ca.pod 25 KB

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  1. =pod
  2. =head1 NAME
  3. openssl-ca,
  4. ca - sample minimal CA application
  5. =head1 SYNOPSIS
  6. B<openssl> B<ca>
  7. [B<-help>]
  8. [B<-verbose>]
  9. [B<-config filename>]
  10. [B<-name section>]
  11. [B<-gencrl>]
  12. [B<-revoke file>]
  13. [B<-valid file>]
  14. [B<-status serial>]
  15. [B<-updatedb>]
  16. [B<-crl_reason reason>]
  17. [B<-crl_hold instruction>]
  18. [B<-crl_compromise time>]
  19. [B<-crl_CA_compromise time>]
  20. [B<-crldays days>]
  21. [B<-crlhours hours>]
  22. [B<-crlexts section>]
  23. [B<-startdate date>]
  24. [B<-enddate date>]
  25. [B<-days arg>]
  26. [B<-md arg>]
  27. [B<-policy arg>]
  28. [B<-keyfile arg>]
  29. [B<-keyform PEM|DER>]
  30. [B<-key arg>]
  31. [B<-passin arg>]
  32. [B<-cert file>]
  33. [B<-selfsign>]
  34. [B<-in file>]
  35. [B<-out file>]
  36. [B<-notext>]
  37. [B<-outdir dir>]
  38. [B<-infiles>]
  39. [B<-spkac file>]
  40. [B<-ss_cert file>]
  41. [B<-preserveDN>]
  42. [B<-noemailDN>]
  43. [B<-batch>]
  44. [B<-msie_hack>]
  45. [B<-extensions section>]
  46. [B<-extfile section>]
  47. [B<-engine id>]
  48. [B<-subj arg>]
  49. [B<-utf8>]
  50. [B<-create_serial>]
  51. [B<-rand_serial>]
  52. [B<-multivalue-rdn>]
  53. [B<-rand file...>]
  54. [B<-writerand file>]
  55. =head1 DESCRIPTION
  56. The B<ca> command is a minimal CA application. It can be used
  57. to sign certificate requests in a variety of forms and generate
  58. CRLs it also maintains a text database of issued certificates
  59. and their status.
  60. The options descriptions will be divided into each purpose.
  61. =head1 OPTIONS
  62. =over 4
  63. =item B<-help>
  64. Print out a usage message.
  65. =item B<-verbose>
  66. This prints extra details about the operations being performed.
  67. =item B<-config filename>
  68. Specifies the configuration file to use.
  69. Optional; for a description of the default value,
  70. see L<openssl(1)/COMMAND SUMMARY>.
  71. =item B<-name section>
  72. Specifies the configuration file section to use (overrides
  73. B<default_ca> in the B<ca> section).
  74. =item B<-in filename>
  75. An input filename containing a single certificate request to be
  76. signed by the CA.
  77. =item B<-ss_cert filename>
  78. A single self-signed certificate to be signed by the CA.
  79. =item B<-spkac filename>
  80. A file containing a single Netscape signed public key and challenge
  81. and additional field values to be signed by the CA. See the B<SPKAC FORMAT>
  82. section for information on the required input and output format.
  83. =item B<-infiles>
  84. If present this should be the last option, all subsequent arguments
  85. are taken as the names of files containing certificate requests.
  86. =item B<-out filename>
  87. The output file to output certificates to. The default is standard
  88. output. The certificate details will also be printed out to this
  89. file in PEM format (except that B<-spkac> outputs DER format).
  90. =item B<-outdir directory>
  91. The directory to output certificates to. The certificate will be
  92. written to a filename consisting of the serial number in hex with
  93. ".pem" appended.
  94. =item B<-cert>
  95. The CA certificate file.
  96. =item B<-keyfile filename>
  97. The private key to sign requests with.
  98. =item B<-keyform PEM|DER>
  99. The format of the data in the private key file.
  100. The default is PEM.
  101. =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.
  105. =item B<-selfsign>
  106. Indicates the issued certificates are to be signed with the key
  107. the certificate requests were signed with (given with B<-keyfile>).
  108. Certificate requests signed with a different key are ignored. If
  109. B<-spkac>, B<-ss_cert> or B<-gencrl> are given, B<-selfsign> is
  110. ignored.
  111. A consequence of using B<-selfsign> is that the self-signed
  112. certificate appears among the entries in the certificate database
  113. (see the configuration option B<database>), and uses the same
  114. serial number counter as all other certificates sign with the
  115. self-signed certificate.
  116. =item B<-passin arg>
  117. The key password source. For more information about the format of B<arg>
  118. see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
  119. =item B<-notext>
  120. Don't output the text form of a certificate to the output file.
  121. =item B<-startdate date>
  122. This allows the start date to be explicitly set. The format of the
  123. date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure), or
  124. YYYYMMDDHHMMSSZ (the same as an ASN1 GeneralizedTime structure). In
  125. both formats, seconds SS and timezone Z must be present.
  126. =item B<-enddate date>
  127. This allows the expiry date to be explicitly set. The format of the
  128. date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure), or
  129. YYYYMMDDHHMMSSZ (the same as an ASN1 GeneralizedTime structure). In
  130. both formats, seconds SS and timezone Z must be present.
  131. =item B<-days arg>
  132. The number of days to certify the certificate for.
  133. =item B<-md alg>
  134. The message digest to use.
  135. Any digest supported by the OpenSSL B<dgst> command can be used. For signing
  136. algorithms that do not support a digest (i.e. Ed25519 and Ed448) any message
  137. digest that is set is ignored. This option also applies to CRLs.
  138. =item B<-policy arg>
  139. This option defines the CA "policy" to use. This is a section in
  140. the configuration file which decides which fields should be mandatory
  141. or match the CA certificate. Check out the B<POLICY FORMAT> section
  142. for more information.
  143. =item B<-msie_hack>
  144. This is a deprecated option to make B<ca> work with very old versions of
  145. the IE certificate enrollment control "certenr3". It used UniversalStrings
  146. for almost everything. Since the old control has various security bugs
  147. its use is strongly discouraged.
  148. =item B<-preserveDN>
  149. Normally the DN order of a certificate is the same as the order of the
  150. fields in the relevant policy section. When this option is set the order
  151. is the same as the request. This is largely for compatibility with the
  152. older IE enrollment control which would only accept certificates if their
  153. DNs match the order of the request. This is not needed for Xenroll.
  154. =item B<-noemailDN>
  155. The DN of a certificate can contain the EMAIL field if present in the
  156. request DN, however it is good policy just having the e-mail set into
  157. the altName extension of the certificate. When this option is set the
  158. EMAIL field is removed from the certificate' subject and set only in
  159. the, eventually present, extensions. The B<email_in_dn> keyword can be
  160. used in the configuration file to enable this behaviour.
  161. =item B<-batch>
  162. This sets the batch mode. In this mode no questions will be asked
  163. and all certificates will be certified automatically.
  164. =item B<-extensions section>
  165. The section of the configuration file containing certificate extensions
  166. to be added when a certificate is issued (defaults to B<x509_extensions>
  167. unless the B<-extfile> option is used). If no extension section is
  168. present then, a V1 certificate is created. If the extension section
  169. is present (even if it is empty), then a V3 certificate is created. See the
  170. L<x509v3_config(5)> manual page for details of the
  171. extension section format.
  172. =item B<-extfile file>
  173. An additional configuration file to read certificate extensions from
  174. (using the default section unless the B<-extensions> option is also
  175. used).
  176. =item B<-engine id>
  177. Specifying an engine (by its unique B<id> string) will cause B<ca>
  178. to attempt to obtain a functional reference to the specified engine,
  179. thus initialising it if needed. The engine will then be set as the default
  180. for all available algorithms.
  181. =item B<-subj arg>
  182. Supersedes subject name given in the request.
  183. The arg must be formatted as I</type0=value0/type1=value1/type2=...>.
  184. Keyword characters may be escaped by \ (backslash), and whitespace is retained.
  185. Empty values are permitted, but the corresponding type will not be included
  186. in the resulting certificate.
  187. =item B<-utf8>
  188. This option causes field values to be interpreted as UTF8 strings, by
  189. default they are interpreted as ASCII. This means that the field
  190. values, whether prompted from a terminal or obtained from a
  191. configuration file, must be valid UTF8 strings.
  192. =item B<-create_serial>
  193. If reading serial from the text file as specified in the configuration
  194. fails, specifying this option creates a new random serial to be used as next
  195. serial number.
  196. To get random serial numbers, use the B<-rand_serial> flag instead; this
  197. should only be used for simple error-recovery.
  198. =item B<-rand_serial>
  199. Generate a large random number to use as the serial number.
  200. This overrides any option or configuration to use a serial number file.
  201. =item B<-multivalue-rdn>
  202. This option causes the -subj argument to be interpreted with full
  203. support for multivalued RDNs. Example:
  204. I</DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe>
  205. If -multi-rdn is not used then the UID value is I<123456+CN=John Doe>.
  206. =item B<-rand file...>
  207. A file or files containing random data used to seed the random number
  208. generator.
  209. Multiple files can be specified separated by an OS-dependent character.
  210. The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
  211. all others.
  212. =item [B<-writerand file>]
  213. Writes random data to the specified I<file> upon exit.
  214. This can be used with a subsequent B<-rand> flag.
  215. =back
  216. =head1 CRL OPTIONS
  217. =over 4
  218. =item B<-gencrl>
  219. This option generates a CRL based on information in the index file.
  220. =item B<-crldays num>
  221. The number of days before the next CRL is due. That is the days from
  222. now to place in the CRL nextUpdate field.
  223. =item B<-crlhours num>
  224. The number of hours before the next CRL is due.
  225. =item B<-revoke filename>
  226. A filename containing a certificate to revoke.
  227. =item B<-valid filename>
  228. A filename containing a certificate to add a Valid certificate entry.
  229. =item B<-status serial>
  230. Displays the revocation status of the certificate with the specified
  231. serial number and exits.
  232. =item B<-updatedb>
  233. Updates the database index to purge expired certificates.
  234. =item B<-crl_reason reason>
  235. Revocation reason, where B<reason> is one of: B<unspecified>, B<keyCompromise>,
  236. B<CACompromise>, B<affiliationChanged>, B<superseded>, B<cessationOfOperation>,
  237. B<certificateHold> or B<removeFromCRL>. The matching of B<reason> is case
  238. insensitive. Setting any revocation reason will make the CRL v2.
  239. In practice B<removeFromCRL> is not particularly useful because it is only used
  240. in delta CRLs which are not currently implemented.
  241. =item B<-crl_hold instruction>
  242. This sets the CRL revocation reason code to B<certificateHold> and the hold
  243. instruction to B<instruction> which must be an OID. Although any OID can be
  244. used only B<holdInstructionNone> (the use of which is discouraged by RFC2459)
  245. B<holdInstructionCallIssuer> or B<holdInstructionReject> will normally be used.
  246. =item B<-crl_compromise time>
  247. This sets the revocation reason to B<keyCompromise> and the compromise time to
  248. B<time>. B<time> should be in GeneralizedTime format that is B<YYYYMMDDHHMMSSZ>.
  249. =item B<-crl_CA_compromise time>
  250. This is the same as B<crl_compromise> except the revocation reason is set to
  251. B<CACompromise>.
  252. =item B<-crlexts section>
  253. The section of the configuration file containing CRL extensions to
  254. include. If no CRL extension section is present then a V1 CRL is
  255. created, if the CRL extension section is present (even if it is
  256. empty) then a V2 CRL is created. The CRL extensions specified are
  257. CRL extensions and B<not> CRL entry extensions. It should be noted
  258. that some software (for example Netscape) can't handle V2 CRLs. See
  259. L<x509v3_config(5)> manual page for details of the
  260. extension section format.
  261. =back
  262. =head1 CONFIGURATION FILE OPTIONS
  263. The section of the configuration file containing options for B<ca>
  264. is found as follows: If the B<-name> command line option is used,
  265. then it names the section to be used. Otherwise the section to
  266. be used must be named in the B<default_ca> option of the B<ca> section
  267. of the configuration file (or in the default section of the
  268. configuration file). Besides B<default_ca>, the following options are
  269. read directly from the B<ca> section:
  270. RANDFILE
  271. preserve
  272. msie_hack
  273. With the exception of B<RANDFILE>, this is probably a bug and may
  274. change in future releases.
  275. Many of the configuration file options are identical to command line
  276. options. Where the option is present in the configuration file
  277. and the command line the command line value is used. Where an
  278. option is described as mandatory then it must be present in
  279. the configuration file or the command line equivalent (if
  280. any) used.
  281. =over 4
  282. =item B<oid_file>
  283. This specifies a file containing additional B<OBJECT IDENTIFIERS>.
  284. Each line of the file should consist of the numerical form of the
  285. object identifier followed by white space then the short name followed
  286. by white space and finally the long name.
  287. =item B<oid_section>
  288. This specifies a section in the configuration file containing extra
  289. object identifiers. Each line should consist of the short name of the
  290. object identifier followed by B<=> and the numerical form. The short
  291. and long names are the same when this option is used.
  292. =item B<new_certs_dir>
  293. The same as the B<-outdir> command line option. It specifies
  294. the directory where new certificates will be placed. Mandatory.
  295. =item B<certificate>
  296. The same as B<-cert>. It gives the file containing the CA
  297. certificate. Mandatory.
  298. =item B<private_key>
  299. Same as the B<-keyfile> option. The file containing the
  300. CA private key. Mandatory.
  301. =item B<RANDFILE>
  302. At startup the specified file is loaded into the random number generator,
  303. and at exit 256 bytes will be written to it.
  304. =item B<default_days>
  305. The same as the B<-days> option. The number of days to certify
  306. a certificate for.
  307. =item B<default_startdate>
  308. The same as the B<-startdate> option. The start date to certify
  309. a certificate for. If not set the current time is used.
  310. =item B<default_enddate>
  311. The same as the B<-enddate> option. Either this option or
  312. B<default_days> (or the command line equivalents) must be
  313. present.
  314. =item B<default_crl_hours default_crl_days>
  315. The same as the B<-crlhours> and the B<-crldays> options. These
  316. will only be used if neither command line option is present. At
  317. least one of these must be present to generate a CRL.
  318. =item B<default_md>
  319. The same as the B<-md> option. Mandatory except where the signing algorithm does
  320. not require a digest (i.e. Ed25519 and Ed448).
  321. =item B<database>
  322. The text database file to use. Mandatory. This file must be present
  323. though initially it will be empty.
  324. =item B<unique_subject>
  325. If the value B<yes> is given, the valid certificate entries in the
  326. database must have unique subjects. if the value B<no> is given,
  327. several valid certificate entries may have the exact same subject.
  328. The default value is B<yes>, to be compatible with older (pre 0.9.8)
  329. versions of OpenSSL. However, to make CA certificate roll-over easier,
  330. it's recommended to use the value B<no>, especially if combined with
  331. the B<-selfsign> command line option.
  332. Note that it is valid in some circumstances for certificates to be created
  333. without any subject. In the case where there are multiple certificates without
  334. subjects this does not count as a duplicate.
  335. =item B<serial>
  336. A text file containing the next serial number to use in hex. Mandatory.
  337. This file must be present and contain a valid serial number.
  338. =item B<crlnumber>
  339. A text file containing the next CRL number to use in hex. The crl number
  340. will be inserted in the CRLs only if this file exists. If this file is
  341. present, it must contain a valid CRL number.
  342. =item B<x509_extensions>
  343. The same as B<-extensions>.
  344. =item B<crl_extensions>
  345. The same as B<-crlexts>.
  346. =item B<preserve>
  347. The same as B<-preserveDN>
  348. =item B<email_in_dn>
  349. The same as B<-noemailDN>. If you want the EMAIL field to be removed
  350. from the DN of the certificate simply set this to 'no'. If not present
  351. the default is to allow for the EMAIL filed in the certificate's DN.
  352. =item B<msie_hack>
  353. The same as B<-msie_hack>
  354. =item B<policy>
  355. The same as B<-policy>. Mandatory. See the B<POLICY FORMAT> section
  356. for more information.
  357. =item B<name_opt>, B<cert_opt>
  358. These options allow the format used to display the certificate details
  359. when asking the user to confirm signing. All the options supported by
  360. the B<x509> utilities B<-nameopt> and B<-certopt> switches can be used
  361. here, except the B<no_signame> and B<no_sigdump> are permanently set
  362. and cannot be disabled (this is because the certificate signature cannot
  363. be displayed because the certificate has not been signed at this point).
  364. For convenience the values B<ca_default> are accepted by both to produce
  365. a reasonable output.
  366. If neither option is present the format used in earlier versions of
  367. OpenSSL is used. Use of the old format is B<strongly> discouraged because
  368. it only displays fields mentioned in the B<policy> section, mishandles
  369. multicharacter string types and does not display extensions.
  370. =item B<copy_extensions>
  371. Determines how extensions in certificate requests should be handled.
  372. If set to B<none> or this option is not present then extensions are
  373. ignored and not copied to the certificate. If set to B<copy> then any
  374. extensions present in the request that are not already present are copied
  375. to the certificate. If set to B<copyall> then all extensions in the
  376. request are copied to the certificate: if the extension is already present
  377. in the certificate it is deleted first. See the B<WARNINGS> section before
  378. using this option.
  379. The main use of this option is to allow a certificate request to supply
  380. values for certain extensions such as subjectAltName.
  381. =back
  382. =head1 POLICY FORMAT
  383. The policy section consists of a set of variables corresponding to
  384. certificate DN fields. If the value is "match" then the field value
  385. must match the same field in the CA certificate. If the value is
  386. "supplied" then it must be present. If the value is "optional" then
  387. it may be present. Any fields not mentioned in the policy section
  388. are silently deleted, unless the B<-preserveDN> option is set but
  389. this can be regarded more of a quirk than intended behaviour.
  390. =head1 SPKAC FORMAT
  391. The input to the B<-spkac> command line option is a Netscape
  392. signed public key and challenge. This will usually come from
  393. the B<KEYGEN> tag in an HTML form to create a new private key.
  394. It is however possible to create SPKACs using the B<spkac> utility.
  395. The file should contain the variable SPKAC set to the value of
  396. the SPKAC and also the required DN components as name value pairs.
  397. If you need to include the same component twice then it can be
  398. preceded by a number and a '.'.
  399. When processing SPKAC format, the output is DER if the B<-out>
  400. flag is used, but PEM format if sending to stdout or the B<-outdir>
  401. flag is used.
  402. =head1 EXAMPLES
  403. Note: these examples assume that the B<ca> directory structure is
  404. already set up and the relevant files already exist. This usually
  405. involves creating a CA certificate and private key with B<req>, a
  406. serial number file and an empty index file and placing them in
  407. the relevant directories.
  408. To use the sample configuration file below the directories demoCA,
  409. demoCA/private and demoCA/newcerts would be created. The CA
  410. certificate would be copied to demoCA/cacert.pem and its private
  411. key to demoCA/private/cakey.pem. A file demoCA/serial would be
  412. created containing for example "01" and the empty index file
  413. demoCA/index.txt.
  414. Sign a certificate request:
  415. openssl ca -in req.pem -out newcert.pem
  416. Sign a certificate request, using CA extensions:
  417. openssl ca -in req.pem -extensions v3_ca -out newcert.pem
  418. Generate a CRL
  419. openssl ca -gencrl -out crl.pem
  420. Sign several requests:
  421. openssl ca -infiles req1.pem req2.pem req3.pem
  422. Certify a Netscape SPKAC:
  423. openssl ca -spkac spkac.txt
  424. A sample SPKAC file (the SPKAC line has been truncated for clarity):
  425. SPKAC=MIG0MGAwXDANBgkqhkiG9w0BAQEFAANLADBIAkEAn7PDhCeV/xIxUg8V70YRxK2A5
  426. CN=Steve Test
  427. emailAddress=steve@openssl.org
  428. 0.OU=OpenSSL Group
  429. 1.OU=Another Group
  430. A sample configuration file with the relevant sections for B<ca>:
  431. [ ca ]
  432. default_ca = CA_default # The default ca section
  433. [ CA_default ]
  434. dir = ./demoCA # top dir
  435. database = $dir/index.txt # index file.
  436. new_certs_dir = $dir/newcerts # new certs dir
  437. certificate = $dir/cacert.pem # The CA cert
  438. serial = $dir/serial # serial no file
  439. #rand_serial = yes # for random serial#'s
  440. private_key = $dir/private/cakey.pem# CA private key
  441. RANDFILE = $dir/private/.rand # random number file
  442. default_days = 365 # how long to certify for
  443. default_crl_days= 30 # how long before next CRL
  444. default_md = md5 # md to use
  445. policy = policy_any # default policy
  446. email_in_dn = no # Don't add the email into cert DN
  447. name_opt = ca_default # Subject name display option
  448. cert_opt = ca_default # Certificate display option
  449. copy_extensions = none # Don't copy extensions from request
  450. [ policy_any ]
  451. countryName = supplied
  452. stateOrProvinceName = optional
  453. organizationName = optional
  454. organizationalUnitName = optional
  455. commonName = supplied
  456. emailAddress = optional
  457. =head1 FILES
  458. Note: the location of all files can change either by compile time options,
  459. configuration file entries, environment variables or command line options.
  460. The values below reflect the default values.
  461. /usr/local/ssl/lib/openssl.cnf - master configuration file
  462. ./demoCA - main CA directory
  463. ./demoCA/cacert.pem - CA certificate
  464. ./demoCA/private/cakey.pem - CA private key
  465. ./demoCA/serial - CA serial number file
  466. ./demoCA/serial.old - CA serial number backup file
  467. ./demoCA/index.txt - CA text database file
  468. ./demoCA/index.txt.old - CA text database backup file
  469. ./demoCA/certs - certificate output file
  470. ./demoCA/.rnd - CA random seed information
  471. =head1 RESTRICTIONS
  472. The text database index file is a critical part of the process and
  473. if corrupted it can be difficult to fix. It is theoretically possible
  474. to rebuild the index file from all the issued certificates and a current
  475. CRL: however there is no option to do this.
  476. V2 CRL features like delta CRLs are not currently supported.
  477. Although several requests can be input and handled at once it is only
  478. possible to include one SPKAC or self-signed certificate.
  479. =head1 BUGS
  480. The use of an in-memory text database can cause problems when large
  481. numbers of certificates are present because, as the name implies
  482. the database has to be kept in memory.
  483. The B<ca> command really needs rewriting or the required functionality
  484. exposed at either a command or interface level so a more friendly utility
  485. (perl script or GUI) can handle things properly. The script
  486. B<CA.pl> helps a little but not very much.
  487. Any fields in a request that are not present in a policy are silently
  488. deleted. This does not happen if the B<-preserveDN> option is used. To
  489. enforce the absence of the EMAIL field within the DN, as suggested by
  490. RFCs, regardless the contents of the request' subject the B<-noemailDN>
  491. option can be used. The behaviour should be more friendly and
  492. configurable.
  493. Canceling some commands by refusing to certify a certificate can
  494. create an empty file.
  495. =head1 WARNINGS
  496. The B<ca> command is quirky and at times downright unfriendly.
  497. The B<ca> utility was originally meant as an example of how to do things
  498. in a CA. It was not supposed to be used as a full blown CA itself:
  499. nevertheless some people are using it for this purpose.
  500. The B<ca> command is effectively a single user command: no locking is
  501. done on the various files and attempts to run more than one B<ca> command
  502. on the same database can have unpredictable results.
  503. The B<copy_extensions> option should be used with caution. If care is
  504. not taken then it can be a security risk. For example if a certificate
  505. request contains a basicConstraints extension with CA:TRUE and the
  506. B<copy_extensions> value is set to B<copyall> and the user does not spot
  507. this when the certificate is displayed then this will hand the requester
  508. a valid CA certificate.
  509. This situation can be avoided by setting B<copy_extensions> to B<copy>
  510. and including basicConstraints with CA:FALSE in the configuration file.
  511. Then if the request contains a basicConstraints extension it will be
  512. ignored.
  513. It is advisable to also include values for other extensions such
  514. as B<keyUsage> to prevent a request supplying its own values.
  515. Additional restrictions can be placed on the CA certificate itself.
  516. For example if the CA certificate has:
  517. basicConstraints = CA:TRUE, pathlen:0
  518. then even if a certificate is issued with CA:TRUE it will not be valid.
  519. =head1 HISTORY
  520. Since OpenSSL 1.1.1, the program follows RFC5280. Specifically,
  521. certificate validity period (specified by any of B<-startdate>,
  522. B<-enddate> and B<-days>) will be encoded as UTCTime if the dates are
  523. earlier than year 2049 (included), and as GeneralizedTime if the dates
  524. are in year 2050 or later.
  525. =head1 SEE ALSO
  526. L<req(1)>, L<spkac(1)>, L<x509(1)>, L<CA.pl(1)>,
  527. L<config(5)>, L<x509v3_config(5)>
  528. =head1 COPYRIGHT
  529. Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.
  530. Licensed under the Apache License 2.0 (the "License"). You may not use
  531. this file except in compliance with the License. You can obtain a copy
  532. in the file LICENSE in the source distribution or at
  533. L<https://www.openssl.org/source/license.html>.
  534. =cut