inefficient for large quantities of revocation 354data. 355 356It is possible to run the B<ocsp> application in responder mode via a CGI 357script using the B<respin> and B<respout> options. 358 359=head1 EXAMPLES 360 361Create an OCSP request and write it to a file: 362 363 openssl ocsp -issuer issuer.pem -cert c1.pem -cert c2.pem -reqout req.der 364 365Send a query to an OCSP responder with URL http://ocsp.myhost.com/ save the 366response to a file and print it out in text form 367 368 openssl ocsp -issuer issuer.pem -cert c1.pem -cert c2.pem \ 369 -url http://ocsp.myhost.com/ -resp_text -respout resp.der 370 371Read in an OCSP response and print out text form: 372 373 openssl ocsp -respin resp.der -text 374 375OCSP server on port 8888 using a standard B<ca> configuration, and a separate 376responder certificate. All requests and responses are printed to a file. 377 378 openssl ocsp -index demoCA/index.txt -port 8888 -rsigner rcert.pem -CA demoCA/cacert.pem 379 -text -out log.txt 380 381As above but exit after processing one request: 382 383 openssl ocsp -index demoCA/index.txt -port 8888 -rsigner rcert.pem -CA demoCA/cacert.pem 384 -nrequest 1 385 386Query status information using internally generated request: 387 388 openssl ocsp -index demoCA/index.txt -rsigner rcert.pem -CA demoCA/cacert.pem 389 -issuer demoCA/cacert.pem -serial 1 390 391Query status information using request read from a file, write response to a 392second file. 393 394 openssl ocsp -index demoCA/index.txt -rsigner rcert.pem -CA demoCA/cacert.pem 395 -reqin req.der -respout resp.der 396 397=head1 HISTORY 398 399The -no_alt_chains options was first added to OpenSSL 1.0.2b. 400 401=cut 402