7 ca - sample minimal CA application
19 [B<-crl_reason reason>]
20 [B<-crl_hold instruction>]
21 [B<-crl_compromise time>]
22 [B<-crl_CA_compromise time>]
48 [B<-extensions section>]
57 The B<ca> command is a minimal CA application. It can be used
58 to sign certificate requests in a variety of forms and generate
59 CRLs it also maintains a text database of issued certificates
62 The options descriptions will be divided into each purpose.
68 =item B<-config filename>
70 specifies the configuration file to use.
72 =item B<-name section>
74 specifies the configuration file section to use (overrides
75 B<default_ca> in the B<ca> section).
79 an input filename containing a single certificate request to be
82 =item B<-ss_cert filename>
84 a single self signed certificate to be signed by the CA.
86 =item B<-spkac filename>
88 a file containing a single Netscape signed public key and challenge
89 and additional field values to be signed by the CA. See the B<SPKAC FORMAT>
90 section for information on the required input and output format.
94 if present this should be the last option, all subsequent arguments
95 are assumed to the the names of files containing certificate requests.
97 =item B<-out filename>
99 the output file to output certificates to. The default is standard
100 output. The certificate details will also be printed out to this
101 file in PEM format (except that B<-spkac> outputs DER format).
103 =item B<-outdir directory>
105 the directory to output certificates to. The certificate will be
106 written to a filename consisting of the serial number in hex with
111 the CA certificate file.
113 =item B<-keyfile filename>
115 the private key to sign requests with.
117 =item B<-keyform PEM|DER>
119 the format of the data in the private key file.
122 =item B<-key password>
124 the password used to encrypt the private key. Since on some
125 systems the command line arguments are visible (e.g. Unix with
126 the 'ps' utility) this option should be used with caution.
130 indicates the issued certificates are to be signed with the key
131 the certificate requests were signed with (given with B<-keyfile>).
132 Cerificate requests signed with a different key are ignored. If
133 B<-spkac>, B<-ss_cert> or B<-gencrl> are given, B<-selfsign> is
136 A consequence of using B<-selfsign> is that the self-signed
137 certificate appears among the entries in the certificate database
138 (see the configuration option B<database>), and uses the same
139 serial number counter as all other certificates sign with the
140 self-signed certificate.
144 the key password source. For more information about the format of B<arg>
145 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
149 this prints extra details about the operations being performed.
153 don't output the text form of a certificate to the output file.
155 =item B<-startdate date>
157 this allows the start date to be explicitly set. The format of the
158 date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure).
160 =item B<-enddate date>
162 this allows the expiry date to be explicitly set. The format of the
163 date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure).
167 the number of days to certify the certificate for.
171 the message digest to use. Possible values include md5, sha1 and mdc2.
172 This option also applies to CRLs.
176 this option defines the CA "policy" to use. This is a section in
177 the configuration file which decides which fields should be mandatory
178 or match the CA certificate. Check out the B<POLICY FORMAT> section
179 for more information.
183 this is a legacy option to make B<ca> work with very old versions of
184 the IE certificate enrollment control "certenr3". It used UniversalStrings
185 for almost everything. Since the old control has various security bugs
186 its use is strongly discouraged. The newer control "Xenroll" does not
191 Normally the DN order of a certificate is the same as the order of the
192 fields in the relevant policy section. When this option is set the order
193 is the same as the request. This is largely for compatibility with the
194 older IE enrollment control which would only accept certificates if their
195 DNs match the order of the request. This is not needed for Xenroll.
199 The DN of a certificate can contain the EMAIL field if present in the
200 request DN, however it is good policy just having the e-mail set into
201 the altName extension of the certificate. When this option is set the
202 EMAIL field is removed from the certificate' subject and set only in
203 the, eventually present, extensions. The B<email_in_dn> keyword can be
204 used in the configuration file to enable this behaviour.
208 this sets the batch mode. In this mode no questions will be asked
209 and all certificates will be certified automatically.
211 =item B<-extensions section>
213 the section of the configuration file containing certificate extensions
214 to be added when a certificate is issued (defaults to B<x509_extensions>
215 unless the B<-extfile> option is used). If no extension section is
216 present then, a V1 certificate is created. If the extension section
217 is present (even if it is empty), then a V3 certificate is created. See the:w
218 L<x509v3_config(5)|x509v3_config(5)> manual page for details of the
219 extension section format.
221 =item B<-extfile file>
223 an additional configuration file to read certificate extensions from
224 (using the default section unless the B<-extensions> option is also
229 specifying an engine (by its unique B<id> string) will cause B<ca>
230 to attempt to obtain a functional reference to the specified engine,
231 thus initialising it if needed. The engine will then be set as the default
232 for all available algorithms.
236 supersedes subject name given in the request.
237 The arg must be formatted as I</type0=value0/type1=value1/type2=...>,
238 characters may be escaped by \ (backslash), no spaces are skipped.
242 this option causes field values to be interpreted as UTF8 strings, by
243 default they are interpreted as ASCII. This means that the field
244 values, whether prompted from a terminal or obtained from a
245 configuration file, must be valid UTF8 strings.
247 =item B<-multivalue-rdn>
249 this option causes the -subj argument to be interpretedt with full
250 support for multivalued RDNs. Example:
252 I</DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe>
254 If -multi-rdn is not used then the UID value is I<123456+CN=John Doe>.
264 this option generates a CRL based on information in the index file.
266 =item B<-crldays num>
268 the number of days before the next CRL is due. That is the days from
269 now to place in the CRL nextUpdate field.
271 =item B<-crlhours num>
273 the number of hours before the next CRL is due.
275 =item B<-revoke filename>
277 a filename containing a certificate to revoke.
279 =item B<-status serial>
281 displays the revocation status of the certificate with the specified
282 serial number and exits.
286 Updates the database index to purge expired certificates.
288 =item B<-crl_reason reason>
290 revocation reason, where B<reason> is one of: B<unspecified>, B<keyCompromise>,
291 B<CACompromise>, B<affiliationChanged>, B<superseded>, B<cessationOfOperation>,
292 B<certificateHold> or B<removeFromCRL>. The matching of B<reason> is case
293 insensitive. Setting any revocation reason will make the CRL v2.
295 In practive B<removeFromCRL> is not particularly useful because it is only used
296 in delta CRLs which are not currently implemented.
298 =item B<-crl_hold instruction>
300 This sets the CRL revocation reason code to B<certificateHold> and the hold
301 instruction to B<instruction> which must be an OID. Although any OID can be
302 used only B<holdInstructionNone> (the use of which is discouraged by RFC2459)
303 B<holdInstructionCallIssuer> or B<holdInstructionReject> will normally be used.
305 =item B<-crl_compromise time>
307 This sets the revocation reason to B<keyCompromise> and the compromise time to
308 B<time>. B<time> should be in GeneralizedTime format that is B<YYYYMMDDHHMMSSZ>.
310 =item B<-crl_CA_compromise time>
312 This is the same as B<crl_compromise> except the revocation reason is set to
315 =item B<-crlexts section>
317 the section of the configuration file containing CRL extensions to
318 include. If no CRL extension section is present then a V1 CRL is
319 created, if the CRL extension section is present (even if it is
320 empty) then a V2 CRL is created. The CRL extensions specified are
321 CRL extensions and B<not> CRL entry extensions. It should be noted
322 that some software (for example Netscape) can't handle V2 CRLs. See
323 L<x509v3_config(5)|x509v3_config(5)> manual page for details of the
324 extension section format.
328 =head1 CONFIGURATION FILE OPTIONS
330 The section of the configuration file containing options for B<ca>
331 is found as follows: If the B<-name> command line option is used,
332 then it names the section to be used. Otherwise the section to
333 be used must be named in the B<default_ca> option of the B<ca> section
334 of the configuration file (or in the default section of the
335 configuration file). Besides B<default_ca>, the following options are
336 read directly from the B<ca> section:
340 With the exception of B<RANDFILE>, this is probably a bug and may
341 change in future releases.
343 Many of the configuration file options are identical to command line
344 options. Where the option is present in the configuration file
345 and the command line the command line value is used. Where an
346 option is described as mandatory then it must be present in
347 the configuration file or the command line equivalent (if
354 This specifies a file containing additional B<OBJECT IDENTIFIERS>.
355 Each line of the file should consist of the numerical form of the
356 object identifier followed by white space then the short name followed
357 by white space and finally the long name.
361 This specifies a section in the configuration file containing extra
362 object identifiers. Each line should consist of the short name of the
363 object identifier followed by B<=> and the numerical form. The short
364 and long names are the same when this option is used.
366 =item B<new_certs_dir>
368 the same as the B<-outdir> command line option. It specifies
369 the directory where new certificates will be placed. Mandatory.
373 the same as B<-cert>. It gives the file containing the CA
374 certificate. Mandatory.
378 same as the B<-keyfile> option. The file containing the
379 CA private key. Mandatory.
383 a file used to read and write random number seed information, or
384 an EGD socket (see L<RAND_egd(3)|RAND_egd(3)>).
386 =item B<default_days>
388 the same as the B<-days> option. The number of days to certify
391 =item B<default_startdate>
393 the same as the B<-startdate> option. The start date to certify
394 a certificate for. If not set the current time is used.
396 =item B<default_enddate>
398 the same as the B<-enddate> option. Either this option or
399 B<default_days> (or the command line equivalents) must be
402 =item B<default_crl_hours default_crl_days>
404 the same as the B<-crlhours> and the B<-crldays> options. These
405 will only be used if neither command line option is present. At
406 least one of these must be present to generate a CRL.
410 the same as the B<-md> option. The message digest to use. Mandatory.
414 the text database file to use. Mandatory. This file must be present
415 though initially it will be empty.
417 =item B<unique_subject>
419 if the value B<yes> is given, the valid certificate entries in the
420 database must have unique subjects. if the value B<no> is given,
421 several valid certificate entries may have the exact same subject.
422 The default value is B<yes>, to be compatible with older (pre 0.9.8)
423 versions of OpenSSL. However, to make CA certificate roll-over easier,
424 it's recommended to use the value B<no>, especially if combined with
425 the B<-selfsign> command line option.
427 Note that it is valid in some circumstances for certificates to be created
428 without any subject. In the case where there are multiple certificates without
429 subjects this does not count as a duplicate.
433 a text file containing the next serial number to use in hex. Mandatory.
434 This file must be present and contain a valid serial number.
438 a text file containing the next CRL number to use in hex. The crl number
439 will be inserted in the CRLs only if this file exists. If this file is
440 present, it must contain a valid CRL number.
442 =item B<x509_extensions>
444 the same as B<-extensions>.
446 =item B<crl_extensions>
448 the same as B<-crlexts>.
452 the same as B<-preserveDN>
456 the same as B<-noemailDN>. If you want the EMAIL field to be removed
457 from the DN of the certificate simply set this to 'no'. If not present
458 the default is to allow for the EMAIL filed in the certificate's DN.
462 the same as B<-msie_hack>
466 the same as B<-policy>. Mandatory. See the B<POLICY FORMAT> section
467 for more information.
469 =item B<name_opt>, B<cert_opt>
471 these options allow the format used to display the certificate details
472 when asking the user to confirm signing. All the options supported by
473 the B<x509> utilities B<-nameopt> and B<-certopt> switches can be used
474 here, except the B<no_signame> and B<no_sigdump> are permanently set
475 and cannot be disabled (this is because the certificate signature cannot
476 be displayed because the certificate has not been signed at this point).
478 For convenience the values B<ca_default> are accepted by both to produce
481 If neither option is present the format used in earlier versions of
482 OpenSSL is used. Use of the old format is B<strongly> discouraged because
483 it only displays fields mentioned in the B<policy> section, mishandles
484 multicharacter string types and does not display extensions.
486 =item B<copy_extensions>
488 determines how extensions in certificate requests should be handled.
489 If set to B<none> or this option is not present then extensions are
490 ignored and not copied to the certificate. If set to B<copy> then any
491 extensions present in the request that are not already present are copied
492 to the certificate. If set to B<copyall> then all extensions in the
493 request are copied to the certificate: if the extension is already present
494 in the certificate it is deleted first. See the B<WARNINGS> section before
497 The main use of this option is to allow a certificate request to supply
498 values for certain extensions such as subjectAltName.
504 The policy section consists of a set of variables corresponding to
505 certificate DN fields. If the value is "match" then the field value
506 must match the same field in the CA certificate. If the value is
507 "supplied" then it must be present. If the value is "optional" then
508 it may be present. Any fields not mentioned in the policy section
509 are silently deleted, unless the B<-preserveDN> option is set but
510 this can be regarded more of a quirk than intended behaviour.
514 The input to the B<-spkac> command line option is a Netscape
515 signed public key and challenge. This will usually come from
516 the B<KEYGEN> tag in an HTML form to create a new private key.
517 It is however possible to create SPKACs using the B<spkac> utility.
519 The file should contain the variable SPKAC set to the value of
520 the SPKAC and also the required DN components as name value pairs.
521 If you need to include the same component twice then it can be
522 preceded by a number and a '.'.
524 When processing SPKAC format, the output is DER if the B<-out>
525 flag is used, but PEM format if sending to stdout or the B<-outdir>
530 Note: these examples assume that the B<ca> directory structure is
531 already set up and the relevant files already exist. This usually
532 involves creating a CA certificate and private key with B<req>, a
533 serial number file and an empty index file and placing them in
534 the relevant directories.
536 To use the sample configuration file below the directories demoCA,
537 demoCA/private and demoCA/newcerts would be created. The CA
538 certificate would be copied to demoCA/cacert.pem and its private
539 key to demoCA/private/cakey.pem. A file demoCA/serial would be
540 created containing for example "01" and the empty index file
544 Sign a certificate request:
546 openssl ca -in req.pem -out newcert.pem
548 Sign a certificate request, using CA extensions:
550 openssl ca -in req.pem -extensions v3_ca -out newcert.pem
554 openssl ca -gencrl -out crl.pem
556 Sign several requests:
558 openssl ca -infiles req1.pem req2.pem req3.pem
560 Certify a Netscape SPKAC:
562 openssl ca -spkac spkac.txt
564 A sample SPKAC file (the SPKAC line has been truncated for clarity):
566 SPKAC=MIG0MGAwXDANBgkqhkiG9w0BAQEFAANLADBIAkEAn7PDhCeV/xIxUg8V70YRxK2A5
568 emailAddress=steve@openssl.org
572 A sample configuration file with the relevant sections for B<ca>:
575 default_ca = CA_default # The default ca section
579 dir = ./demoCA # top dir
580 database = $dir/index.txt # index file.
581 new_certs_dir = $dir/newcerts # new certs dir
583 certificate = $dir/cacert.pem # The CA cert
584 serial = $dir/serial # serial no file
585 private_key = $dir/private/cakey.pem# CA private key
586 RANDFILE = $dir/private/.rand # random number file
588 default_days = 365 # how long to certify for
589 default_crl_days= 30 # how long before next CRL
590 default_md = md5 # md to use
592 policy = policy_any # default policy
593 email_in_dn = no # Don't add the email into cert DN
595 name_opt = ca_default # Subject name display option
596 cert_opt = ca_default # Certificate display option
597 copy_extensions = none # Don't copy extensions from request
600 countryName = supplied
601 stateOrProvinceName = optional
602 organizationName = optional
603 organizationalUnitName = optional
604 commonName = supplied
605 emailAddress = optional
609 Note: the location of all files can change either by compile time options,
610 configuration file entries, environment variables or command line options.
611 The values below reflect the default values.
613 /usr/local/ssl/lib/openssl.cnf - master configuration file
614 ./demoCA - main CA directory
615 ./demoCA/cacert.pem - CA certificate
616 ./demoCA/private/cakey.pem - CA private key
617 ./demoCA/serial - CA serial number file
618 ./demoCA/serial.old - CA serial number backup file
619 ./demoCA/index.txt - CA text database file
620 ./demoCA/index.txt.old - CA text database backup file
621 ./demoCA/certs - certificate output file
622 ./demoCA/.rnd - CA random seed information
624 =head1 ENVIRONMENT VARIABLES
626 B<OPENSSL_CONF> reflects the location of master configuration file it can
627 be overridden by the B<-config> command line option.
631 The text database index file is a critical part of the process and
632 if corrupted it can be difficult to fix. It is theoretically possible
633 to rebuild the index file from all the issued certificates and a current
634 CRL: however there is no option to do this.
636 V2 CRL features like delta CRLs are not currently supported.
638 Although several requests can be input and handled at once it is only
639 possible to include one SPKAC or self signed certificate.
643 The use of an in memory text database can cause problems when large
644 numbers of certificates are present because, as the name implies
645 the database has to be kept in memory.
647 The B<ca> command really needs rewriting or the required functionality
648 exposed at either a command or interface level so a more friendly utility
649 (perl script or GUI) can handle things properly. The scripts B<CA.sh> and
650 B<CA.pl> help a little but not very much.
652 Any fields in a request that are not present in a policy are silently
653 deleted. This does not happen if the B<-preserveDN> option is used. To
654 enforce the absence of the EMAIL field within the DN, as suggested by
655 RFCs, regardless the contents of the request' subject the B<-noemailDN>
656 option can be used. The behaviour should be more friendly and
659 Cancelling some commands by refusing to certify a certificate can
660 create an empty file.
664 The B<ca> command is quirky and at times downright unfriendly.
666 The B<ca> utility was originally meant as an example of how to do things
667 in a CA. It was not supposed to be used as a full blown CA itself:
668 nevertheless some people are using it for this purpose.
670 The B<ca> command is effectively a single user command: no locking is
671 done on the various files and attempts to run more than one B<ca> command
672 on the same database can have unpredictable results.
674 The B<copy_extensions> option should be used with caution. If care is
675 not taken then it can be a security risk. For example if a certificate
676 request contains a basicConstraints extension with CA:TRUE and the
677 B<copy_extensions> value is set to B<copyall> and the user does not spot
678 this when the certificate is displayed then this will hand the requestor
679 a valid CA certificate.
681 This situation can be avoided by setting B<copy_extensions> to B<copy>
682 and including basicConstraints with CA:FALSE in the configuration file.
683 Then if the request contains a basicConstraints extension it will be
686 It is advisable to also include values for other extensions such
687 as B<keyUsage> to prevent a request supplying its own values.
689 Additional restrictions can be placed on the CA certificate itself.
690 For example if the CA certificate has:
692 basicConstraints = CA:TRUE, pathlen:0
694 then even if a certificate is issued with CA:TRUE it will not be valid.
698 L<req(1)|req(1)>, L<spkac(1)|spkac(1)>, L<x509(1)|x509(1)>, L<CA.pl(1)|CA.pl(1)>,
699 L<config(5)|config(5)>, L<x509v3_config(5)|x509v3_config(5)>