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>]
63 The B<ca> command is a minimal CA application. It can be used
64 to sign certificate requests in a variety of forms and generate
65 CRLs it also maintains a text database of issued certificates
68 The options descriptions will be divided into each purpose.
76 Print out a usage message.
80 This prints extra details about the operations being performed.
82 =item B<-config filename>
84 Specifies the configuration file to use.
85 Optional; for a description of the default value,
86 see L<openssl(1)/COMMAND SUMMARY>.
88 =item B<-name section>
90 Specifies the configuration file section to use (overrides
91 B<default_ca> in the B<ca> section).
95 An input filename containing a single certificate request to be
98 =item B<-ss_cert filename>
100 A single self-signed certificate to be signed by the CA.
102 =item B<-spkac filename>
104 A file containing a single Netscape signed public key and challenge
105 and additional field values to be signed by the CA. See the B<SPKAC FORMAT>
106 section for information on the required input and output format.
110 If present this should be the last option, all subsequent arguments
111 are taken as the names of files containing certificate requests.
113 =item B<-out filename>
115 The output file to output certificates to. The default is standard
116 output. The certificate details will also be printed out to this
117 file in PEM format (except that B<-spkac> outputs DER format).
119 =item B<-outdir directory>
121 The directory to output certificates to. The certificate will be
122 written to a filename consisting of the serial number in hex with
127 The CA certificate file.
129 =item B<-keyfile filename>
131 The private key to sign requests with.
133 =item B<-keyform PEM|DER>
135 The format of the data in the private key file.
138 =item B<-sigopt nm:v>
140 Pass options to the signature algorithm during sign or verify operations.
141 Names and values of these options are algorithm-specific.
143 =item B<-key password>
145 The password used to encrypt the private key. Since on some
146 systems the command line arguments are visible (e.g. Unix with
147 the 'ps' utility) this option should be used with caution.
151 Indicates the issued certificates are to be signed with the key
152 the certificate requests were signed with (given with B<-keyfile>).
153 Certificate requests signed with a different key are ignored. If
154 B<-spkac>, B<-ss_cert> or B<-gencrl> are given, B<-selfsign> is
157 A consequence of using B<-selfsign> is that the self-signed
158 certificate appears among the entries in the certificate database
159 (see the configuration option B<database>), and uses the same
160 serial number counter as all other certificates sign with the
161 self-signed certificate.
165 The key password source. For more information about the format of B<arg>
166 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
170 Don't output the text form of a certificate to the output file.
172 =item B<-startdate date>
174 This allows the start date to be explicitly set. The format of the
175 date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure), or
176 YYYYMMDDHHMMSSZ (the same as an ASN1 GeneralizedTime structure). In
177 both formats, seconds SS and timezone Z must be present.
179 =item B<-enddate date>
181 This allows the expiry date to be explicitly set. The format of the
182 date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure), or
183 YYYYMMDDHHMMSSZ (the same as an ASN1 GeneralizedTime structure). In
184 both formats, seconds SS and timezone Z must be present.
188 The number of days to certify the certificate for.
192 The message digest to use.
193 Any digest supported by the OpenSSL B<dgst> command can be used. For signing
194 algorithms that do not support a digest (i.e. Ed25519 and Ed448) any message
195 digest that is set is ignored. This option also applies to CRLs.
199 This option defines the CA "policy" to use. This is a section in
200 the configuration file which decides which fields should be mandatory
201 or match the CA certificate. Check out the B<POLICY FORMAT> section
202 for more information.
206 This is a deprecated option to make B<ca> work with very old versions of
207 the IE certificate enrollment control "certenr3". It used UniversalStrings
208 for almost everything. Since the old control has various security bugs
209 its use is strongly discouraged.
213 Normally the DN order of a certificate is the same as the order of the
214 fields in the relevant policy section. When this option is set the order
215 is the same as the request. This is largely for compatibility with the
216 older IE enrollment control which would only accept certificates if their
217 DNs match the order of the request. This is not needed for Xenroll.
221 The DN of a certificate can contain the EMAIL field if present in the
222 request DN, however, it is good policy just having the e-mail set into
223 the altName extension of the certificate. When this option is set the
224 EMAIL field is removed from the certificate' subject and set only in
225 the, eventually present, extensions. The B<email_in_dn> keyword can be
226 used in the configuration file to enable this behaviour.
230 This sets the batch mode. In this mode no questions will be asked
231 and all certificates will be certified automatically.
233 =item B<-extensions section>
235 The section of the configuration file containing certificate extensions
236 to be added when a certificate is issued (defaults to B<x509_extensions>
237 unless the B<-extfile> option is used). If no extension section is
238 present then, a V1 certificate is created. If the extension section
239 is present (even if it is empty), then a V3 certificate is created. See the
240 L<x509v3_config(5)> manual page for details of the
241 extension section format.
243 =item B<-extfile file>
245 An additional configuration file to read certificate extensions from
246 (using the default section unless the B<-extensions> option is also
251 Specifying an engine (by its unique B<id> string) will cause B<ca>
252 to attempt to obtain a functional reference to the specified engine,
253 thus initialising it if needed. The engine will then be set as the default
254 for all available algorithms.
258 Supersedes subject name given in the request.
259 The arg must be formatted as I</type0=value0/type1=value1/type2=...>.
260 Keyword characters may be escaped by \ (backslash), and whitespace is retained.
261 Empty values are permitted, but the corresponding type will not be included
262 in the resulting certificate.
266 This option causes field values to be interpreted as UTF8 strings, by
267 default they are interpreted as ASCII. This means that the field
268 values, whether prompted from a terminal or obtained from a
269 configuration file, must be valid UTF8 strings.
271 =item B<-create_serial>
273 If reading serial from the text file as specified in the configuration
274 fails, specifying this option creates a new random serial to be used as next
276 To get random serial numbers, use the B<-rand_serial> flag instead; this
277 should only be used for simple error-recovery.
279 =item B<-rand_serial>
281 Generate a large random number to use as the serial number.
282 This overrides any option or configuration to use a serial number file.
284 =item B<-multivalue-rdn>
286 This option causes the -subj argument to be interpreted with full
287 support for multivalued RDNs. Example:
289 I</DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe>
291 If -multi-rdn is not used then the UID value is I<123456+CN=John Doe>.
293 =item B<-rand file...>
295 A file or files containing random data used to seed the random number
297 Multiple files can be specified separated by an OS-dependent character.
298 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
301 =item [B<-writerand file>]
303 Writes random data to the specified I<file> upon exit.
304 This can be used with a subsequent B<-rand> flag.
314 This option generates a CRL based on information in the index file.
316 =item B<-crldays num>
318 The number of days before the next CRL is due. That is the days from
319 now to place in the CRL nextUpdate field.
321 =item B<-crlhours num>
323 The number of hours before the next CRL is due.
325 =item B<-revoke filename>
327 A filename containing a certificate to revoke.
329 =item B<-valid filename>
331 A filename containing a certificate to add a Valid certificate entry.
333 =item B<-status serial>
335 Displays the revocation status of the certificate with the specified
336 serial number and exits.
340 Updates the database index to purge expired certificates.
342 =item B<-crl_reason reason>
344 Revocation reason, where B<reason> is one of: B<unspecified>, B<keyCompromise>,
345 B<CACompromise>, B<affiliationChanged>, B<superseded>, B<cessationOfOperation>,
346 B<certificateHold> or B<removeFromCRL>. The matching of B<reason> is case
347 insensitive. Setting any revocation reason will make the CRL v2.
349 In practice B<removeFromCRL> is not particularly useful because it is only used
350 in delta CRLs which are not currently implemented.
352 =item B<-crl_hold instruction>
354 This sets the CRL revocation reason code to B<certificateHold> and the hold
355 instruction to B<instruction> which must be an OID. Although any OID can be
356 used only B<holdInstructionNone> (the use of which is discouraged by RFC2459)
357 B<holdInstructionCallIssuer> or B<holdInstructionReject> will normally be used.
359 =item B<-crl_compromise time>
361 This sets the revocation reason to B<keyCompromise> and the compromise time to
362 B<time>. B<time> should be in GeneralizedTime format that is B<YYYYMMDDHHMMSSZ>.
364 =item B<-crl_CA_compromise time>
366 This is the same as B<crl_compromise> except the revocation reason is set to
369 =item B<-crlexts section>
371 The section of the configuration file containing CRL extensions to
372 include. If no CRL extension section is present then a V1 CRL is
373 created, if the CRL extension section is present (even if it is
374 empty) then a V2 CRL is created. The CRL extensions specified are
375 CRL extensions and B<not> CRL entry extensions. It should be noted
376 that some software (for example Netscape) can't handle V2 CRLs. See
377 L<x509v3_config(5)> manual page for details of the
378 extension section format.
382 =head1 CONFIGURATION FILE OPTIONS
384 The section of the configuration file containing options for B<ca>
385 is found as follows: If the B<-name> command line option is used,
386 then it names the section to be used. Otherwise the section to
387 be used must be named in the B<default_ca> option of the B<ca> section
388 of the configuration file (or in the default section of the
389 configuration file). Besides B<default_ca>, the following options are
390 read directly from the B<ca> section:
394 With the exception of B<RANDFILE>, this is probably a bug and may
395 change in future releases.
397 Many of the configuration file options are identical to command line
398 options. Where the option is present in the configuration file
399 and the command line the command line value is used. Where an
400 option is described as mandatory then it must be present in
401 the configuration file or the command line equivalent (if
408 This specifies a file containing additional B<OBJECT IDENTIFIERS>.
409 Each line of the file should consist of the numerical form of the
410 object identifier followed by white space then the short name followed
411 by white space and finally the long name.
415 This specifies a section in the configuration file containing extra
416 object identifiers. Each line should consist of the short name of the
417 object identifier followed by B<=> and the numerical form. The short
418 and long names are the same when this option is used.
420 =item B<new_certs_dir>
422 The same as the B<-outdir> command line option. It specifies
423 the directory where new certificates will be placed. Mandatory.
427 The same as B<-cert>. It gives the file containing the CA
428 certificate. Mandatory.
432 Same as the B<-keyfile> option. The file containing the
433 CA private key. Mandatory.
437 At startup the specified file is loaded into the random number generator,
438 and at exit 256 bytes will be written to it.
440 =item B<default_days>
442 The same as the B<-days> option. The number of days to certify
445 =item B<default_startdate>
447 The same as the B<-startdate> option. The start date to certify
448 a certificate for. If not set the current time is used.
450 =item B<default_enddate>
452 The same as the B<-enddate> option. Either this option or
453 B<default_days> (or the command line equivalents) must be
456 =item B<default_crl_hours default_crl_days>
458 The same as the B<-crlhours> and the B<-crldays> options. These
459 will only be used if neither command line option is present. At
460 least one of these must be present to generate a CRL.
464 The same as the B<-md> option. Mandatory except where the signing algorithm does
465 not require a digest (i.e. Ed25519 and Ed448).
469 The text database file to use. Mandatory. This file must be present
470 though initially it will be empty.
472 =item B<unique_subject>
474 If the value B<yes> is given, the valid certificate entries in the
475 database must have unique subjects. if the value B<no> is given,
476 several valid certificate entries may have the exact same subject.
477 The default value is B<yes>, to be compatible with older (pre 0.9.8)
478 versions of OpenSSL. However, to make CA certificate roll-over easier,
479 it's recommended to use the value B<no>, especially if combined with
480 the B<-selfsign> command line option.
482 Note that it is valid in some circumstances for certificates to be created
483 without any subject. In the case where there are multiple certificates without
484 subjects this does not count as a duplicate.
488 A text file containing the next serial number to use in hex. Mandatory.
489 This file must be present and contain a valid serial number.
493 A text file containing the next CRL number to use in hex. The crl number
494 will be inserted in the CRLs only if this file exists. If this file is
495 present, it must contain a valid CRL number.
497 =item B<x509_extensions>
499 The same as B<-extensions>.
501 =item B<crl_extensions>
503 The same as B<-crlexts>.
507 The same as B<-preserveDN>
511 The same as B<-noemailDN>. If you want the EMAIL field to be removed
512 from the DN of the certificate simply set this to 'no'. If not present
513 the default is to allow for the EMAIL filed in the certificate's DN.
517 The same as B<-msie_hack>
521 The same as B<-policy>. Mandatory. See the B<POLICY FORMAT> section
522 for more information.
524 =item B<name_opt>, B<cert_opt>
526 These options allow the format used to display the certificate details
527 when asking the user to confirm signing. All the options supported by
528 the B<x509> utilities B<-nameopt> and B<-certopt> switches can be used
529 here, except the B<no_signame> and B<no_sigdump> are permanently set
530 and cannot be disabled (this is because the certificate signature cannot
531 be displayed because the certificate has not been signed at this point).
533 For convenience the values B<ca_default> are accepted by both to produce
536 If neither option is present the format used in earlier versions of
537 OpenSSL is used. Use of the old format is B<strongly> discouraged because
538 it only displays fields mentioned in the B<policy> section, mishandles
539 multicharacter string types and does not display extensions.
541 =item B<copy_extensions>
543 Determines how extensions in certificate requests should be handled.
544 If set to B<none> or this option is not present then extensions are
545 ignored and not copied to the certificate. If set to B<copy> then any
546 extensions present in the request that are not already present are copied
547 to the certificate. If set to B<copyall> then all extensions in the
548 request are copied to the certificate: if the extension is already present
549 in the certificate it is deleted first. See the B<WARNINGS> section before
552 The main use of this option is to allow a certificate request to supply
553 values for certain extensions such as subjectAltName.
559 The policy section consists of a set of variables corresponding to
560 certificate DN fields. If the value is "match" then the field value
561 must match the same field in the CA certificate. If the value is
562 "supplied" then it must be present. If the value is "optional" then
563 it may be present. Any fields not mentioned in the policy section
564 are silently deleted, unless the B<-preserveDN> option is set but
565 this can be regarded more of a quirk than intended behaviour.
569 The input to the B<-spkac> command line option is a Netscape
570 signed public key and challenge. This will usually come from
571 the B<KEYGEN> tag in an HTML form to create a new private key.
572 It is however possible to create SPKACs using the B<spkac> utility.
574 The file should contain the variable SPKAC set to the value of
575 the SPKAC and also the required DN components as name value pairs.
576 If you need to include the same component twice then it can be
577 preceded by a number and a '.'.
579 When processing SPKAC format, the output is DER if the B<-out>
580 flag is used, but PEM format if sending to stdout or the B<-outdir>
585 Note: these examples assume that the B<ca> directory structure is
586 already set up and the relevant files already exist. This usually
587 involves creating a CA certificate and private key with B<req>, a
588 serial number file and an empty index file and placing them in
589 the relevant directories.
591 To use the sample configuration file below the directories demoCA,
592 demoCA/private and demoCA/newcerts would be created. The CA
593 certificate would be copied to demoCA/cacert.pem and its private
594 key to demoCA/private/cakey.pem. A file demoCA/serial would be
595 created containing for example "01" and the empty index file
599 Sign a certificate request:
601 openssl ca -in req.pem -out newcert.pem
603 Sign a certificate request, using CA extensions:
605 openssl ca -in req.pem -extensions v3_ca -out newcert.pem
609 openssl ca -gencrl -out crl.pem
611 Sign several requests:
613 openssl ca -infiles req1.pem req2.pem req3.pem
615 Certify a Netscape SPKAC:
617 openssl ca -spkac spkac.txt
619 A sample SPKAC file (the SPKAC line has been truncated for clarity):
621 SPKAC=MIG0MGAwXDANBgkqhkiG9w0BAQEFAANLADBIAkEAn7PDhCeV/xIxUg8V70YRxK2A5
623 emailAddress=steve@openssl.org
627 A sample configuration file with the relevant sections for B<ca>:
630 default_ca = CA_default # The default ca section
634 dir = ./demoCA # top dir
635 database = $dir/index.txt # index file.
636 new_certs_dir = $dir/newcerts # new certs dir
638 certificate = $dir/cacert.pem # The CA cert
639 serial = $dir/serial # serial no file
640 #rand_serial = yes # for random serial#'s
641 private_key = $dir/private/cakey.pem# CA private key
642 RANDFILE = $dir/private/.rand # random number file
644 default_days = 365 # how long to certify for
645 default_crl_days= 30 # how long before next CRL
646 default_md = md5 # md to use
648 policy = policy_any # default policy
649 email_in_dn = no # Don't add the email into cert DN
651 name_opt = ca_default # Subject name display option
652 cert_opt = ca_default # Certificate display option
653 copy_extensions = none # Don't copy extensions from request
656 countryName = supplied
657 stateOrProvinceName = optional
658 organizationName = optional
659 organizationalUnitName = optional
660 commonName = supplied
661 emailAddress = optional
665 Note: the location of all files can change either by compile time options,
666 configuration file entries, environment variables or command line options.
667 The values below reflect the default values.
669 /usr/local/ssl/lib/openssl.cnf - master configuration file
670 ./demoCA - main CA directory
671 ./demoCA/cacert.pem - CA certificate
672 ./demoCA/private/cakey.pem - CA private key
673 ./demoCA/serial - CA serial number file
674 ./demoCA/serial.old - CA serial number backup file
675 ./demoCA/index.txt - CA text database file
676 ./demoCA/index.txt.old - CA text database backup file
677 ./demoCA/certs - certificate output file
678 ./demoCA/.rnd - CA random seed information
682 The text database index file is a critical part of the process and
683 if corrupted it can be difficult to fix. It is theoretically possible
684 to rebuild the index file from all the issued certificates and a current
685 CRL: however there is no option to do this.
687 V2 CRL features like delta CRLs are not currently supported.
689 Although several requests can be input and handled at once it is only
690 possible to include one SPKAC or self-signed certificate.
694 The use of an in-memory text database can cause problems when large
695 numbers of certificates are present because, as the name implies
696 the database has to be kept in memory.
698 The B<ca> command really needs rewriting or the required functionality
699 exposed at either a command or interface level so a more friendly utility
700 (perl script or GUI) can handle things properly. The script
701 B<CA.pl> helps a little but not very much.
703 Any fields in a request that are not present in a policy are silently
704 deleted. This does not happen if the B<-preserveDN> option is used. To
705 enforce the absence of the EMAIL field within the DN, as suggested by
706 RFCs, regardless the contents of the request' subject the B<-noemailDN>
707 option can be used. The behaviour should be more friendly and
710 Canceling some commands by refusing to certify a certificate can
711 create an empty file.
715 The B<ca> command is quirky and at times downright unfriendly.
717 The B<ca> utility was originally meant as an example of how to do things
718 in a CA. It was not supposed to be used as a full blown CA itself:
719 nevertheless some people are using it for this purpose.
721 The B<ca> command is effectively a single user command: no locking is
722 done on the various files and attempts to run more than one B<ca> command
723 on the same database can have unpredictable results.
725 The B<copy_extensions> option should be used with caution. If care is
726 not taken then it can be a security risk. For example if a certificate
727 request contains a basicConstraints extension with CA:TRUE and the
728 B<copy_extensions> value is set to B<copyall> and the user does not spot
729 this when the certificate is displayed then this will hand the requester
730 a valid CA certificate.
732 This situation can be avoided by setting B<copy_extensions> to B<copy>
733 and including basicConstraints with CA:FALSE in the configuration file.
734 Then if the request contains a basicConstraints extension it will be
737 It is advisable to also include values for other extensions such
738 as B<keyUsage> to prevent a request supplying its own values.
740 Additional restrictions can be placed on the CA certificate itself.
741 For example if the CA certificate has:
743 basicConstraints = CA:TRUE, pathlen:0
745 then even if a certificate is issued with CA:TRUE it will not be valid.
749 Since OpenSSL 1.1.1, the program follows RFC5280. Specifically,
750 certificate validity period (specified by any of B<-startdate>,
751 B<-enddate> and B<-days>) will be encoded as UTCTime if the dates are
752 earlier than year 2049 (included), and as GeneralizedTime if the dates
753 are in year 2050 or later.
757 L<req(1)>, L<spkac(1)>, L<x509(1)>, L<CA.pl(1)>,
758 L<config(5)>, L<x509v3_config(5)>
762 Copyright 2000-2020 The OpenSSL Project Authors. All Rights Reserved.
764 Licensed under the OpenSSL license (the "License"). You may not use
765 this file except in compliance with the License. You can obtain a copy
766 in the file LICENSE in the source distribution or at
767 L<https://www.openssl.org/source/license.html>.