6 ca - sample minimal CA application
16 [B<-crl_reason reason>]
17 [B<-crl_hold instruction>]
18 [B<-crl_compromise time>]
19 [B<-crl_CA_compromise time>]
44 [B<-extensions section>]
53 The B<ca> command is a minimal CA application. It can be used
54 to sign certificate requests in a variety of forms and generate
55 CRLs it also maintains a text database of issued certificates
58 The options descriptions will be divided into each purpose.
64 =item B<-config filename>
66 specifies the configuration file to use.
68 =item B<-name section>
70 specifies the configuration file section to use (overrides
71 B<default_ca> in the B<ca> section).
75 an input filename containing a single certificate request to be
78 =item B<-ss_cert filename>
80 a single self signed certificate to be signed by the CA.
82 =item B<-spkac filename>
84 a file containing a single Netscape signed public key and challenge
85 and additional field values to be signed by the CA. See the B<SPKAC FORMAT>
86 section for information on the required format.
90 if present this should be the last option, all subsequent arguments
91 are assumed to the the names of files containing certificate requests.
93 =item B<-out filename>
95 the output file to output certificates to. The default is standard
96 output. The certificate details will also be printed out to this
99 =item B<-outdir directory>
101 the directory to output certificates to. The certificate will be
102 written to a filename consisting of the serial number in hex with
107 the CA certificate file.
109 =item B<-keyfile filename>
111 the private key to sign requests with.
113 =item B<-key password>
115 the password used to encrypt the private key. Since on some
116 systems the command line arguments are visible (e.g. Unix with
117 the 'ps' utility) this option should be used with caution.
121 indicates the issued certificates are to be signed with the key
122 the certificate requests were signed with (given with B<-keyfile>).
123 Cerificate requests signed with a different key are ignored. If
124 B<-spkac>, B<-ss_cert> or B<-gencrl> are given, B<-selfsign> is
127 A consequence of using B<-selfsign> is that the self-signed
128 certificate appears among the entries in the certificate database
129 (see the configuration option B<database>), and uses the same
130 serial number counter as all other certificates sign with the
131 self-signed certificate.
135 the key password source. For more information about the format of B<arg>
136 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
140 this prints extra details about the operations being performed.
144 don't output the text form of a certificate to the output file.
146 =item B<-startdate date>
148 this allows the start date to be explicitly set. The format of the
149 date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure).
151 =item B<-enddate date>
153 this allows the expiry date to be explicitly set. The format of the
154 date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure).
158 the number of days to certify the certificate for.
162 the message digest to use. Possible values include md5, sha1 and mdc2.
163 This option also applies to CRLs.
167 this option defines the CA "policy" to use. This is a section in
168 the configuration file which decides which fields should be mandatory
169 or match the CA certificate. Check out the B<POLICY FORMAT> section
170 for more information.
174 this is a legacy option to make B<ca> work with very old versions of
175 the IE certificate enrollment control "certenr3". It used UniversalStrings
176 for almost everything. Since the old control has various security bugs
177 its use is strongly discouraged. The newer control "Xenroll" does not
182 Normally the DN order of a certificate is the same as the order of the
183 fields in the relevant policy section. When this option is set the order
184 is the same as the request. This is largely for compatibility with the
185 older IE enrollment control which would only accept certificates if their
186 DNs match the order of the request. This is not needed for Xenroll.
190 The DN of a certificate can contain the EMAIL field if present in the
191 request DN, however it is good policy just having the e-mail set into
192 the altName extension of the certificate. When this option is set the
193 EMAIL field is removed from the certificate' subject and set only in
194 the, eventually present, extensions. The B<email_in_dn> keyword can be
195 used in the configuration file to enable this behaviour.
199 this sets the batch mode. In this mode no questions will be asked
200 and all certificates will be certified automatically.
202 =item B<-extensions section>
204 the section of the configuration file containing certificate extensions
205 to be added when a certificate is issued (defaults to B<x509_extensions>
206 unless the B<-extfile> option is used). If no extension section is
207 present then, a V1 certificate is created. If the extension section
208 is present (even if it is empty), then a V3 certificate is created. See the:w
209 L<x509v3_config(5)|x509v3_config(5)> manual page for details of the
210 extension section format.
212 =item B<-extfile file>
214 an additional configuration file to read certificate extensions from
215 (using the default section unless the B<-extensions> option is also
220 specifying an engine (by its unique B<id> string) will cause B<ca>
221 to attempt to obtain a functional reference to the specified engine,
222 thus initialising it if needed. The engine will then be set as the default
223 for all available algorithms.
227 supersedes subject name given in the request.
228 The arg must be formatted as I</type0=value0/type1=value1/type2=...>,
229 characters may be escaped by \ (backslash), no spaces are skipped.
233 this option causes field values to be interpreted as UTF8 strings, by
234 default they are interpreted as ASCII. This means that the field
235 values, whether prompted from a terminal or obtained from a
236 configuration file, must be valid UTF8 strings.
238 =item B<-multivalue-rdn>
240 this option causes the -subj argument to be interpretedt with full
241 support for multivalued RDNs. Example:
243 I</DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe>
245 If -multi-rdn is not used then the UID value is I<123456+CN=John Doe>.
255 this option generates a CRL based on information in the index file.
257 =item B<-crldays num>
259 the number of days before the next CRL is due. That is the days from
260 now to place in the CRL nextUpdate field.
262 =item B<-crlhours num>
264 the number of hours before the next CRL is due.
266 =item B<-revoke filename>
268 a filename containing a certificate to revoke.
270 =item B<-crl_reason reason>
272 revocation reason, where B<reason> is one of: B<unspecified>, B<keyCompromise>,
273 B<CACompromise>, B<affiliationChanged>, B<superseded>, B<cessationOfOperation>,
274 B<certificateHold> or B<removeFromCRL>. The matching of B<reason> is case
275 insensitive. Setting any revocation reason will make the CRL v2.
277 In practive B<removeFromCRL> is not particularly useful because it is only used
278 in delta CRLs which are not currently implemented.
280 =item B<-crl_hold instruction>
282 This sets the CRL revocation reason code to B<certificateHold> and the hold
283 instruction to B<instruction> which must be an OID. Although any OID can be
284 used only B<holdInstructionNone> (the use of which is discouraged by RFC2459)
285 B<holdInstructionCallIssuer> or B<holdInstructionReject> will normally be used.
287 =item B<-crl_compromise time>
289 This sets the revocation reason to B<keyCompromise> and the compromise time to
290 B<time>. B<time> should be in GeneralizedTime format that is B<YYYYMMDDHHMMSSZ>.
292 =item B<-crl_CA_compromise time>
294 This is the same as B<crl_compromise> except the revocation reason is set to
297 =item B<-crlexts section>
299 the section of the configuration file containing CRL extensions to
300 include. If no CRL extension section is present then a V1 CRL is
301 created, if the CRL extension section is present (even if it is
302 empty) then a V2 CRL is created. The CRL extensions specified are
303 CRL extensions and B<not> CRL entry extensions. It should be noted
304 that some software (for example Netscape) can't handle V2 CRLs. See
305 L<x509v3_config(5)|x509v3_config(5)> manual page for details of the
306 extension section format.
310 =head1 CONFIGURATION FILE OPTIONS
312 The section of the configuration file containing options for B<ca>
313 is found as follows: If the B<-name> command line option is used,
314 then it names the section to be used. Otherwise the section to
315 be used must be named in the B<default_ca> option of the B<ca> section
316 of the configuration file (or in the default section of the
317 configuration file). Besides B<default_ca>, the following options are
318 read directly from the B<ca> section:
322 With the exception of B<RANDFILE>, this is probably a bug and may
323 change in future releases.
325 Many of the configuration file options are identical to command line
326 options. Where the option is present in the configuration file
327 and the command line the command line value is used. Where an
328 option is described as mandatory then it must be present in
329 the configuration file or the command line equivalent (if
336 This specifies a file containing additional B<OBJECT IDENTIFIERS>.
337 Each line of the file should consist of the numerical form of the
338 object identifier followed by white space then the short name followed
339 by white space and finally the long name.
343 This specifies a section in the configuration file containing extra
344 object identifiers. Each line should consist of the short name of the
345 object identifier followed by B<=> and the numerical form. The short
346 and long names are the same when this option is used.
348 =item B<new_certs_dir>
350 the same as the B<-outdir> command line option. It specifies
351 the directory where new certificates will be placed. Mandatory.
355 the same as B<-cert>. It gives the file containing the CA
356 certificate. Mandatory.
360 same as the B<-keyfile> option. The file containing the
361 CA private key. Mandatory.
365 a file used to read and write random number seed information, or
366 an EGD socket (see L<RAND_egd(3)|RAND_egd(3)>).
368 =item B<default_days>
370 the same as the B<-days> option. The number of days to certify
373 =item B<default_startdate>
375 the same as the B<-startdate> option. The start date to certify
376 a certificate for. If not set the current time is used.
378 =item B<default_enddate>
380 the same as the B<-enddate> option. Either this option or
381 B<default_days> (or the command line equivalents) must be
384 =item B<default_crl_hours default_crl_days>
386 the same as the B<-crlhours> and the B<-crldays> options. These
387 will only be used if neither command line option is present. At
388 least one of these must be present to generate a CRL.
392 the same as the B<-md> option. The message digest to use. Mandatory.
396 the text database file to use. Mandatory. This file must be present
397 though initially it will be empty.
399 =item B<unique_subject>
401 if the value B<yes> is given, the valid certificate entries in the
402 database must have unique subjects. if the value B<no> is given,
403 several valid certificate entries may have the exact same subject.
404 The default value is B<yes>, to be compatible with older (pre 0.9.8)
405 versions of OpenSSL. However, to make CA certificate roll-over easier,
406 it's recommended to use the value B<no>, especially if combined with
407 the B<-selfsign> command line option.
411 a text file containing the next serial number to use in hex. Mandatory.
412 This file must be present and contain a valid serial number.
416 a text file containing the next CRL number to use in hex. The crl number
417 will be inserted in the CRLs only if this file exists. If this file is
418 present, it must contain a valid CRL number.
420 =item B<x509_extensions>
422 the same as B<-extensions>.
424 =item B<crl_extensions>
426 the same as B<-crlexts>.
430 the same as B<-preserveDN>
434 the same as B<-noemailDN>. If you want the EMAIL field to be removed
435 from the DN of the certificate simply set this to 'no'. If not present
436 the default is to allow for the EMAIL filed in the certificate's DN.
440 the same as B<-msie_hack>
444 the same as B<-policy>. Mandatory. See the B<POLICY FORMAT> section
445 for more information.
447 =item B<name_opt>, B<cert_opt>
449 these options allow the format used to display the certificate details
450 when asking the user to confirm signing. All the options supported by
451 the B<x509> utilities B<-nameopt> and B<-certopt> switches can be used
452 here, except the B<no_signame> and B<no_sigdump> are permanently set
453 and cannot be disabled (this is because the certificate signature cannot
454 be displayed because the certificate has not been signed at this point).
456 For convenience the values B<ca_default> are accepted by both to produce
459 If neither option is present the format used in earlier versions of
460 OpenSSL is used. Use of the old format is B<strongly> discouraged because
461 it only displays fields mentioned in the B<policy> section, mishandles
462 multicharacter string types and does not display extensions.
464 =item B<copy_extensions>
466 determines how extensions in certificate requests should be handled.
467 If set to B<none> or this option is not present then extensions are
468 ignored and not copied to the certificate. If set to B<copy> then any
469 extensions present in the request that are not already present are copied
470 to the certificate. If set to B<copyall> then all extensions in the
471 request are copied to the certificate: if the extension is already present
472 in the certificate it is deleted first. See the B<WARNINGS> section before
475 The main use of this option is to allow a certificate request to supply
476 values for certain extensions such as subjectAltName.
482 The policy section consists of a set of variables corresponding to
483 certificate DN fields. If the value is "match" then the field value
484 must match the same field in the CA certificate. If the value is
485 "supplied" then it must be present. If the value is "optional" then
486 it may be present. Any fields not mentioned in the policy section
487 are silently deleted, unless the B<-preserveDN> option is set but
488 this can be regarded more of a quirk than intended behaviour.
492 The input to the B<-spkac> command line option is a Netscape
493 signed public key and challenge. This will usually come from
494 the B<KEYGEN> tag in an HTML form to create a new private key.
495 It is however possible to create SPKACs using the B<spkac> utility.
497 The file should contain the variable SPKAC set to the value of
498 the SPKAC and also the required DN components as name value pairs.
499 If you need to include the same component twice then it can be
500 preceded by a number and a '.'.
504 Note: these examples assume that the B<ca> directory structure is
505 already set up and the relevant files already exist. This usually
506 involves creating a CA certificate and private key with B<req>, a
507 serial number file and an empty index file and placing them in
508 the relevant directories.
510 To use the sample configuration file below the directories demoCA,
511 demoCA/private and demoCA/newcerts would be created. The CA
512 certificate would be copied to demoCA/cacert.pem and its private
513 key to demoCA/private/cakey.pem. A file demoCA/serial would be
514 created containing for example "01" and the empty index file
518 Sign a certificate request:
520 openssl ca -in req.pem -out newcert.pem
522 Sign a certificate request, using CA extensions:
524 openssl ca -in req.pem -extensions v3_ca -out newcert.pem
528 openssl ca -gencrl -out crl.pem
530 Sign several requests:
532 openssl ca -infiles req1.pem req2.pem req3.pem
534 Certify a Netscape SPKAC:
536 openssl ca -spkac spkac.txt
538 A sample SPKAC file (the SPKAC line has been truncated for clarity):
540 SPKAC=MIG0MGAwXDANBgkqhkiG9w0BAQEFAANLADBIAkEAn7PDhCeV/xIxUg8V70YRxK2A5
542 emailAddress=steve@openssl.org
546 A sample configuration file with the relevant sections for B<ca>:
549 default_ca = CA_default # The default ca section
553 dir = ./demoCA # top dir
554 database = $dir/index.txt # index file.
555 new_certs_dir = $dir/newcerts # new certs dir
557 certificate = $dir/cacert.pem # The CA cert
558 serial = $dir/serial # serial no file
559 private_key = $dir/private/cakey.pem# CA private key
560 RANDFILE = $dir/private/.rand # random number file
562 default_days = 365 # how long to certify for
563 default_crl_days= 30 # how long before next CRL
564 default_md = md5 # md to use
566 policy = policy_any # default policy
567 email_in_dn = no # Don't add the email into cert DN
569 name_opt = ca_default # Subject name display option
570 cert_opt = ca_default # Certificate display option
571 copy_extensions = none # Don't copy extensions from request
574 countryName = supplied
575 stateOrProvinceName = optional
576 organizationName = optional
577 organizationalUnitName = optional
578 commonName = supplied
579 emailAddress = optional
583 Note: the location of all files can change either by compile time options,
584 configuration file entries, environment variables or command line options.
585 The values below reflect the default values.
587 /usr/local/ssl/lib/openssl.cnf - master configuration file
588 ./demoCA - main CA directory
589 ./demoCA/cacert.pem - CA certificate
590 ./demoCA/private/cakey.pem - CA private key
591 ./demoCA/serial - CA serial number file
592 ./demoCA/serial.old - CA serial number backup file
593 ./demoCA/index.txt - CA text database file
594 ./demoCA/index.txt.old - CA text database backup file
595 ./demoCA/certs - certificate output file
596 ./demoCA/.rnd - CA random seed information
598 =head1 ENVIRONMENT VARIABLES
600 B<OPENSSL_CONF> reflects the location of master configuration file it can
601 be overridden by the B<-config> command line option.
605 The text database index file is a critical part of the process and
606 if corrupted it can be difficult to fix. It is theoretically possible
607 to rebuild the index file from all the issued certificates and a current
608 CRL: however there is no option to do this.
610 V2 CRL features like delta CRLs are not currently supported.
612 Although several requests can be input and handled at once it is only
613 possible to include one SPKAC or self signed certificate.
617 The use of an in memory text database can cause problems when large
618 numbers of certificates are present because, as the name implies
619 the database has to be kept in memory.
621 The B<ca> command really needs rewriting or the required functionality
622 exposed at either a command or interface level so a more friendly utility
623 (perl script or GUI) can handle things properly. The scripts B<CA.sh> and
624 B<CA.pl> help a little but not very much.
626 Any fields in a request that are not present in a policy are silently
627 deleted. This does not happen if the B<-preserveDN> option is used. To
628 enforce the absence of the EMAIL field within the DN, as suggested by
629 RFCs, regardless the contents of the request' subject the B<-noemailDN>
630 option can be used. The behaviour should be more friendly and
633 Cancelling some commands by refusing to certify a certificate can
634 create an empty file.
638 The B<ca> command is quirky and at times downright unfriendly.
640 The B<ca> utility was originally meant as an example of how to do things
641 in a CA. It was not supposed to be used as a full blown CA itself:
642 nevertheless some people are using it for this purpose.
644 The B<ca> command is effectively a single user command: no locking is
645 done on the various files and attempts to run more than one B<ca> command
646 on the same database can have unpredictable results.
648 The B<copy_extensions> option should be used with caution. If care is
649 not taken then it can be a security risk. For example if a certificate
650 request contains a basicConstraints extension with CA:TRUE and the
651 B<copy_extensions> value is set to B<copyall> and the user does not spot
652 this when the certificate is displayed then this will hand the requestor
653 a valid CA certificate.
655 This situation can be avoided by setting B<copy_extensions> to B<copy>
656 and including basicConstraints with CA:FALSE in the configuration file.
657 Then if the request contains a basicConstraints extension it will be
660 It is advisable to also include values for other extensions such
661 as B<keyUsage> to prevent a request supplying its own values.
663 Additional restrictions can be placed on the CA certificate itself.
664 For example if the CA certificate has:
666 basicConstraints = CA:TRUE, pathlen:0
668 then even if a certificate is issued with CA:TRUE it will not be valid.
672 L<req(1)|req(1)>, L<spkac(1)|spkac(1)>, L<x509(1)|x509(1)>, L<CA.pl(1)|CA.pl(1)>,
673 L<config(5)|config(5)>, L<x509v3_config(5)|x509v3_config(5)>