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>]
61 [B<-sm2-hex-id hex-string>]
65 The B<ca> command is a minimal CA application. It can be used
66 to sign certificate requests in a variety of forms and generate
67 CRLs it also maintains a text database of issued certificates
70 The options descriptions will be divided into each purpose.
78 Print out a usage message.
82 This prints extra details about the operations being performed.
84 =item B<-config filename>
86 Specifies the configuration file to use.
87 Optional; for a description of the default value,
88 see L<openssl(1)/COMMAND SUMMARY>.
90 =item B<-name section>
92 Specifies the configuration file section to use (overrides
93 B<default_ca> in the B<ca> section).
97 An input filename containing a single certificate request to be
100 =item B<-ss_cert filename>
102 A single self-signed certificate to be signed by the CA.
104 =item B<-spkac filename>
106 A file containing a single Netscape signed public key and challenge
107 and additional field values to be signed by the CA. See the B<SPKAC FORMAT>
108 section for information on the required input and output format.
112 If present this should be the last option, all subsequent arguments
113 are taken as the names of files containing certificate requests.
115 =item B<-out filename>
117 The output file to output certificates to. The default is standard
118 output. The certificate details will also be printed out to this
119 file in PEM format (except that B<-spkac> outputs DER format).
121 =item B<-outdir directory>
123 The directory to output certificates to. The certificate will be
124 written to a filename consisting of the serial number in hex with
129 The CA certificate file.
131 =item B<-keyfile filename>
133 The private key to sign requests with.
135 =item B<-keyform PEM|DER>
137 The format of the data in the private key file.
140 =item B<-sigopt nm:v>
142 Pass options to the signature algorithm during sign or verify operations.
143 Names and values of these options are algorithm-specific.
145 =item B<-key password>
147 The password used to encrypt the private key. Since on some
148 systems the command line arguments are visible (e.g. Unix with
149 the 'ps' utility) this option should be used with caution.
153 Indicates the issued certificates are to be signed with the key
154 the certificate requests were signed with (given with B<-keyfile>).
155 Certificate requests signed with a different key are ignored. If
156 B<-spkac>, B<-ss_cert> or B<-gencrl> are given, B<-selfsign> is
159 A consequence of using B<-selfsign> is that the self-signed
160 certificate appears among the entries in the certificate database
161 (see the configuration option B<database>), and uses the same
162 serial number counter as all other certificates sign with the
163 self-signed certificate.
167 The key password source. For more information about the format of B<arg>
168 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
172 Don't output the text form of a certificate to the output file.
174 =item B<-startdate date>
176 This allows the start date to be explicitly set. The format of the
177 date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure), or
178 YYYYMMDDHHMMSSZ (the same as an ASN1 GeneralizedTime structure). In
179 both formats, seconds SS and timezone Z must be present.
181 =item B<-enddate date>
183 This allows the expiry date to be explicitly set. The format of the
184 date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure), or
185 YYYYMMDDHHMMSSZ (the same as an ASN1 GeneralizedTime structure). In
186 both formats, seconds SS and timezone Z must be present.
190 The number of days to certify the certificate for.
194 The message digest to use.
195 Any digest supported by the OpenSSL B<dgst> command can be used. For signing
196 algorithms that do not support a digest (i.e. Ed25519 and Ed448) any message
197 digest that is set is ignored. This option also applies to CRLs.
201 This option defines the CA "policy" to use. This is a section in
202 the configuration file which decides which fields should be mandatory
203 or match the CA certificate. Check out the B<POLICY FORMAT> section
204 for more information.
208 This is a deprecated option to make B<ca> work with very old versions of
209 the IE certificate enrollment control "certenr3". It used UniversalStrings
210 for almost everything. Since the old control has various security bugs
211 its use is strongly discouraged.
215 Normally the DN order of a certificate is the same as the order of the
216 fields in the relevant policy section. When this option is set the order
217 is the same as the request. This is largely for compatibility with the
218 older IE enrollment control which would only accept certificates if their
219 DNs match the order of the request. This is not needed for Xenroll.
223 The DN of a certificate can contain the EMAIL field if present in the
224 request DN, however it is good policy just having the e-mail set into
225 the altName extension of the certificate. When this option is set the
226 EMAIL field is removed from the certificate' subject and set only in
227 the, eventually present, extensions. The B<email_in_dn> keyword can be
228 used in the configuration file to enable this behaviour.
232 This sets the batch mode. In this mode no questions will be asked
233 and all certificates will be certified automatically.
235 =item B<-extensions section>
237 The section of the configuration file containing certificate extensions
238 to be added when a certificate is issued (defaults to B<x509_extensions>
239 unless the B<-extfile> option is used). If no extension section is
240 present then, a V1 certificate is created. If the extension section
241 is present (even if it is empty), then a V3 certificate is created. See the
242 L<x509v3_config(5)> manual page for details of the
243 extension section format.
245 =item B<-extfile file>
247 An additional configuration file to read certificate extensions from
248 (using the default section unless the B<-extensions> option is also
253 Specifying an engine (by its unique B<id> string) will cause B<ca>
254 to attempt to obtain a functional reference to the specified engine,
255 thus initialising it if needed. The engine will then be set as the default
256 for all available algorithms.
260 Supersedes subject name given in the request.
261 The arg must be formatted as I</type0=value0/type1=value1/type2=...>.
262 Keyword characters may be escaped by \ (backslash), and whitespace is retained.
263 Empty values are permitted, but the corresponding type will not be included
264 in the resulting certificate.
268 This option causes field values to be interpreted as UTF8 strings, by
269 default they are interpreted as ASCII. This means that the field
270 values, whether prompted from a terminal or obtained from a
271 configuration file, must be valid UTF8 strings.
273 =item B<-create_serial>
275 If reading serial from the text file as specified in the configuration
276 fails, specifying this option creates a new random serial to be used as next
278 To get random serial numbers, use the B<-rand_serial> flag instead; this
279 should only be used for simple error-recovery.
281 =item B<-rand_serial>
283 Generate a large random number to use as the serial number.
284 This overrides any option or configuration to use a serial number file.
286 =item B<-multivalue-rdn>
288 This option causes the -subj argument to be interpreted with full
289 support for multivalued RDNs. Example:
291 I</DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe>
293 If -multi-rdn is not used then the UID value is I<123456+CN=John Doe>.
295 =item B<-rand file...>
297 A file or files containing random data used to seed the random number
299 Multiple files can be specified separated by an OS-dependent character.
300 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
303 =item [B<-writerand file>]
305 Writes random data to the specified I<file> upon exit.
306 This can be used with a subsequent B<-rand> flag.
310 Specify the ID string to use when verifying an SM2 certificate. The ID string is
311 required by the SM2 signature algorithm for signing and verification.
315 Specify a binary ID string to use when signing or verifying using an SM2
316 certificate. The argument for this option is string of hexadecimal digits.
326 This option generates a CRL based on information in the index file.
328 =item B<-crldays num>
330 The number of days before the next CRL is due. That is the days from
331 now to place in the CRL nextUpdate field.
333 =item B<-crlhours num>
335 The number of hours before the next CRL is due.
337 =item B<-revoke filename>
339 A filename containing a certificate to revoke.
341 =item B<-valid filename>
343 A filename containing a certificate to add a Valid certificate entry.
345 =item B<-status serial>
347 Displays the revocation status of the certificate with the specified
348 serial number and exits.
352 Updates the database index to purge expired certificates.
354 =item B<-crl_reason reason>
356 Revocation reason, where B<reason> is one of: B<unspecified>, B<keyCompromise>,
357 B<CACompromise>, B<affiliationChanged>, B<superseded>, B<cessationOfOperation>,
358 B<certificateHold> or B<removeFromCRL>. The matching of B<reason> is case
359 insensitive. Setting any revocation reason will make the CRL v2.
361 In practice B<removeFromCRL> is not particularly useful because it is only used
362 in delta CRLs which are not currently implemented.
364 =item B<-crl_hold instruction>
366 This sets the CRL revocation reason code to B<certificateHold> and the hold
367 instruction to B<instruction> which must be an OID. Although any OID can be
368 used only B<holdInstructionNone> (the use of which is discouraged by RFC2459)
369 B<holdInstructionCallIssuer> or B<holdInstructionReject> will normally be used.
371 =item B<-crl_compromise time>
373 This sets the revocation reason to B<keyCompromise> and the compromise time to
374 B<time>. B<time> should be in GeneralizedTime format that is B<YYYYMMDDHHMMSSZ>.
376 =item B<-crl_CA_compromise time>
378 This is the same as B<crl_compromise> except the revocation reason is set to
381 =item B<-crlexts section>
383 The section of the configuration file containing CRL extensions to
384 include. If no CRL extension section is present then a V1 CRL is
385 created, if the CRL extension section is present (even if it is
386 empty) then a V2 CRL is created. The CRL extensions specified are
387 CRL extensions and B<not> CRL entry extensions. It should be noted
388 that some software (for example Netscape) can't handle V2 CRLs. See
389 L<x509v3_config(5)> manual page for details of the
390 extension section format.
394 =head1 CONFIGURATION FILE OPTIONS
396 The section of the configuration file containing options for B<ca>
397 is found as follows: If the B<-name> command line option is used,
398 then it names the section to be used. Otherwise the section to
399 be used must be named in the B<default_ca> option of the B<ca> section
400 of the configuration file (or in the default section of the
401 configuration file). Besides B<default_ca>, the following options are
402 read directly from the B<ca> section:
406 With the exception of B<RANDFILE>, this is probably a bug and may
407 change in future releases.
409 Many of the configuration file options are identical to command line
410 options. Where the option is present in the configuration file
411 and the command line the command line value is used. Where an
412 option is described as mandatory then it must be present in
413 the configuration file or the command line equivalent (if
420 This specifies a file containing additional B<OBJECT IDENTIFIERS>.
421 Each line of the file should consist of the numerical form of the
422 object identifier followed by white space then the short name followed
423 by white space and finally the long name.
427 This specifies a section in the configuration file containing extra
428 object identifiers. Each line should consist of the short name of the
429 object identifier followed by B<=> and the numerical form. The short
430 and long names are the same when this option is used.
432 =item B<new_certs_dir>
434 The same as the B<-outdir> command line option. It specifies
435 the directory where new certificates will be placed. Mandatory.
439 The same as B<-cert>. It gives the file containing the CA
440 certificate. Mandatory.
444 Same as the B<-keyfile> option. The file containing the
445 CA private key. Mandatory.
449 At startup the specified file is loaded into the random number generator,
450 and at exit 256 bytes will be written to it.
452 =item B<default_days>
454 The same as the B<-days> option. The number of days to certify
457 =item B<default_startdate>
459 The same as the B<-startdate> option. The start date to certify
460 a certificate for. If not set the current time is used.
462 =item B<default_enddate>
464 The same as the B<-enddate> option. Either this option or
465 B<default_days> (or the command line equivalents) must be
468 =item B<default_crl_hours default_crl_days>
470 The same as the B<-crlhours> and the B<-crldays> options. These
471 will only be used if neither command line option is present. At
472 least one of these must be present to generate a CRL.
476 The same as the B<-md> option. Mandatory except where the signing algorithm does
477 not require a digest (i.e. Ed25519 and Ed448).
481 The text database file to use. Mandatory. This file must be present
482 though initially it will be empty.
484 =item B<unique_subject>
486 If the value B<yes> is given, the valid certificate entries in the
487 database must have unique subjects. if the value B<no> is given,
488 several valid certificate entries may have the exact same subject.
489 The default value is B<yes>, to be compatible with older (pre 0.9.8)
490 versions of OpenSSL. However, to make CA certificate roll-over easier,
491 it's recommended to use the value B<no>, especially if combined with
492 the B<-selfsign> command line option.
494 Note that it is valid in some circumstances for certificates to be created
495 without any subject. In the case where there are multiple certificates without
496 subjects this does not count as a duplicate.
500 A text file containing the next serial number to use in hex. Mandatory.
501 This file must be present and contain a valid serial number.
505 A text file containing the next CRL number to use in hex. The crl number
506 will be inserted in the CRLs only if this file exists. If this file is
507 present, it must contain a valid CRL number.
509 =item B<x509_extensions>
511 The same as B<-extensions>.
513 =item B<crl_extensions>
515 The same as B<-crlexts>.
519 The same as B<-preserveDN>
523 The same as B<-noemailDN>. If you want the EMAIL field to be removed
524 from the DN of the certificate simply set this to 'no'. If not present
525 the default is to allow for the EMAIL filed in the certificate's DN.
529 The same as B<-msie_hack>
533 The same as B<-policy>. Mandatory. See the B<POLICY FORMAT> section
534 for more information.
536 =item B<name_opt>, B<cert_opt>
538 These options allow the format used to display the certificate details
539 when asking the user to confirm signing. All the options supported by
540 the B<x509> utilities B<-nameopt> and B<-certopt> switches can be used
541 here, except the B<no_signame> and B<no_sigdump> are permanently set
542 and cannot be disabled (this is because the certificate signature cannot
543 be displayed because the certificate has not been signed at this point).
545 For convenience the values B<ca_default> are accepted by both to produce
548 If neither option is present the format used in earlier versions of
549 OpenSSL is used. Use of the old format is B<strongly> discouraged because
550 it only displays fields mentioned in the B<policy> section, mishandles
551 multicharacter string types and does not display extensions.
553 =item B<copy_extensions>
555 Determines how extensions in certificate requests should be handled.
556 If set to B<none> or this option is not present then extensions are
557 ignored and not copied to the certificate. If set to B<copy> then any
558 extensions present in the request that are not already present are copied
559 to the certificate. If set to B<copyall> then all extensions in the
560 request are copied to the certificate: if the extension is already present
561 in the certificate it is deleted first. See the B<WARNINGS> section before
564 The main use of this option is to allow a certificate request to supply
565 values for certain extensions such as subjectAltName.
571 The policy section consists of a set of variables corresponding to
572 certificate DN fields. If the value is "match" then the field value
573 must match the same field in the CA certificate. If the value is
574 "supplied" then it must be present. If the value is "optional" then
575 it may be present. Any fields not mentioned in the policy section
576 are silently deleted, unless the B<-preserveDN> option is set but
577 this can be regarded more of a quirk than intended behaviour.
581 The input to the B<-spkac> command line option is a Netscape
582 signed public key and challenge. This will usually come from
583 the B<KEYGEN> tag in an HTML form to create a new private key.
584 It is however possible to create SPKACs using the B<spkac> utility.
586 The file should contain the variable SPKAC set to the value of
587 the SPKAC and also the required DN components as name value pairs.
588 If you need to include the same component twice then it can be
589 preceded by a number and a '.'.
591 When processing SPKAC format, the output is DER if the B<-out>
592 flag is used, but PEM format if sending to stdout or the B<-outdir>
597 Note: these examples assume that the B<ca> directory structure is
598 already set up and the relevant files already exist. This usually
599 involves creating a CA certificate and private key with B<req>, a
600 serial number file and an empty index file and placing them in
601 the relevant directories.
603 To use the sample configuration file below the directories demoCA,
604 demoCA/private and demoCA/newcerts would be created. The CA
605 certificate would be copied to demoCA/cacert.pem and its private
606 key to demoCA/private/cakey.pem. A file demoCA/serial would be
607 created containing for example "01" and the empty index file
611 Sign a certificate request:
613 openssl ca -in req.pem -out newcert.pem
615 Sign an SM2 certificate request:
617 openssl ca -in sm2.csr -out sm2.crt -md sm3 -sigopt "sm2_id:1234567812345678" -sm2-id "1234567812345678"
619 Sign a certificate request, using CA extensions:
621 openssl ca -in req.pem -extensions v3_ca -out newcert.pem
625 openssl ca -gencrl -out crl.pem
627 Sign several requests:
629 openssl ca -infiles req1.pem req2.pem req3.pem
631 Certify a Netscape SPKAC:
633 openssl ca -spkac spkac.txt
635 A sample SPKAC file (the SPKAC line has been truncated for clarity):
637 SPKAC=MIG0MGAwXDANBgkqhkiG9w0BAQEFAANLADBIAkEAn7PDhCeV/xIxUg8V70YRxK2A5
639 emailAddress=steve@openssl.org
643 A sample configuration file with the relevant sections for B<ca>:
646 default_ca = CA_default # The default ca section
650 dir = ./demoCA # top dir
651 database = $dir/index.txt # index file.
652 new_certs_dir = $dir/newcerts # new certs dir
654 certificate = $dir/cacert.pem # The CA cert
655 serial = $dir/serial # serial no file
656 #rand_serial = yes # for random serial#'s
657 private_key = $dir/private/cakey.pem# CA private key
658 RANDFILE = $dir/private/.rand # random number file
660 default_days = 365 # how long to certify for
661 default_crl_days= 30 # how long before next CRL
662 default_md = md5 # md to use
664 policy = policy_any # default policy
665 email_in_dn = no # Don't add the email into cert DN
667 name_opt = ca_default # Subject name display option
668 cert_opt = ca_default # Certificate display option
669 copy_extensions = none # Don't copy extensions from request
672 countryName = supplied
673 stateOrProvinceName = optional
674 organizationName = optional
675 organizationalUnitName = optional
676 commonName = supplied
677 emailAddress = optional
681 Note: the location of all files can change either by compile time options,
682 configuration file entries, environment variables or command line options.
683 The values below reflect the default values.
685 /usr/local/ssl/lib/openssl.cnf - master configuration file
686 ./demoCA - main CA directory
687 ./demoCA/cacert.pem - CA certificate
688 ./demoCA/private/cakey.pem - CA private key
689 ./demoCA/serial - CA serial number file
690 ./demoCA/serial.old - CA serial number backup file
691 ./demoCA/index.txt - CA text database file
692 ./demoCA/index.txt.old - CA text database backup file
693 ./demoCA/certs - certificate output file
694 ./demoCA/.rnd - CA random seed information
698 The text database index file is a critical part of the process and
699 if corrupted it can be difficult to fix. It is theoretically possible
700 to rebuild the index file from all the issued certificates and a current
701 CRL: however there is no option to do this.
703 V2 CRL features like delta CRLs are not currently supported.
705 Although several requests can be input and handled at once it is only
706 possible to include one SPKAC or self-signed certificate.
710 The use of an in-memory text database can cause problems when large
711 numbers of certificates are present because, as the name implies
712 the database has to be kept in memory.
714 The B<ca> command really needs rewriting or the required functionality
715 exposed at either a command or interface level so a more friendly utility
716 (perl script or GUI) can handle things properly. The script
717 B<CA.pl> helps a little but not very much.
719 Any fields in a request that are not present in a policy are silently
720 deleted. This does not happen if the B<-preserveDN> option is used. To
721 enforce the absence of the EMAIL field within the DN, as suggested by
722 RFCs, regardless the contents of the request' subject the B<-noemailDN>
723 option can be used. The behaviour should be more friendly and
726 Canceling some commands by refusing to certify a certificate can
727 create an empty file.
731 The B<ca> command is quirky and at times downright unfriendly.
733 The B<ca> utility was originally meant as an example of how to do things
734 in a CA. It was not supposed to be used as a full blown CA itself:
735 nevertheless some people are using it for this purpose.
737 The B<ca> command is effectively a single user command: no locking is
738 done on the various files and attempts to run more than one B<ca> command
739 on the same database can have unpredictable results.
741 The B<copy_extensions> option should be used with caution. If care is
742 not taken then it can be a security risk. For example if a certificate
743 request contains a basicConstraints extension with CA:TRUE and the
744 B<copy_extensions> value is set to B<copyall> and the user does not spot
745 this when the certificate is displayed then this will hand the requester
746 a valid CA certificate.
748 This situation can be avoided by setting B<copy_extensions> to B<copy>
749 and including basicConstraints with CA:FALSE in the configuration file.
750 Then if the request contains a basicConstraints extension it will be
753 It is advisable to also include values for other extensions such
754 as B<keyUsage> to prevent a request supplying its own values.
756 Additional restrictions can be placed on the CA certificate itself.
757 For example if the CA certificate has:
759 basicConstraints = CA:TRUE, pathlen:0
761 then even if a certificate is issued with CA:TRUE it will not be valid.
765 Since OpenSSL 1.1.1, the program follows RFC5280. Specifically,
766 certificate validity period (specified by any of B<-startdate>,
767 B<-enddate> and B<-days>) will be encoded as UTCTime if the dates are
768 earlier than year 2049 (included), and as GeneralizedTime if the dates
769 are in year 2050 or later.
773 L<req(1)>, L<spkac(1)>, L<x509(1)>, L<CA.pl(1)>,
774 L<config(5)>, L<x509v3_config(5)>
778 Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
780 Licensed under the Apache License 2.0 (the "License"). You may not use
781 this file except in compliance with the License. You can obtain a copy
782 in the file LICENSE in the source distribution or at
783 L<https://www.openssl.org/source/license.html>.