6 ca - sample minimal CA application
20 [B<-crl_reason reason>]
21 [B<-crl_hold instruction>]
22 [B<-crl_compromise time>]
23 [B<-crl_CA_compromise time>]
49 [B<-extensions section>]
62 The B<ca> command is a minimal CA application. It can be used
63 to sign certificate requests in a variety of forms and generate
64 CRLs it also maintains a text database of issued certificates
67 The options descriptions will be divided into each purpose.
75 Print out a usage message.
79 This prints extra details about the operations being performed.
81 =item B<-config filename>
83 Specifies the configuration file to use.
84 Optional; for a description of the default value,
85 see L<openssl(1)/COMMAND SUMMARY>.
87 =item B<-name section>
89 Specifies the configuration file section to use (overrides
90 B<default_ca> in the B<ca> section).
94 An input filename containing a single certificate request to be
97 =item B<-ss_cert filename>
99 A single self-signed certificate to be signed by the CA.
101 =item B<-spkac filename>
103 A file containing a single Netscape signed public key and challenge
104 and additional field values to be signed by the CA. See the B<SPKAC FORMAT>
105 section for information on the required input and output format.
109 If present this should be the last option, all subsequent arguments
110 are taken as the names of files containing certificate requests.
112 =item B<-out filename>
114 The output file to output certificates to. The default is standard
115 output. The certificate details will also be printed out to this
116 file in PEM format (except that B<-spkac> outputs DER format).
118 =item B<-outdir directory>
120 The directory to output certificates to. The certificate will be
121 written to a filename consisting of the serial number in hex with
126 The CA certificate file.
128 =item B<-keyfile filename>
130 The private key to sign requests with.
132 =item B<-keyform PEM|DER>
134 The format of the data in the private key file.
137 =item B<-key password>
139 The password used to encrypt the private key. Since on some
140 systems the command line arguments are visible (e.g. Unix with
141 the 'ps' utility) this option should be used with caution.
145 Indicates the issued certificates are to be signed with the key
146 the certificate requests were signed with (given with B<-keyfile>).
147 Certificate requests signed with a different key are ignored. If
148 B<-spkac>, B<-ss_cert> or B<-gencrl> are given, B<-selfsign> is
151 A consequence of using B<-selfsign> is that the self-signed
152 certificate appears among the entries in the certificate database
153 (see the configuration option B<database>), and uses the same
154 serial number counter as all other certificates sign with the
155 self-signed certificate.
159 The key password source. For more information about the format of B<arg>
160 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
164 Don't output the text form of a certificate to the output file.
166 =item B<-startdate date>
168 This allows the start date to be explicitly set. The format of the
169 date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure), or
170 YYYYMMDDHHMMSSZ (the same as an ASN1 GeneralizedTime structure). In
171 both formats, seconds SS and timezone Z must be present.
173 =item B<-enddate date>
175 This allows the expiry date to be explicitly set. The format of the
176 date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure), or
177 YYYYMMDDHHMMSSZ (the same as an ASN1 GeneralizedTime structure). In
178 both formats, seconds SS and timezone Z must be present.
182 The number of days to certify the certificate for.
186 The message digest to use.
187 Any digest supported by the OpenSSL B<dgst> command can be used. For signing
188 algorithms that do not support a digest (i.e. Ed25519 and Ed448) any message
189 digest that is set is ignored. This option also applies to CRLs.
193 This option defines the CA "policy" to use. This is a section in
194 the configuration file which decides which fields should be mandatory
195 or match the CA certificate. Check out the B<POLICY FORMAT> section
196 for more information.
200 This is a deprecated option to make B<ca> work with very old versions of
201 the IE certificate enrollment control "certenr3". It used UniversalStrings
202 for almost everything. Since the old control has various security bugs
203 its use is strongly discouraged.
207 Normally the DN order of a certificate is the same as the order of the
208 fields in the relevant policy section. When this option is set the order
209 is the same as the request. This is largely for compatibility with the
210 older IE enrollment control which would only accept certificates if their
211 DNs match the order of the request. This is not needed for Xenroll.
215 The DN of a certificate can contain the EMAIL field if present in the
216 request DN, however it is good policy just having the e-mail set into
217 the altName extension of the certificate. When this option is set the
218 EMAIL field is removed from the certificate' subject and set only in
219 the, eventually present, extensions. The B<email_in_dn> keyword can be
220 used in the configuration file to enable this behaviour.
224 This sets the batch mode. In this mode no questions will be asked
225 and all certificates will be certified automatically.
227 =item B<-extensions section>
229 The section of the configuration file containing certificate extensions
230 to be added when a certificate is issued (defaults to B<x509_extensions>
231 unless the B<-extfile> option is used). If no extension section is
232 present then, a V1 certificate is created. If the extension section
233 is present (even if it is empty), then a V3 certificate is created. See the
234 L<x509v3_config(5)> manual page for details of the
235 extension section format.
237 =item B<-extfile file>
239 An additional configuration file to read certificate extensions from
240 (using the default section unless the B<-extensions> option is also
245 Specifying an engine (by its unique B<id> string) will cause B<ca>
246 to attempt to obtain a functional reference to the specified engine,
247 thus initialising it if needed. The engine will then be set as the default
248 for all available algorithms.
252 Supersedes subject name given in the request.
253 The arg must be formatted as I</type0=value0/type1=value1/type2=...>.
254 Keyword characters may be escaped by \ (backslash), and whitespace is retained.
255 Empty values are permitted, but the corresponding type will not be included
256 in the resulting certificate.
260 This option causes field values to be interpreted as UTF8 strings, by
261 default they are interpreted as ASCII. This means that the field
262 values, whether prompted from a terminal or obtained from a
263 configuration file, must be valid UTF8 strings.
265 =item B<-create_serial>
267 If reading serial from the text file as specified in the configuration
268 fails, specifying this option creates a new random serial to be used as next
270 To get random serial numbers, use the B<-rand_serial> flag instead; this
271 should only be used for simple error-recovery.
273 =item B<-rand_serial>
275 Generate a large random number to use as the serial number.
276 This overrides any option or configuration to use a serial number file.
278 =item B<-multivalue-rdn>
280 This option causes the -subj argument to be interpreted with full
281 support for multivalued RDNs. Example:
283 I</DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe>
285 If -multi-rdn is not used then the UID value is I<123456+CN=John Doe>.
287 =item B<-rand file...>
289 A file or files containing random data used to seed the random number
291 Multiple files can be specified separated by an OS-dependent character.
292 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
295 =item [B<-writerand file>]
297 Writes random data to the specified I<file> upon exit.
298 This can be used with a subsequent B<-rand> flag.
308 This option generates a CRL based on information in the index file.
310 =item B<-crldays num>
312 The number of days before the next CRL is due. That is the days from
313 now to place in the CRL nextUpdate field.
315 =item B<-crlhours num>
317 The number of hours before the next CRL is due.
319 =item B<-revoke filename>
321 A filename containing a certificate to revoke.
323 =item B<-valid filename>
325 A filename containing a certificate to add a Valid certificate entry.
327 =item B<-status serial>
329 Displays the revocation status of the certificate with the specified
330 serial number and exits.
334 Updates the database index to purge expired certificates.
336 =item B<-crl_reason reason>
338 Revocation reason, where B<reason> is one of: B<unspecified>, B<keyCompromise>,
339 B<CACompromise>, B<affiliationChanged>, B<superseded>, B<cessationOfOperation>,
340 B<certificateHold> or B<removeFromCRL>. The matching of B<reason> is case
341 insensitive. Setting any revocation reason will make the CRL v2.
343 In practice B<removeFromCRL> is not particularly useful because it is only used
344 in delta CRLs which are not currently implemented.
346 =item B<-crl_hold instruction>
348 This sets the CRL revocation reason code to B<certificateHold> and the hold
349 instruction to B<instruction> which must be an OID. Although any OID can be
350 used only B<holdInstructionNone> (the use of which is discouraged by RFC2459)
351 B<holdInstructionCallIssuer> or B<holdInstructionReject> will normally be used.
353 =item B<-crl_compromise time>
355 This sets the revocation reason to B<keyCompromise> and the compromise time to
356 B<time>. B<time> should be in GeneralizedTime format that is B<YYYYMMDDHHMMSSZ>.
358 =item B<-crl_CA_compromise time>
360 This is the same as B<crl_compromise> except the revocation reason is set to
363 =item B<-crlexts section>
365 The section of the configuration file containing CRL extensions to
366 include. If no CRL extension section is present then a V1 CRL is
367 created, if the CRL extension section is present (even if it is
368 empty) then a V2 CRL is created. The CRL extensions specified are
369 CRL extensions and B<not> CRL entry extensions. It should be noted
370 that some software (for example Netscape) can't handle V2 CRLs. See
371 L<x509v3_config(5)> manual page for details of the
372 extension section format.
376 =head1 CONFIGURATION FILE OPTIONS
378 The section of the configuration file containing options for B<ca>
379 is found as follows: If the B<-name> command line option is used,
380 then it names the section to be used. Otherwise the section to
381 be used must be named in the B<default_ca> option of the B<ca> section
382 of the configuration file (or in the default section of the
383 configuration file). Besides B<default_ca>, the following options are
384 read directly from the B<ca> section:
388 With the exception of B<RANDFILE>, this is probably a bug and may
389 change in future releases.
391 Many of the configuration file options are identical to command line
392 options. Where the option is present in the configuration file
393 and the command line the command line value is used. Where an
394 option is described as mandatory then it must be present in
395 the configuration file or the command line equivalent (if
402 This specifies a file containing additional B<OBJECT IDENTIFIERS>.
403 Each line of the file should consist of the numerical form of the
404 object identifier followed by white space then the short name followed
405 by white space and finally the long name.
409 This specifies a section in the configuration file containing extra
410 object identifiers. Each line should consist of the short name of the
411 object identifier followed by B<=> and the numerical form. The short
412 and long names are the same when this option is used.
414 =item B<new_certs_dir>
416 The same as the B<-outdir> command line option. It specifies
417 the directory where new certificates will be placed. Mandatory.
421 The same as B<-cert>. It gives the file containing the CA
422 certificate. Mandatory.
426 Same as the B<-keyfile> option. The file containing the
427 CA private key. Mandatory.
431 At startup the specified file is loaded into the random number generator,
432 and at exit 256 bytes will be written to it.
434 =item B<default_days>
436 The same as the B<-days> option. The number of days to certify
439 =item B<default_startdate>
441 The same as the B<-startdate> option. The start date to certify
442 a certificate for. If not set the current time is used.
444 =item B<default_enddate>
446 The same as the B<-enddate> option. Either this option or
447 B<default_days> (or the command line equivalents) must be
450 =item B<default_crl_hours default_crl_days>
452 The same as the B<-crlhours> and the B<-crldays> options. These
453 will only be used if neither command line option is present. At
454 least one of these must be present to generate a CRL.
458 The same as the B<-md> option. Mandatory except where the signing algorithm does
459 not require a digest (i.e. Ed25519 and Ed448).
463 The text database file to use. Mandatory. This file must be present
464 though initially it will be empty.
466 =item B<unique_subject>
468 If the value B<yes> is given, the valid certificate entries in the
469 database must have unique subjects. if the value B<no> is given,
470 several valid certificate entries may have the exact same subject.
471 The default value is B<yes>, to be compatible with older (pre 0.9.8)
472 versions of OpenSSL. However, to make CA certificate roll-over easier,
473 it's recommended to use the value B<no>, especially if combined with
474 the B<-selfsign> command line option.
476 Note that it is valid in some circumstances for certificates to be created
477 without any subject. In the case where there are multiple certificates without
478 subjects this does not count as a duplicate.
482 A text file containing the next serial number to use in hex. Mandatory.
483 This file must be present and contain a valid serial number.
487 A text file containing the next CRL number to use in hex. The crl number
488 will be inserted in the CRLs only if this file exists. If this file is
489 present, it must contain a valid CRL number.
491 =item B<x509_extensions>
493 The same as B<-extensions>.
495 =item B<crl_extensions>
497 The same as B<-crlexts>.
501 The same as B<-preserveDN>
505 The same as B<-noemailDN>. If you want the EMAIL field to be removed
506 from the DN of the certificate simply set this to 'no'. If not present
507 the default is to allow for the EMAIL filed in the certificate's DN.
511 The same as B<-msie_hack>
515 The same as B<-policy>. Mandatory. See the B<POLICY FORMAT> section
516 for more information.
518 =item B<name_opt>, B<cert_opt>
520 These options allow the format used to display the certificate details
521 when asking the user to confirm signing. All the options supported by
522 the B<x509> utilities B<-nameopt> and B<-certopt> switches can be used
523 here, except the B<no_signame> and B<no_sigdump> are permanently set
524 and cannot be disabled (this is because the certificate signature cannot
525 be displayed because the certificate has not been signed at this point).
527 For convenience the values B<ca_default> are accepted by both to produce
530 If neither option is present the format used in earlier versions of
531 OpenSSL is used. Use of the old format is B<strongly> discouraged because
532 it only displays fields mentioned in the B<policy> section, mishandles
533 multicharacter string types and does not display extensions.
535 =item B<copy_extensions>
537 Determines how extensions in certificate requests should be handled.
538 If set to B<none> or this option is not present then extensions are
539 ignored and not copied to the certificate. If set to B<copy> then any
540 extensions present in the request that are not already present are copied
541 to the certificate. If set to B<copyall> then all extensions in the
542 request are copied to the certificate: if the extension is already present
543 in the certificate it is deleted first. See the B<WARNINGS> section before
546 The main use of this option is to allow a certificate request to supply
547 values for certain extensions such as subjectAltName.
553 The policy section consists of a set of variables corresponding to
554 certificate DN fields. If the value is "match" then the field value
555 must match the same field in the CA certificate. If the value is
556 "supplied" then it must be present. If the value is "optional" then
557 it may be present. Any fields not mentioned in the policy section
558 are silently deleted, unless the B<-preserveDN> option is set but
559 this can be regarded more of a quirk than intended behaviour.
563 The input to the B<-spkac> command line option is a Netscape
564 signed public key and challenge. This will usually come from
565 the B<KEYGEN> tag in an HTML form to create a new private key.
566 It is however possible to create SPKACs using the B<spkac> utility.
568 The file should contain the variable SPKAC set to the value of
569 the SPKAC and also the required DN components as name value pairs.
570 If you need to include the same component twice then it can be
571 preceded by a number and a '.'.
573 When processing SPKAC format, the output is DER if the B<-out>
574 flag is used, but PEM format if sending to stdout or the B<-outdir>
579 Note: these examples assume that the B<ca> directory structure is
580 already set up and the relevant files already exist. This usually
581 involves creating a CA certificate and private key with B<req>, a
582 serial number file and an empty index file and placing them in
583 the relevant directories.
585 To use the sample configuration file below the directories demoCA,
586 demoCA/private and demoCA/newcerts would be created. The CA
587 certificate would be copied to demoCA/cacert.pem and its private
588 key to demoCA/private/cakey.pem. A file demoCA/serial would be
589 created containing for example "01" and the empty index file
593 Sign a certificate request:
595 openssl ca -in req.pem -out newcert.pem
597 Sign a certificate request, using CA extensions:
599 openssl ca -in req.pem -extensions v3_ca -out newcert.pem
603 openssl ca -gencrl -out crl.pem
605 Sign several requests:
607 openssl ca -infiles req1.pem req2.pem req3.pem
609 Certify a Netscape SPKAC:
611 openssl ca -spkac spkac.txt
613 A sample SPKAC file (the SPKAC line has been truncated for clarity):
615 SPKAC=MIG0MGAwXDANBgkqhkiG9w0BAQEFAANLADBIAkEAn7PDhCeV/xIxUg8V70YRxK2A5
617 emailAddress=steve@openssl.org
621 A sample configuration file with the relevant sections for B<ca>:
624 default_ca = CA_default # The default ca section
628 dir = ./demoCA # top dir
629 database = $dir/index.txt # index file.
630 new_certs_dir = $dir/newcerts # new certs dir
632 certificate = $dir/cacert.pem # The CA cert
633 serial = $dir/serial # serial no file
634 #rand_serial = yes # for random serial#'s
635 private_key = $dir/private/cakey.pem# CA private key
636 RANDFILE = $dir/private/.rand # random number file
638 default_days = 365 # how long to certify for
639 default_crl_days= 30 # how long before next CRL
640 default_md = md5 # md to use
642 policy = policy_any # default policy
643 email_in_dn = no # Don't add the email into cert DN
645 name_opt = ca_default # Subject name display option
646 cert_opt = ca_default # Certificate display option
647 copy_extensions = none # Don't copy extensions from request
650 countryName = supplied
651 stateOrProvinceName = optional
652 organizationName = optional
653 organizationalUnitName = optional
654 commonName = supplied
655 emailAddress = optional
659 Note: the location of all files can change either by compile time options,
660 configuration file entries, environment variables or command line options.
661 The values below reflect the default values.
663 /usr/local/ssl/lib/openssl.cnf - master configuration file
664 ./demoCA - main CA directory
665 ./demoCA/cacert.pem - CA certificate
666 ./demoCA/private/cakey.pem - CA private key
667 ./demoCA/serial - CA serial number file
668 ./demoCA/serial.old - CA serial number backup file
669 ./demoCA/index.txt - CA text database file
670 ./demoCA/index.txt.old - CA text database backup file
671 ./demoCA/certs - certificate output file
672 ./demoCA/.rnd - CA random seed information
676 The text database index file is a critical part of the process and
677 if corrupted it can be difficult to fix. It is theoretically possible
678 to rebuild the index file from all the issued certificates and a current
679 CRL: however there is no option to do this.
681 V2 CRL features like delta CRLs are not currently supported.
683 Although several requests can be input and handled at once it is only
684 possible to include one SPKAC or self-signed certificate.
688 The use of an in-memory text database can cause problems when large
689 numbers of certificates are present because, as the name implies
690 the database has to be kept in memory.
692 The B<ca> command really needs rewriting or the required functionality
693 exposed at either a command or interface level so a more friendly utility
694 (perl script or GUI) can handle things properly. The script
695 B<CA.pl> helps a little but not very much.
697 Any fields in a request that are not present in a policy are silently
698 deleted. This does not happen if the B<-preserveDN> option is used. To
699 enforce the absence of the EMAIL field within the DN, as suggested by
700 RFCs, regardless the contents of the request' subject the B<-noemailDN>
701 option can be used. The behaviour should be more friendly and
704 Canceling some commands by refusing to certify a certificate can
705 create an empty file.
709 The B<ca> command is quirky and at times downright unfriendly.
711 The B<ca> utility was originally meant as an example of how to do things
712 in a CA. It was not supposed to be used as a full blown CA itself:
713 nevertheless some people are using it for this purpose.
715 The B<ca> command is effectively a single user command: no locking is
716 done on the various files and attempts to run more than one B<ca> command
717 on the same database can have unpredictable results.
719 The B<copy_extensions> option should be used with caution. If care is
720 not taken then it can be a security risk. For example if a certificate
721 request contains a basicConstraints extension with CA:TRUE and the
722 B<copy_extensions> value is set to B<copyall> and the user does not spot
723 this when the certificate is displayed then this will hand the requester
724 a valid CA certificate.
726 This situation can be avoided by setting B<copy_extensions> to B<copy>
727 and including basicConstraints with CA:FALSE in the configuration file.
728 Then if the request contains a basicConstraints extension it will be
731 It is advisable to also include values for other extensions such
732 as B<keyUsage> to prevent a request supplying its own values.
734 Additional restrictions can be placed on the CA certificate itself.
735 For example if the CA certificate has:
737 basicConstraints = CA:TRUE, pathlen:0
739 then even if a certificate is issued with CA:TRUE it will not be valid.
743 Since OpenSSL 1.1.1, the program follows RFC5280. Specifically,
744 certificate validity period (specified by any of B<-startdate>,
745 B<-enddate> and B<-days>) will be encoded as UTCTime if the dates are
746 earlier than year 2049 (included), and as GeneralizedTime if the dates
747 are in year 2050 or later.
751 L<req(1)>, L<spkac(1)>, L<x509(1)>, L<CA.pl(1)>,
752 L<config(5)>, L<x509v3_config(5)>
756 Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
758 Licensed under the OpenSSL license (the "License"). You may not use
759 this file except in compliance with the License. You can obtain a copy
760 in the file LICENSE in the source distribution or at
761 L<https://www.openssl.org/source/license.html>.