6 ca - sample minimal CA application
40 [B<-extensions section>]
45 The B<ca> command is a minimal CA application. It can be used
46 to sign certificate requests in a variety of forms and generate
47 CRLs it also maintains a text database of issued certificates
50 The options descriptions will be divided into each purpose.
56 =item B<-config filename>
58 specifies the configuration file to use.
62 an input filename containing a single certificate request to be
65 =item B<-ss_cert filename>
67 a single self signed certificate to be signed by the CA.
69 =item B<-spkac filename>
71 a file containing a single Netscape signed public key and challenge
72 and additional field values to be signed by the CA. See the B<NOTES>
73 section for information on the required format.
77 if present this should be the last option, all subsequent arguments
78 are assumed to the the names of files containing certificate requests.
80 =item B<-out filename>
82 the output file to output certificates to. The default is standard
83 output. The certificate details will also be printed out to this
86 =item B<-outdir directory>
88 the directory to output certificates to. The certificate will be
89 written to a filename consisting of the serial number in hex with
94 the CA certificate file.
96 =item B<-keyfile filename>
98 the private key to sign requests with.
100 =item B<-key password>
102 the password used to encrypt the private key. Since on some
103 systems the command line arguments are visible (e.g. Unix with
104 the 'ps' utility) this option should be used with caution.
108 the key password source. For more information about the format of B<arg>
109 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
113 this prints extra details about the operations being performed.
117 don't output the text form of a certificate to the output file.
119 =item B<-startdate date>
121 this allows the start date to be explicitly set. The format of the
122 date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure).
124 =item B<-enddate date>
126 this allows the expiry date to be explicitly set. The format of the
127 date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure).
131 the number of days to certify the certificate for.
135 the message digest to use. Possible values include md5, sha1 and mdc2.
136 This option also applies to CRLs.
140 this option defines the CA "policy" to use. This is a section in
141 the configuration file which decides which fields should be mandatory
142 or match the CA certificate. Check out the B<POLICY FORMAT> section
143 for more information.
147 this is a legacy option to make B<ca> work with very old versions of
148 the IE certificate enrollment control "certenr3". It used UniversalStrings
149 for almost everything. Since the old control has various security bugs
150 its use is strongly discouraged. The newer control "Xenroll" does not
155 Normally the DN order of a certificate is the same as the order of the
156 fields in the relevant policy section. When this option is set the order
157 is the same as the request. This is largely for compatibility with the
158 older IE enrollment control which would only accept certificates if their
159 DNs match the order of the request. This is not needed for Xenroll.
163 The DN of a certificate can contain the EMAIL field if present in the
164 request DN, however it is good policy just having the e-mail set into
165 the altName extension of the certificate. When this option is set the
166 EMAIL field is removed from the certificate' subject and set only in
167 the, eventually present, extensions. The B<email_in_dn> keyword can be
168 used in the configuration file to enable this behaviour.
172 this sets the batch mode. In this mode no questions will be asked
173 and all certificates will be certified automatically.
175 =item B<-extensions section>
177 the section of the configuration file containing certificate extensions
178 to be added when a certificate is issued (defaults to B<x509_extensions>
179 unless the B<-extfile> option is used). If no extension section is
180 present then, a V1 certificate is created. If the extension section
181 is present (even if it is empty), then a V3 certificate is created.
183 =item B<-extfile file>
185 an additional configuration file to read certificate extensions from
186 (using the default section unless the B<-extensions> option is also
197 this option generates a CRL based on information in the index file.
199 =item B<-crldays num>
201 the number of days before the next CRL is due. That is the days from
202 now to place in the CRL nextUpdate field.
204 =item B<-crlhours num>
206 the number of hours before the next CRL is due.
208 =item B<-revoke filename>
210 a filename containing a certificate to revoke.
214 supersedes subject name given in the request
216 =item B<-crlexts section>
218 the section of the configuration file containing CRL extensions to
219 include. If no CRL extension section is present then a V1 CRL is
220 created, if the CRL extension section is present (even if it is
221 empty) then a V2 CRL is created. The CRL extensions specified are
222 CRL extensions and B<not> CRL entry extensions. It should be noted
223 that some software (for example Netscape) can't handle V2 CRLs.
227 =head1 CONFIGURATION FILE OPTIONS
229 The options for B<ca> are contained in the B<ca> section of the
230 configuration file. Many of these are identical to command line
231 options. Where the option is present in the configuration file
232 and the command line the command line value is used. Where an
233 option is described as mandatory then it must be present in
234 the configuration file or the command line equivalent (if
241 This specifies a file containing additional B<OBJECT IDENTIFIERS>.
242 Each line of the file should consist of the numerical form of the
243 object identifier followed by white space then the short name followed
244 by white space and finally the long name.
248 This specifies a section in the configuration file containing extra
249 object identifiers. Each line should consist of the short name of the
250 object identifier followed by B<=> and the numerical form. The short
251 and long names are the same when this option is used.
253 =item B<new_certs_dir>
255 the same as the B<-outdir> command line option. It specifies
256 the directory where new certificates will be placed. Mandatory.
260 the same as B<-cert>. It gives the file containing the CA
261 certificate. Mandatory.
265 same as the B<-keyfile> option. The file containing the
266 CA private key. Mandatory.
270 a file used to read and write random number seed information, or
271 an EGD socket (see L<RAND_egd(3)|RAND_egd(3)>).
273 =item B<default_days>
275 the same as the B<-days> option. The number of days to certify
278 =item B<default_startdate>
280 the same as the B<-startdate> option. The start date to certify
281 a certificate for. If not set the current time is used.
283 =item B<default_enddate>
285 the same as the B<-enddate> option. Either this option or
286 B<default_days> (or the command line equivalents) must be
289 =item B<default_crl_hours default_crl_days>
291 the same as the B<-crlhours> and the B<-crldays> options. These
292 will only be used if neither command line option is present. At
293 least one of these must be present to generate a CRL.
297 the same as the B<-md> option. The message digest to use. Mandatory.
301 the text database file to use. Mandatory. This file must be present
302 though initially it will be empty.
306 a text file containing the next serial number to use in hex. Mandatory.
307 This file must be present and contain a valid serial number.
309 =item B<x509_extensions>
311 the same as B<-extensions>.
313 =item B<crl_extensions>
315 the same as B<-crlexts>.
319 the same as B<-preserveDN>
323 the same as B<-noemailDN>. If you want the EMAIL field to be removed
324 from the DN of the certificate simply set this to 'no'. If not present
325 the default is to allow for the EMAIL filed in the certificate's DN.
329 the same as B<-msie_hack>
333 the same as B<-policy>. Mandatory. See the B<POLICY FORMAT> section
334 for more information.
336 =item B<nameopt>, B<certopt>
338 these options allow the format used to display the certificate details
339 when asking the user to confirm signing. All the options supported by
340 the B<x509> utilities B<-nameopt> and B<-certopt> switches can be used
341 here, except the B<no_signame> and B<no_sigdump> are permanently set
342 and cannot be disabled (this is because the certificate signature cannot
343 be displayed because the certificate has not been signed at this point).
345 For convenience the values B<default_ca> are accepted by both to produce
348 If neither option is present the format used in earlier versions of
349 OpenSSL is used. Use of the old format is B<strongly> discouraged because
350 it only displays fields mentioned in the B<policy> section, mishandles
351 multicharacter string types and does not display extensions.
353 =item B<copy_extensions>
355 determines how extensions in certificate requests should be handled.
356 If set to B<none> or this option is not present then extensions are
357 ignored and not copied to the certificate. If set to B<copy> then any
358 extensions present in the request that are not already present are copied
359 to the certificate. If set to B<copyall> then all extensions in the
360 request are copied to the certificate: if the extension is already present
361 in the certificate it is deleted first. See the B<WARNINGS> section before
364 The main use of this option is to allow a certificate request to supply
365 values for certain extensions such as subjectAltName.
371 The policy section consists of a set of variables corresponding to
372 certificate DN fields. If the value is "match" then the field value
373 must match the same field in the CA certificate. If the value is
374 "supplied" then it must be present. If the value is "optional" then
375 it may be present. Any fields not mentioned in the policy section
376 are silently deleted, unless the B<-preserveDN> option is set but
377 this can be regarded more of a quirk than intended behaviour.
381 The input to the B<-spkac> command line option is a Netscape
382 signed public key and challenge. This will usually come from
383 the B<KEYGEN> tag in an HTML form to create a new private key.
384 It is however possible to create SPKACs using the B<spkac> utility.
386 The file should contain the variable SPKAC set to the value of
387 the SPKAC and also the required DN components as name value pairs.
388 If you need to include the same component twice then it can be
389 preceded by a number and a '.'.
393 Note: these examples assume that the B<ca> directory structure is
394 already set up and the relevant files already exist. This usually
395 involves creating a CA certificate and private key with B<req>, a
396 serial number file and an empty index file and placing them in
397 the relevant directories.
399 To use the sample configuration file below the directories demoCA,
400 demoCA/private and demoCA/newcerts would be created. The CA
401 certificate would be copied to demoCA/cacert.pem and its private
402 key to demoCA/private/cakey.pem. A file demoCA/serial would be
403 created containing for example "01" and the empty index file
407 Sign a certificate request:
409 openssl ca -in req.pem -out newcert.pem
411 Sign a certificate request, using CA extensions:
413 openssl ca -in req.pem -extensions v3_ca -out newcert.pem
417 openssl ca -gencrl -out crl.pem
419 Sign several requests:
421 openssl ca -infiles req1.pem req2.pem req3.pem
423 Certify a Netscape SPKAC:
425 openssl ca -spkac spkac.txt
427 A sample SPKAC file (the SPKAC line has been truncated for clarity):
429 SPKAC=MIG0MGAwXDANBgkqhkiG9w0BAQEFAANLADBIAkEAn7PDhCeV/xIxUg8V70YRxK2A5
431 emailAddress=steve@openssl.org
435 A sample configuration file with the relevant sections for B<ca>:
438 default_ca = CA_default # The default ca section
442 dir = ./demoCA # top dir
443 database = $dir/index.txt # index file.
444 new_certs_dir = $dir/newcerts # new certs dir
446 certificate = $dir/cacert.pem # The CA cert
447 serial = $dir/serial # serial no file
448 private_key = $dir/private/cakey.pem# CA private key
449 RANDFILE = $dir/private/.rand # random number file
451 default_days = 365 # how long to certify for
452 default_crl_days= 30 # how long before next CRL
453 default_md = md5 # md to use
455 policy = policy_any # default policy
456 email_in_dn = no # Don't add the email into cert DN
458 nameopt = default_ca # Subject name display option
459 certopt = default_ca # Certificate display option
460 copy_extensions = none # Don't copy extensions from request
463 countryName = supplied
464 stateOrProvinceName = optional
465 organizationName = optional
466 organizationalUnitName = optional
467 commonName = supplied
468 emailAddress = optional
472 The B<ca> command is quirky and at times downright unfriendly.
474 The B<ca> utility was originally meant as an example of how to do things
475 in a CA. It was not supposed to be used as a full blown CA itself:
476 nevertheless some people are using it for this purpose.
478 The B<ca> command is effectively a single user command: no locking is
479 done on the various files and attempts to run more than one B<ca> command
480 on the same database can have unpredictable results.
484 Note: the location of all files can change either by compile time options,
485 configuration file entries, environment variables or command line options.
486 The values below reflect the default values.
488 /usr/local/ssl/lib/openssl.cnf - master configuration file
489 ./demoCA - main CA directory
490 ./demoCA/cacert.pem - CA certificate
491 ./demoCA/private/cakey.pem - CA private key
492 ./demoCA/serial - CA serial number file
493 ./demoCA/serial.old - CA serial number backup file
494 ./demoCA/index.txt - CA text database file
495 ./demoCA/index.txt.old - CA text database backup file
496 ./demoCA/certs - certificate output file
497 ./demoCA/.rnd - CA random seed information
499 =head1 ENVIRONMENT VARIABLES
501 B<OPENSSL_CONF> reflects the location of master configuration file it can
502 be overridden by the B<-config> command line option.
506 The text database index file is a critical part of the process and
507 if corrupted it can be difficult to fix. It is theoretically possible
508 to rebuild the index file from all the issued certificates and a current
509 CRL: however there is no option to do this.
511 CRL entry extensions cannot currently be created: only CRL extensions
514 V2 CRL features like delta CRL support and CRL numbers are not currently
517 Although several requests can be input and handled at once it is only
518 possible to include one SPKAC or self signed certificate.
522 The use of an in memory text database can cause problems when large
523 numbers of certificates are present because, as the name implies
524 the database has to be kept in memory.
526 It is not possible to certify two certificates with the same DN: this
527 is a side effect of how the text database is indexed and it cannot easily
528 be fixed without introducing other problems. Some S/MIME clients can use
529 two certificates with the same DN for separate signing and encryption
532 The B<ca> command really needs rewriting or the required functionality
533 exposed at either a command or interface level so a more friendly utility
534 (perl script or GUI) can handle things properly. The scripts B<CA.sh> and
535 B<CA.pl> help a little but not very much.
537 Any fields in a request that are not present in a policy are silently
538 deleted. This does not happen if the B<-preserveDN> option is used. To
539 enforce the absence of the EMAIL field within the DN, as suggested by
540 RFCs, regardless the contents of the request' subject the B<-noemailDN>
541 option can be used. The behaviour should be more friendly and
544 Cancelling some commands by refusing to certify a certificate can
545 create an empty file.
549 The B<copy_extensions> option should be used with caution. If care is
550 not taken then it can be a security risk. For example if a certificate
551 request contains a basicConstraints extension with CA:TRUE and the
552 B<copy_extensions> value is set to B<copyall> and the user does not spot
553 this when the certificate is displayed then this will hand the requestor
554 a valid CA certificate.
556 This situation can be avoided by setting B<copy_extensions> to B<copy>
557 and including basicConstraints with CA:FALSE in the configuration file.
558 Then if the request contains a basicConstraints extension it will be
561 It is advisable to also include values for other extensions such
562 as B<keyUsage> to prevent a request supplying its own values.
564 Additional restrictions can be placed on the CA certificate itself.
565 For example if the CA certificate has:
567 basicConstraints = CA:TRUE, pathlen:0
569 then even if a certificate is issued with CA:TRUE it will not be valid.
573 L<req(1)|req(1)>, L<spkac(1)|spkac(1)>, L<x509(1)|x509(1)>, L<CA.pl(1)|CA.pl(1)>,
574 L<config(5)|config(5)>