6 ca - sample minimal CA application
16 [B<-crl_reason reason>]
17 [B<-crl_hold instruction>]
18 [B<-crl_compromise time>]
19 [B<-crl_CA_compromise time>]
44 [B<-extensions section>]
50 The B<ca> command is a minimal CA application. It can be used
51 to sign certificate requests in a variety of forms and generate
52 CRLs it also maintains a text database of issued certificates
55 The options descriptions will be divided into each purpose.
61 =item B<-config filename>
63 specifies the configuration file to use.
65 =item B<-name section>
67 specifies the configuration file section to use (overrides
68 B<default_ca> in the B<ca> section).
72 an input filename containing a single certificate request to be
75 =item B<-ss_cert filename>
77 a single self signed certificate to be signed by the CA.
79 =item B<-spkac filename>
81 a file containing a single Netscape signed public key and challenge
82 and additional field values to be signed by the CA. See the B<SPKAC FORMAT>
83 section for information on the required format.
87 if present this should be the last option, all subsequent arguments
88 are assumed to the the names of files containing certificate requests.
90 =item B<-out filename>
92 the output file to output certificates to. The default is standard
93 output. The certificate details will also be printed out to this
96 =item B<-outdir directory>
98 the directory to output certificates to. The certificate will be
99 written to a filename consisting of the serial number in hex with
104 the CA certificate file.
106 =item B<-keyfile filename>
108 the private key to sign requests with.
110 =item B<-key password>
112 the password used to encrypt the private key. Since on some
113 systems the command line arguments are visible (e.g. Unix with
114 the 'ps' utility) this option should be used with caution.
118 the key password source. For more information about the format of B<arg>
119 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
123 this prints extra details about the operations being performed.
127 don't output the text form of a certificate to the output file.
129 =item B<-startdate date>
131 this allows the start date to be explicitly set. The format of the
132 date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure).
134 =item B<-enddate date>
136 this allows the expiry date to be explicitly set. The format of the
137 date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure).
141 the number of days to certify the certificate for.
145 the message digest to use. Possible values include md5, sha1 and mdc2.
146 This option also applies to CRLs.
150 this option defines the CA "policy" to use. This is a section in
151 the configuration file which decides which fields should be mandatory
152 or match the CA certificate. Check out the B<POLICY FORMAT> section
153 for more information.
157 this is a legacy option to make B<ca> work with very old versions of
158 the IE certificate enrollment control "certenr3". It used UniversalStrings
159 for almost everything. Since the old control has various security bugs
160 its use is strongly discouraged. The newer control "Xenroll" does not
165 Normally the DN order of a certificate is the same as the order of the
166 fields in the relevant policy section. When this option is set the order
167 is the same as the request. This is largely for compatibility with the
168 older IE enrollment control which would only accept certificates if their
169 DNs match the order of the request. This is not needed for Xenroll.
173 The DN of a certificate can contain the EMAIL field if present in the
174 request DN, however it is good policy just having the e-mail set into
175 the altName extension of the certificate. When this option is set the
176 EMAIL field is removed from the certificate' subject and set only in
177 the, eventually present, extensions. The B<email_in_dn> keyword can be
178 used in the configuration file to enable this behaviour.
182 this sets the batch mode. In this mode no questions will be asked
183 and all certificates will be certified automatically.
185 =item B<-extensions section>
187 the section of the configuration file containing certificate extensions
188 to be added when a certificate is issued (defaults to B<x509_extensions>
189 unless the B<-extfile> option is used). If no extension section is
190 present then, a V1 certificate is created. If the extension section
191 is present (even if it is empty), then a V3 certificate is created.
193 =item B<-extfile file>
195 an additional configuration file to read certificate extensions from
196 (using the default section unless the B<-extensions> option is also
201 specifying an engine (by it's unique B<id> string) will cause B<req>
202 to attempt to obtain a functional reference to the specified engine,
203 thus initialising it if needed. The engine will then be set as the default
204 for all available algorithms.
214 this option generates a CRL based on information in the index file.
216 =item B<-crldays num>
218 the number of days before the next CRL is due. That is the days from
219 now to place in the CRL nextUpdate field.
221 =item B<-crlhours num>
223 the number of hours before the next CRL is due.
225 =item B<-revoke filename>
227 a filename containing a certificate to revoke.
229 =item B<-crl_reason reason>
231 revocation reason, where B<reason> is one of: B<unspecified>, B<keyCompromise>,
232 B<CACompromise>, B<affiliationChanged>, B<superseded>, B<cessationOfOperation>,
233 B<certificateHold> or B<removeFromCRL>. The matching of B<reason> is case
234 insensitive. Setting any revocation reason will make the CRL v2.
236 In practive B<removeFromCRL> is not particularly useful because it is only used
237 in delta CRLs which are not currently implemented.
239 =item B<-crl_hold instruction>
241 This sets the CRL revocation reason code to B<certificateHold> and the hold
242 instruction to B<instruction> which must be an OID. Although any OID can be
243 used only B<holdInstructionNone> (the use of which is discouraged by RFC2459)
244 B<holdInstructionCallIssuer> or B<holdInstructionReject> will normally be used.
246 =item B<-crl_compromise time>
248 This sets the revocation reason to B<keyCompromise> and the compromise time to
249 B<time>. B<time> should be in GeneralizedTime format that is B<YYYYMMDDHHMMSSZ>.
251 =item B<-crl_CA_compromise time>
253 This is the same as B<crl_compromise> except the revocation reason is set to
258 supersedes subject name given in the request.
259 The arg must be formatted as I</type0=value0/type1=value1/type2=...>,
260 characters may be escaped by \ (backslash), no spaces are skipped.
262 =item B<-crlexts section>
264 the section of the configuration file containing CRL extensions to
265 include. If no CRL extension section is present then a V1 CRL is
266 created, if the CRL extension section is present (even if it is
267 empty) then a V2 CRL is created. The CRL extensions specified are
268 CRL extensions and B<not> CRL entry extensions. It should be noted
269 that some software (for example Netscape) can't handle V2 CRLs.
273 =head1 CONFIGURATION FILE OPTIONS
275 The section of the configuration file containing options for B<ca>
276 is found as follows: If the B<-name> command line option is used,
277 then it names the section to be used. Otherwise the section to
278 be used must be named in the B<default_ca> option of the B<ca> section
279 of the configuration file (or in the default section of the
280 configuration file). Besides B<default_ca>, the following options are
281 read directly from the B<ca> section:
285 With the exception of B<RANDFILE>, this is probably a bug and may
286 change in future releases.
288 Many of the configuration file options are identical to command line
289 options. Where the option is present in the configuration file
290 and the command line the command line value is used. Where an
291 option is described as mandatory then it must be present in
292 the configuration file or the command line equivalent (if
299 This specifies a file containing additional B<OBJECT IDENTIFIERS>.
300 Each line of the file should consist of the numerical form of the
301 object identifier followed by white space then the short name followed
302 by white space and finally the long name.
306 This specifies a section in the configuration file containing extra
307 object identifiers. Each line should consist of the short name of the
308 object identifier followed by B<=> and the numerical form. The short
309 and long names are the same when this option is used.
311 =item B<new_certs_dir>
313 the same as the B<-outdir> command line option. It specifies
314 the directory where new certificates will be placed. Mandatory.
318 the same as B<-cert>. It gives the file containing the CA
319 certificate. Mandatory.
323 same as the B<-keyfile> option. The file containing the
324 CA private key. Mandatory.
328 a file used to read and write random number seed information, or
329 an EGD socket (see L<RAND_egd(3)|RAND_egd(3)>).
331 =item B<default_days>
333 the same as the B<-days> option. The number of days to certify
336 =item B<default_startdate>
338 the same as the B<-startdate> option. The start date to certify
339 a certificate for. If not set the current time is used.
341 =item B<default_enddate>
343 the same as the B<-enddate> option. Either this option or
344 B<default_days> (or the command line equivalents) must be
347 =item B<default_crl_hours default_crl_days>
349 the same as the B<-crlhours> and the B<-crldays> options. These
350 will only be used if neither command line option is present. At
351 least one of these must be present to generate a CRL.
355 the same as the B<-md> option. The message digest to use. Mandatory.
359 the text database file to use. Mandatory. This file must be present
360 though initially it will be empty.
364 a text file containing the next serial number to use in hex. Mandatory.
365 This file must be present and contain a valid serial number.
367 =item B<x509_extensions>
369 the same as B<-extensions>.
371 =item B<crl_extensions>
373 the same as B<-crlexts>.
377 the same as B<-preserveDN>
381 the same as B<-noemailDN>. If you want the EMAIL field to be removed
382 from the DN of the certificate simply set this to 'no'. If not present
383 the default is to allow for the EMAIL filed in the certificate's DN.
387 the same as B<-msie_hack>
391 the same as B<-policy>. Mandatory. See the B<POLICY FORMAT> section
392 for more information.
394 =item B<nameopt>, B<certopt>
396 these options allow the format used to display the certificate details
397 when asking the user to confirm signing. All the options supported by
398 the B<x509> utilities B<-nameopt> and B<-certopt> switches can be used
399 here, except the B<no_signame> and B<no_sigdump> are permanently set
400 and cannot be disabled (this is because the certificate signature cannot
401 be displayed because the certificate has not been signed at this point).
403 For convenience the values B<ca_default> are accepted by both to produce
406 If neither option is present the format used in earlier versions of
407 OpenSSL is used. Use of the old format is B<strongly> discouraged because
408 it only displays fields mentioned in the B<policy> section, mishandles
409 multicharacter string types and does not display extensions.
411 =item B<copy_extensions>
413 determines how extensions in certificate requests should be handled.
414 If set to B<none> or this option is not present then extensions are
415 ignored and not copied to the certificate. If set to B<copy> then any
416 extensions present in the request that are not already present are copied
417 to the certificate. If set to B<copyall> then all extensions in the
418 request are copied to the certificate: if the extension is already present
419 in the certificate it is deleted first. See the B<WARNINGS> section before
422 The main use of this option is to allow a certificate request to supply
423 values for certain extensions such as subjectAltName.
429 The policy section consists of a set of variables corresponding to
430 certificate DN fields. If the value is "match" then the field value
431 must match the same field in the CA certificate. If the value is
432 "supplied" then it must be present. If the value is "optional" then
433 it may be present. Any fields not mentioned in the policy section
434 are silently deleted, unless the B<-preserveDN> option is set but
435 this can be regarded more of a quirk than intended behaviour.
439 The input to the B<-spkac> command line option is a Netscape
440 signed public key and challenge. This will usually come from
441 the B<KEYGEN> tag in an HTML form to create a new private key.
442 It is however possible to create SPKACs using the B<spkac> utility.
444 The file should contain the variable SPKAC set to the value of
445 the SPKAC and also the required DN components as name value pairs.
446 If you need to include the same component twice then it can be
447 preceded by a number and a '.'.
451 Note: these examples assume that the B<ca> directory structure is
452 already set up and the relevant files already exist. This usually
453 involves creating a CA certificate and private key with B<req>, a
454 serial number file and an empty index file and placing them in
455 the relevant directories.
457 To use the sample configuration file below the directories demoCA,
458 demoCA/private and demoCA/newcerts would be created. The CA
459 certificate would be copied to demoCA/cacert.pem and its private
460 key to demoCA/private/cakey.pem. A file demoCA/serial would be
461 created containing for example "01" and the empty index file
465 Sign a certificate request:
467 openssl ca -in req.pem -out newcert.pem
469 Sign a certificate request, using CA extensions:
471 openssl ca -in req.pem -extensions v3_ca -out newcert.pem
475 openssl ca -gencrl -out crl.pem
477 Sign several requests:
479 openssl ca -infiles req1.pem req2.pem req3.pem
481 Certify a Netscape SPKAC:
483 openssl ca -spkac spkac.txt
485 A sample SPKAC file (the SPKAC line has been truncated for clarity):
487 SPKAC=MIG0MGAwXDANBgkqhkiG9w0BAQEFAANLADBIAkEAn7PDhCeV/xIxUg8V70YRxK2A5
489 emailAddress=steve@openssl.org
493 A sample configuration file with the relevant sections for B<ca>:
496 default_ca = CA_default # The default ca section
500 dir = ./demoCA # top dir
501 database = $dir/index.txt # index file.
502 new_certs_dir = $dir/newcerts # new certs dir
504 certificate = $dir/cacert.pem # The CA cert
505 serial = $dir/serial # serial no file
506 private_key = $dir/private/cakey.pem# CA private key
507 RANDFILE = $dir/private/.rand # random number file
509 default_days = 365 # how long to certify for
510 default_crl_days= 30 # how long before next CRL
511 default_md = md5 # md to use
513 policy = policy_any # default policy
514 email_in_dn = no # Don't add the email into cert DN
516 nameopt = ca_default # Subject name display option
517 certopt = ca_default # Certificate display option
518 copy_extensions = none # Don't copy extensions from request
521 countryName = supplied
522 stateOrProvinceName = optional
523 organizationName = optional
524 organizationalUnitName = optional
525 commonName = supplied
526 emailAddress = optional
530 Note: the location of all files can change either by compile time options,
531 configuration file entries, environment variables or command line options.
532 The values below reflect the default values.
534 /usr/local/ssl/lib/openssl.cnf - master configuration file
535 ./demoCA - main CA directory
536 ./demoCA/cacert.pem - CA certificate
537 ./demoCA/private/cakey.pem - CA private key
538 ./demoCA/serial - CA serial number file
539 ./demoCA/serial.old - CA serial number backup file
540 ./demoCA/index.txt - CA text database file
541 ./demoCA/index.txt.old - CA text database backup file
542 ./demoCA/certs - certificate output file
543 ./demoCA/.rnd - CA random seed information
545 =head1 ENVIRONMENT VARIABLES
547 B<OPENSSL_CONF> reflects the location of master configuration file it can
548 be overridden by the B<-config> command line option.
552 The text database index file is a critical part of the process and
553 if corrupted it can be difficult to fix. It is theoretically possible
554 to rebuild the index file from all the issued certificates and a current
555 CRL: however there is no option to do this.
557 V2 CRL features like delta CRL support and CRL numbers are not currently
560 Although several requests can be input and handled at once it is only
561 possible to include one SPKAC or self signed certificate.
565 The use of an in memory text database can cause problems when large
566 numbers of certificates are present because, as the name implies
567 the database has to be kept in memory.
569 It is not possible to certify two certificates with the same DN: this
570 is a side effect of how the text database is indexed and it cannot easily
571 be fixed without introducing other problems. Some S/MIME clients can use
572 two certificates with the same DN for separate signing and encryption
575 The B<ca> command really needs rewriting or the required functionality
576 exposed at either a command or interface level so a more friendly utility
577 (perl script or GUI) can handle things properly. The scripts B<CA.sh> and
578 B<CA.pl> help a little but not very much.
580 Any fields in a request that are not present in a policy are silently
581 deleted. This does not happen if the B<-preserveDN> option is used. To
582 enforce the absence of the EMAIL field within the DN, as suggested by
583 RFCs, regardless the contents of the request' subject the B<-noemailDN>
584 option can be used. The behaviour should be more friendly and
587 Cancelling some commands by refusing to certify a certificate can
588 create an empty file.
592 The B<ca> command is quirky and at times downright unfriendly.
594 The B<ca> utility was originally meant as an example of how to do things
595 in a CA. It was not supposed to be used as a full blown CA itself:
596 nevertheless some people are using it for this purpose.
598 The B<ca> command is effectively a single user command: no locking is
599 done on the various files and attempts to run more than one B<ca> command
600 on the same database can have unpredictable results.
602 The B<copy_extensions> option should be used with caution. If care is
603 not taken then it can be a security risk. For example if a certificate
604 request contains a basicConstraints extension with CA:TRUE and the
605 B<copy_extensions> value is set to B<copyall> and the user does not spot
606 this when the certificate is displayed then this will hand the requestor
607 a valid CA certificate.
609 This situation can be avoided by setting B<copy_extensions> to B<copy>
610 and including basicConstraints with CA:FALSE in the configuration file.
611 Then if the request contains a basicConstraints extension it will be
614 It is advisable to also include values for other extensions such
615 as B<keyUsage> to prevent a request supplying its own values.
617 Additional restrictions can be placed on the CA certificate itself.
618 For example if the CA certificate has:
620 basicConstraints = CA:TRUE, pathlen:0
622 then even if a certificate is issued with CA:TRUE it will not be valid.
626 L<req(1)|req(1)>, L<spkac(1)|spkac(1)>, L<x509(1)|x509(1)>, L<CA.pl(1)|CA.pl(1)>,
627 L<config(5)|config(5)>