ca.pod revision 111147
1 2=pod 3 4=head1 NAME 5 6ca - sample minimal CA application 7 8=head1 SYNOPSIS 9 10B<openssl> B<ca> 11[B<-verbose>] 12[B<-config filename>] 13[B<-name section>] 14[B<-gencrl>] 15[B<-revoke file>] 16[B<-crl_reason reason>] 17[B<-crl_hold instruction>] 18[B<-crl_compromise time>] 19[B<-crl_CA_compromise time>] 20[B<-subj arg>] 21[B<-crldays days>] 22[B<-crlhours hours>] 23[B<-crlexts section>] 24[B<-startdate date>] 25[B<-enddate date>] 26[B<-days arg>] 27[B<-md arg>] 28[B<-policy arg>] 29[B<-keyfile arg>] 30[B<-key arg>] 31[B<-passin arg>] 32[B<-cert file>] 33[B<-in file>] 34[B<-out file>] 35[B<-notext>] 36[B<-outdir dir>] 37[B<-infiles>] 38[B<-spkac file>] 39[B<-ss_cert file>] 40[B<-preserveDN>] 41[B<-noemailDN>] 42[B<-batch>] 43[B<-msie_hack>] 44[B<-extensions section>] 45[B<-extfile section>] 46[B<-engine id>] 47 48=head1 DESCRIPTION 49 50The B<ca> command is a minimal CA application. It can be used 51to sign certificate requests in a variety of forms and generate 52CRLs it also maintains a text database of issued certificates 53and their status. 54 55The options descriptions will be divided into each purpose. 56 57=head1 CA OPTIONS 58 59=over 4 60 61=item B<-config filename> 62 63specifies the configuration file to use. 64 65=item B<-name section> 66 67specifies the configuration file section to use (overrides 68B<default_ca> in the B<ca> section). 69 70=item B<-in filename> 71 72an input filename containing a single certificate request to be 73signed by the CA. 74 75=item B<-ss_cert filename> 76 77a single self signed certificate to be signed by the CA. 78 79=item B<-spkac filename> 80 81a file containing a single Netscape signed public key and challenge 82and additional field values to be signed by the CA. See the B<SPKAC FORMAT> 83section for information on the required format. 84 85=item B<-infiles> 86 87if present this should be the last option, all subsequent arguments 88are assumed to the the names of files containing certificate requests. 89 90=item B<-out filename> 91 92the output file to output certificates to. The default is standard 93output. The certificate details will also be printed out to this 94file. 95 96=item B<-outdir directory> 97 98the directory to output certificates to. The certificate will be 99written to a filename consisting of the serial number in hex with 100".pem" appended. 101 102=item B<-cert> 103 104the CA certificate file. 105 106=item B<-keyfile filename> 107 108the private key to sign requests with. 109 110=item B<-key password> 111 112the password used to encrypt the private key. Since on some 113systems the command line arguments are visible (e.g. Unix with 114the 'ps' utility) this option should be used with caution. 115 116=item B<-passin arg> 117 118the key password source. For more information about the format of B<arg> 119see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>. 120 121=item B<-verbose> 122 123this prints extra details about the operations being performed. 124 125=item B<-notext> 126 127don't output the text form of a certificate to the output file. 128 129=item B<-startdate date> 130 131this allows the start date to be explicitly set. The format of the 132date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure). 133 134=item B<-enddate date> 135 136this allows the expiry date to be explicitly set. The format of the 137date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure). 138 139=item B<-days arg> 140 141the number of days to certify the certificate for. 142 143=item B<-md alg> 144 145the message digest to use. Possible values include md5, sha1 and mdc2. 146This option also applies to CRLs. 147 148=item B<-policy arg> 149 150this option defines the CA "policy" to use. This is a section in 151the configuration file which decides which fields should be mandatory 152or match the CA certificate. Check out the B<POLICY FORMAT> section 153for more information. 154 155=item B<-msie_hack> 156 157this is a legacy option to make B<ca> work with very old versions of 158the IE certificate enrollment control "certenr3". It used UniversalStrings 159for almost everything. Since the old control has various security bugs 160its use is strongly discouraged. The newer control "Xenroll" does not 161need this option. 162 163=item B<-preserveDN> 164 165Normally the DN order of a certificate is the same as the order of the 166fields in the relevant policy section. When this option is set the order 167is the same as the request. This is largely for compatibility with the 168older IE enrollment control which would only accept certificates if their 169DNs match the order of the request. This is not needed for Xenroll. 170 171=item B<-noemailDN> 172 173The DN of a certificate can contain the EMAIL field if present in the 174request DN, however it is good policy just having the e-mail set into 175the altName extension of the certificate. When this option is set the 176EMAIL field is removed from the certificate' subject and set only in 177the, eventually present, extensions. The B<email_in_dn> keyword can be 178used in the configuration file to enable this behaviour. 179 180=item B<-batch> 181 182this sets the batch mode. In this mode no questions will be asked 183and all certificates will be certified automatically. 184 185=item B<-extensions section> 186 187the section of the configuration file containing certificate extensions 188to be added when a certificate is issued (defaults to B<x509_extensions> 189unless the B<-extfile> option is used). If no extension section is 190present then, a V1 certificate is created. If the extension section 191is present (even if it is empty), then a V3 certificate is created. 192 193=item B<-extfile file> 194 195an additional configuration file to read certificate extensions from 196(using the default section unless the B<-extensions> option is also 197used). 198 199=item B<-engine id> 200 201specifying an engine (by it's unique B<id> string) will cause B<req> 202to attempt to obtain a functional reference to the specified engine, 203thus initialising it if needed. The engine will then be set as the default 204for all available algorithms. 205 206=back 207 208=head1 CRL OPTIONS 209 210=over 4 211 212=item B<-gencrl> 213 214this option generates a CRL based on information in the index file. 215 216=item B<-crldays num> 217 218the number of days before the next CRL is due. That is the days from 219now to place in the CRL nextUpdate field. 220 221=item B<-crlhours num> 222 223the number of hours before the next CRL is due. 224 225=item B<-revoke filename> 226 227a filename containing a certificate to revoke. 228 229=item B<-crl_reason reason> 230 231revocation reason, where B<reason> is one of: B<unspecified>, B<keyCompromise>, 232B<CACompromise>, B<affiliationChanged>, B<superseded>, B<cessationOfOperation>, 233B<certificateHold> or B<removeFromCRL>. The matching of B<reason> is case 234insensitive. Setting any revocation reason will make the CRL v2. 235 236In practive B<removeFromCRL> is not particularly useful because it is only used 237in delta CRLs which are not currently implemented. 238 239=item B<-crl_hold instruction> 240 241This sets the CRL revocation reason code to B<certificateHold> and the hold 242instruction to B<instruction> which must be an OID. Although any OID can be 243used only B<holdInstructionNone> (the use of which is discouraged by RFC2459) 244B<holdInstructionCallIssuer> or B<holdInstructionReject> will normally be used. 245 246=item B<-crl_compromise time> 247 248This sets the revocation reason to B<keyCompromise> and the compromise time to 249B<time>. B<time> should be in GeneralizedTime format that is B<YYYYMMDDHHMMSSZ>. 250 251=item B<-crl_CA_compromise time> 252 253This is the same as B<crl_compromise> except the revocation reason is set to 254B<CACompromise>. 255 256=item B<-subj arg> 257 258supersedes subject name given in the request. 259The arg must be formatted as I</type0=value0/type1=value1/type2=...>, 260characters may be escaped by \ (backslash), no spaces are skipped. 261 262=item B<-crlexts section> 263 264the section of the configuration file containing CRL extensions to 265include. If no CRL extension section is present then a V1 CRL is 266created, if the CRL extension section is present (even if it is 267empty) then a V2 CRL is created. The CRL extensions specified are 268CRL extensions and B<not> CRL entry extensions. It should be noted 269that some software (for example Netscape) can't handle V2 CRLs. 270 271=back 272 273=head1 CONFIGURATION FILE OPTIONS 274 275The section of the configuration file containing options for B<ca> 276is found as follows: If the B<-name> command line option is used, 277then it names the section to be used. Otherwise the section to 278be used must be named in the B<default_ca> option of the B<ca> section 279of the configuration file (or in the default section of the 280configuration file). Besides B<default_ca>, the following options are 281read directly from the B<ca> section: 282 RANDFILE 283 preserve 284 msie_hack 285With the exception of B<RANDFILE>, this is probably a bug and may 286change in future releases. 287 288Many of the configuration file options are identical to command line 289options. Where the option is present in the configuration file 290and the command line the command line value is used. Where an 291option is described as mandatory then it must be present in 292the configuration file or the command line equivalent (if 293any) used. 294 295=over 4 296 297=item B<oid_file> 298 299This specifies a file containing additional B<OBJECT IDENTIFIERS>. 300Each line of the file should consist of the numerical form of the 301object identifier followed by white space then the short name followed 302by white space and finally the long name. 303 304=item B<oid_section> 305 306This specifies a section in the configuration file containing extra 307object identifiers. Each line should consist of the short name of the 308object identifier followed by B<=> and the numerical form. The short 309and long names are the same when this option is used. 310 311=item B<new_certs_dir> 312 313the same as the B<-outdir> command line option. It specifies 314the directory where new certificates will be placed. Mandatory. 315 316=item B<certificate> 317 318the same as B<-cert>. It gives the file containing the CA 319certificate. Mandatory. 320 321=item B<private_key> 322 323same as the B<-keyfile> option. The file containing the 324CA private key. Mandatory. 325 326=item B<RANDFILE> 327 328a file used to read and write random number seed information, or 329an EGD socket (see L<RAND_egd(3)|RAND_egd(3)>). 330 331=item B<default_days> 332 333the same as the B<-days> option. The number of days to certify 334a certificate for. 335 336=item B<default_startdate> 337 338the same as the B<-startdate> option. The start date to certify 339a certificate for. If not set the current time is used. 340 341=item B<default_enddate> 342 343the same as the B<-enddate> option. Either this option or 344B<default_days> (or the command line equivalents) must be 345present. 346 347=item B<default_crl_hours default_crl_days> 348 349the same as the B<-crlhours> and the B<-crldays> options. These 350will only be used if neither command line option is present. At 351least one of these must be present to generate a CRL. 352 353=item B<default_md> 354 355the same as the B<-md> option. The message digest to use. Mandatory. 356 357=item B<database> 358 359the text database file to use. Mandatory. This file must be present 360though initially it will be empty. 361 362=item B<serialfile> 363 364a text file containing the next serial number to use in hex. Mandatory. 365This file must be present and contain a valid serial number. 366 367=item B<x509_extensions> 368 369the same as B<-extensions>. 370 371=item B<crl_extensions> 372 373the same as B<-crlexts>. 374 375=item B<preserve> 376 377the same as B<-preserveDN> 378 379=item B<email_in_dn> 380 381the same as B<-noemailDN>. If you want the EMAIL field to be removed 382from the DN of the certificate simply set this to 'no'. If not present 383the default is to allow for the EMAIL filed in the certificate's DN. 384 385=item B<msie_hack> 386 387the same as B<-msie_hack> 388 389=item B<policy> 390 391the same as B<-policy>. Mandatory. See the B<POLICY FORMAT> section 392for more information. 393 394=item B<nameopt>, B<certopt> 395 396these options allow the format used to display the certificate details 397when asking the user to confirm signing. All the options supported by 398the B<x509> utilities B<-nameopt> and B<-certopt> switches can be used 399here, except the B<no_signame> and B<no_sigdump> are permanently set 400and cannot be disabled (this is because the certificate signature cannot 401be displayed because the certificate has not been signed at this point). 402 403For convenience the values B<default_ca> are accepted by both to produce 404a reasonable output. 405 406If neither option is present the format used in earlier versions of 407OpenSSL is used. Use of the old format is B<strongly> discouraged because 408it only displays fields mentioned in the B<policy> section, mishandles 409multicharacter string types and does not display extensions. 410 411=item B<copy_extensions> 412 413determines how extensions in certificate requests should be handled. 414If set to B<none> or this option is not present then extensions are 415ignored and not copied to the certificate. If set to B<copy> then any 416extensions present in the request that are not already present are copied 417to the certificate. If set to B<copyall> then all extensions in the 418request are copied to the certificate: if the extension is already present 419in the certificate it is deleted first. See the B<WARNINGS> section before 420using this option. 421 422The main use of this option is to allow a certificate request to supply 423values for certain extensions such as subjectAltName. 424 425=back 426 427=head1 POLICY FORMAT 428 429The policy section consists of a set of variables corresponding to 430certificate DN fields. If the value is "match" then the field value 431must match the same field in the CA certificate. If the value is 432"supplied" then it must be present. If the value is "optional" then 433it may be present. Any fields not mentioned in the policy section 434are silently deleted, unless the B<-preserveDN> option is set but 435this can be regarded more of a quirk than intended behaviour. 436 437=head1 SPKAC FORMAT 438 439The input to the B<-spkac> command line option is a Netscape 440signed public key and challenge. This will usually come from 441the B<KEYGEN> tag in an HTML form to create a new private key. 442It is however possible to create SPKACs using the B<spkac> utility. 443 444The file should contain the variable SPKAC set to the value of 445the SPKAC and also the required DN components as name value pairs. 446If you need to include the same component twice then it can be 447preceded by a number and a '.'. 448 449=head1 EXAMPLES 450 451Note: these examples assume that the B<ca> directory structure is 452already set up and the relevant files already exist. This usually 453involves creating a CA certificate and private key with B<req>, a 454serial number file and an empty index file and placing them in 455the relevant directories. 456 457To use the sample configuration file below the directories demoCA, 458demoCA/private and demoCA/newcerts would be created. The CA 459certificate would be copied to demoCA/cacert.pem and its private 460key to demoCA/private/cakey.pem. A file demoCA/serial would be 461created containing for example "01" and the empty index file 462demoCA/index.txt. 463 464 465Sign a certificate request: 466 467 openssl ca -in req.pem -out newcert.pem 468 469Sign a certificate request, using CA extensions: 470 471 openssl ca -in req.pem -extensions v3_ca -out newcert.pem 472 473Generate a CRL 474 475 openssl ca -gencrl -out crl.pem 476 477Sign several requests: 478 479 openssl ca -infiles req1.pem req2.pem req3.pem 480 481Certify a Netscape SPKAC: 482 483 openssl ca -spkac spkac.txt 484 485A sample SPKAC file (the SPKAC line has been truncated for clarity): 486 487 SPKAC=MIG0MGAwXDANBgkqhkiG9w0BAQEFAANLADBIAkEAn7PDhCeV/xIxUg8V70YRxK2A5 488 CN=Steve Test 489 emailAddress=steve@openssl.org 490 0.OU=OpenSSL Group 491 1.OU=Another Group 492 493A sample configuration file with the relevant sections for B<ca>: 494 495 [ ca ] 496 default_ca = CA_default # The default ca section 497 498 [ CA_default ] 499 500 dir = ./demoCA # top dir 501 database = $dir/index.txt # index file. 502 new_certs_dir = $dir/newcerts # new certs dir 503 504 certificate = $dir/cacert.pem # The CA cert 505 serial = $dir/serial # serial no file 506 private_key = $dir/private/cakey.pem# CA private key 507 RANDFILE = $dir/private/.rand # random number file 508 509 default_days = 365 # how long to certify for 510 default_crl_days= 30 # how long before next CRL 511 default_md = md5 # md to use 512 513 policy = policy_any # default policy 514 email_in_dn = no # Don't add the email into cert DN 515 516 nameopt = default_ca # Subject name display option 517 certopt = default_ca # Certificate display option 518 copy_extensions = none # Don't copy extensions from request 519 520 [ policy_any ] 521 countryName = supplied 522 stateOrProvinceName = optional 523 organizationName = optional 524 organizationalUnitName = optional 525 commonName = supplied 526 emailAddress = optional 527 528=head1 FILES 529 530Note: the location of all files can change either by compile time options, 531configuration file entries, environment variables or command line options. 532The values below reflect the default values. 533 534 /usr/local/ssl/lib/openssl.cnf - master configuration file 535 ./demoCA - main CA directory 536 ./demoCA/cacert.pem - CA certificate 537 ./demoCA/private/cakey.pem - CA private key 538 ./demoCA/serial - CA serial number file 539 ./demoCA/serial.old - CA serial number backup file 540 ./demoCA/index.txt - CA text database file 541 ./demoCA/index.txt.old - CA text database backup file 542 ./demoCA/certs - certificate output file 543 ./demoCA/.rnd - CA random seed information 544 545=head1 ENVIRONMENT VARIABLES 546 547B<OPENSSL_CONF> reflects the location of master configuration file it can 548be overridden by the B<-config> command line option. 549 550=head1 RESTRICTIONS 551 552The text database index file is a critical part of the process and 553if corrupted it can be difficult to fix. It is theoretically possible 554to rebuild the index file from all the issued certificates and a current 555CRL: however there is no option to do this. 556 557V2 CRL features like delta CRL support and CRL numbers are not currently 558supported. 559 560Although several requests can be input and handled at once it is only 561possible to include one SPKAC or self signed certificate. 562 563=head1 BUGS 564 565The use of an in memory text database can cause problems when large 566numbers of certificates are present because, as the name implies 567the database has to be kept in memory. 568 569It is not possible to certify two certificates with the same DN: this 570is a side effect of how the text database is indexed and it cannot easily 571be fixed without introducing other problems. Some S/MIME clients can use 572two certificates with the same DN for separate signing and encryption 573keys. 574 575The B<ca> command really needs rewriting or the required functionality 576exposed at either a command or interface level so a more friendly utility 577(perl script or GUI) can handle things properly. The scripts B<CA.sh> and 578B<CA.pl> help a little but not very much. 579 580Any fields in a request that are not present in a policy are silently 581deleted. This does not happen if the B<-preserveDN> option is used. To 582enforce the absence of the EMAIL field within the DN, as suggested by 583RFCs, regardless the contents of the request' subject the B<-noemailDN> 584option can be used. The behaviour should be more friendly and 585configurable. 586 587Cancelling some commands by refusing to certify a certificate can 588create an empty file. 589 590=head1 WARNINGS 591 592The B<ca> command is quirky and at times downright unfriendly. 593 594The B<ca> utility was originally meant as an example of how to do things 595in a CA. It was not supposed to be used as a full blown CA itself: 596nevertheless some people are using it for this purpose. 597 598The B<ca> command is effectively a single user command: no locking is 599done on the various files and attempts to run more than one B<ca> command 600on the same database can have unpredictable results. 601 602The B<copy_extensions> option should be used with caution. If care is 603not taken then it can be a security risk. For example if a certificate 604request contains a basicConstraints extension with CA:TRUE and the 605B<copy_extensions> value is set to B<copyall> and the user does not spot 606this when the certificate is displayed then this will hand the requestor 607a valid CA certificate. 608 609This situation can be avoided by setting B<copy_extensions> to B<copy> 610and including basicConstraints with CA:FALSE in the configuration file. 611Then if the request contains a basicConstraints extension it will be 612ignored. 613 614It is advisable to also include values for other extensions such 615as B<keyUsage> to prevent a request supplying its own values. 616 617Additional restrictions can be placed on the CA certificate itself. 618For example if the CA certificate has: 619 620 basicConstraints = CA:TRUE, pathlen:0 621 622then even if a certificate is issued with CA:TRUE it will not be valid. 623 624=head1 SEE ALSO 625 626L<req(1)|req(1)>, L<spkac(1)|spkac(1)>, L<x509(1)|x509(1)>, L<CA.pl(1)|CA.pl(1)>, 627L<config(5)|config(5)> 628 629=cut 630