x509.pod 27 KB

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  1. =pod
  2. =head1 NAME
  3. x509 - Certificate display and signing utility
  4. =head1 SYNOPSIS
  5. B<openssl> B<x509>
  6. [B<-inform DER|PEM|NET>]
  7. [B<-outform DER|PEM|NET>]
  8. [B<-keyform DER|PEM>]
  9. [B<-CAform DER|PEM>]
  10. [B<-CAkeyform DER|PEM>]
  11. [B<-in filename>]
  12. [B<-out filename>]
  13. [B<-serial>]
  14. [B<-hash>]
  15. [B<-subject_hash>]
  16. [B<-issuer_hash>]
  17. [B<-ocspid>]
  18. [B<-subject>]
  19. [B<-issuer>]
  20. [B<-nameopt option>]
  21. [B<-email>]
  22. [B<-ocsp_uri>]
  23. [B<-startdate>]
  24. [B<-enddate>]
  25. [B<-purpose>]
  26. [B<-dates>]
  27. [B<-checkend num>]
  28. [B<-modulus>]
  29. [B<-pubkey>]
  30. [B<-fingerprint>]
  31. [B<-alias>]
  32. [B<-noout>]
  33. [B<-trustout>]
  34. [B<-clrtrust>]
  35. [B<-clrreject>]
  36. [B<-addtrust arg>]
  37. [B<-addreject arg>]
  38. [B<-setalias arg>]
  39. [B<-days arg>]
  40. [B<-set_serial n>]
  41. [B<-signkey filename>]
  42. [B<-passin arg>]
  43. [B<-x509toreq>]
  44. [B<-req>]
  45. [B<-CA filename>]
  46. [B<-CAkey filename>]
  47. [B<-CAcreateserial>]
  48. [B<-CAserial filename>]
  49. [B<-force_pubkey key>]
  50. [B<-text>]
  51. [B<-certopt option>]
  52. [B<-C>]
  53. [B<-md2|-md5|-sha1|-mdc2>]
  54. [B<-clrext>]
  55. [B<-extfile filename>]
  56. [B<-extensions section>]
  57. [B<-engine id>]
  58. =head1 DESCRIPTION
  59. The B<x509> command is a multi purpose certificate utility. It can be
  60. used to display certificate information, convert certificates to
  61. various forms, sign certificate requests like a "mini CA" or edit
  62. certificate trust settings.
  63. Since there are a large number of options they will split up into
  64. various sections.
  65. =head1 OPTIONS
  66. =head2 INPUT, OUTPUT AND GENERAL PURPOSE OPTIONS
  67. =over 4
  68. =item B<-inform DER|PEM|NET>
  69. This specifies the input format normally the command will expect an X509
  70. certificate but this can change if other options such as B<-req> are
  71. present. The DER format is the DER encoding of the certificate and PEM
  72. is the base64 encoding of the DER encoding with header and footer lines
  73. added. The NET option is an obscure Netscape server format that is now
  74. obsolete.
  75. =item B<-outform DER|PEM|NET>
  76. This specifies the output format, the options have the same meaning as the
  77. B<-inform> option.
  78. =item B<-in filename>
  79. This specifies the input filename to read a certificate from or standard input
  80. if this option is not specified.
  81. =item B<-out filename>
  82. This specifies the output filename to write to or standard output by
  83. default.
  84. =item B<-md2|-md5|-sha1|-mdc2>
  85. the digest to use. This affects any signing or display option that uses a message
  86. digest, such as the B<-fingerprint>, B<-signkey> and B<-CA> options. If not
  87. specified then SHA1 is used. If the key being used to sign with is a DSA key
  88. then this option has no effect: SHA1 is always used with DSA keys.
  89. =item B<-engine id>
  90. specifying an engine (by its unique B<id> string) will cause B<x509>
  91. to attempt to obtain a functional reference to the specified engine,
  92. thus initialising it if needed. The engine will then be set as the default
  93. for all available algorithms.
  94. =back
  95. =head2 DISPLAY OPTIONS
  96. Note: the B<-alias> and B<-purpose> options are also display options
  97. but are described in the B<TRUST SETTINGS> section.
  98. =over 4
  99. =item B<-text>
  100. prints out the certificate in text form. Full details are output including the
  101. public key, signature algorithms, issuer and subject names, serial number
  102. any extensions present and any trust settings.
  103. =item B<-certopt option>
  104. customise the output format used with B<-text>. The B<option> argument can be
  105. a single option or multiple options separated by commas. The B<-certopt> switch
  106. may be also be used more than once to set multiple options. See the B<TEXT OPTIONS>
  107. section for more information.
  108. =item B<-noout>
  109. this option prevents output of the encoded version of the request.
  110. =item B<-pubkey>
  111. outputs the the certificate's SubjectPublicKeyInfo block in PEM format.
  112. =item B<-modulus>
  113. this option prints out the value of the modulus of the public key
  114. contained in the certificate.
  115. =item B<-serial>
  116. outputs the certificate serial number.
  117. =item B<-subject_hash>
  118. outputs the "hash" of the certificate subject name. This is used in OpenSSL to
  119. form an index to allow certificates in a directory to be looked up by subject
  120. name.
  121. =item B<-issuer_hash>
  122. outputs the "hash" of the certificate issuer name.
  123. =item B<-ocspid>
  124. outputs the OCSP hash values for the subject name and public key.
  125. =item B<-hash>
  126. synonym for "-subject_hash" for backward compatibility reasons.
  127. =item B<-subject_hash_old>
  128. outputs the "hash" of the certificate subject name using the older algorithm
  129. as used by OpenSSL versions before 1.0.0.
  130. =item B<-issuer_hash_old>
  131. outputs the "hash" of the certificate issuer name using the older algorithm
  132. as used by OpenSSL versions before 1.0.0.
  133. =item B<-subject>
  134. outputs the subject name.
  135. =item B<-issuer>
  136. outputs the issuer name.
  137. =item B<-nameopt option>
  138. option which determines how the subject or issuer names are displayed. The
  139. B<option> argument can be a single option or multiple options separated by
  140. commas. Alternatively the B<-nameopt> switch may be used more than once to
  141. set multiple options. See the B<NAME OPTIONS> section for more information.
  142. =item B<-email>
  143. outputs the email address(es) if any.
  144. =item B<-ocsp_uri>
  145. outputs the OCSP responder address(es) if any.
  146. =item B<-startdate>
  147. prints out the start date of the certificate, that is the notBefore date.
  148. =item B<-enddate>
  149. prints out the expiry date of the certificate, that is the notAfter date.
  150. =item B<-dates>
  151. prints out the start and expiry dates of a certificate.
  152. =item B<-checkend arg>
  153. checks if the certificate expires within the next B<arg> seconds and exits
  154. non-zero if yes it will expire or zero if not.
  155. =item B<-fingerprint>
  156. prints out the digest of the DER encoded version of the whole certificate
  157. (see digest options).
  158. =item B<-C>
  159. this outputs the certificate in the form of a C source file.
  160. =back
  161. =head2 TRUST SETTINGS
  162. Please note these options are currently experimental and may well change.
  163. A B<trusted certificate> is an ordinary certificate which has several
  164. additional pieces of information attached to it such as the permitted
  165. and prohibited uses of the certificate and an "alias".
  166. Normally when a certificate is being verified at least one certificate
  167. must be "trusted". By default a trusted certificate must be stored
  168. locally and must be a root CA: any certificate chain ending in this CA
  169. is then usable for any purpose.
  170. Trust settings currently are only used with a root CA. They allow a finer
  171. control over the purposes the root CA can be used for. For example a CA
  172. may be trusted for SSL client but not SSL server use.
  173. See the description of the B<verify> utility for more information on the
  174. meaning of trust settings.
  175. Future versions of OpenSSL will recognize trust settings on any
  176. certificate: not just root CAs.
  177. =over 4
  178. =item B<-trustout>
  179. this causes B<x509> to output a B<trusted> certificate. An ordinary
  180. or trusted certificate can be input but by default an ordinary
  181. certificate is output and any trust settings are discarded. With the
  182. B<-trustout> option a trusted certificate is output. A trusted
  183. certificate is automatically output if any trust settings are modified.
  184. =item B<-setalias arg>
  185. sets the alias of the certificate. This will allow the certificate
  186. to be referred to using a nickname for example "Steve's Certificate".
  187. =item B<-alias>
  188. outputs the certificate alias, if any.
  189. =item B<-clrtrust>
  190. clears all the permitted or trusted uses of the certificate.
  191. =item B<-clrreject>
  192. clears all the prohibited or rejected uses of the certificate.
  193. =item B<-addtrust arg>
  194. adds a trusted certificate use. Any object name can be used here
  195. but currently only B<clientAuth> (SSL client use), B<serverAuth>
  196. (SSL server use) and B<emailProtection> (S/MIME email) are used.
  197. Other OpenSSL applications may define additional uses.
  198. =item B<-addreject arg>
  199. adds a prohibited use. It accepts the same values as the B<-addtrust>
  200. option.
  201. =item B<-purpose>
  202. this option performs tests on the certificate extensions and outputs
  203. the results. For a more complete description see the B<CERTIFICATE
  204. EXTENSIONS> section.
  205. =back
  206. =head2 SIGNING OPTIONS
  207. The B<x509> utility can be used to sign certificates and requests: it
  208. can thus behave like a "mini CA".
  209. =over 4
  210. =item B<-signkey filename>
  211. this option causes the input file to be self signed using the supplied
  212. private key.
  213. If the input file is a certificate it sets the issuer name to the
  214. subject name (i.e. makes it self signed) changes the public key to the
  215. supplied value and changes the start and end dates. The start date is
  216. set to the current time and the end date is set to a value determined
  217. by the B<-days> option. Any certificate extensions are retained unless
  218. the B<-clrext> option is supplied.
  219. If the input is a certificate request then a self signed certificate
  220. is created using the supplied private key using the subject name in
  221. the request.
  222. =item B<-passin arg>
  223. the key password source. For more information about the format of B<arg>
  224. see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
  225. =item B<-clrext>
  226. delete any extensions from a certificate. This option is used when a
  227. certificate is being created from another certificate (for example with
  228. the B<-signkey> or the B<-CA> options). Normally all extensions are
  229. retained.
  230. =item B<-keyform PEM|DER>
  231. specifies the format (DER or PEM) of the private key file used in the
  232. B<-signkey> option.
  233. =item B<-days arg>
  234. specifies the number of days to make a certificate valid for. The default
  235. is 30 days.
  236. =item B<-x509toreq>
  237. converts a certificate into a certificate request. The B<-signkey> option
  238. is used to pass the required private key.
  239. =item B<-req>
  240. by default a certificate is expected on input. With this option a
  241. certificate request is expected instead.
  242. =item B<-set_serial n>
  243. specifies the serial number to use. This option can be used with either
  244. the B<-signkey> or B<-CA> options. If used in conjunction with the B<-CA>
  245. option the serial number file (as specified by the B<-CAserial> or
  246. B<-CAcreateserial> options) is not used.
  247. The serial number can be decimal or hex (if preceded by B<0x>). Negative
  248. serial numbers can also be specified but their use is not recommended.
  249. =item B<-CA filename>
  250. specifies the CA certificate to be used for signing. When this option is
  251. present B<x509> behaves like a "mini CA". The input file is signed by this
  252. CA using this option: that is its issuer name is set to the subject name
  253. of the CA and it is digitally signed using the CAs private key.
  254. This option is normally combined with the B<-req> option. Without the
  255. B<-req> option the input is a certificate which must be self signed.
  256. =item B<-CAkey filename>
  257. sets the CA private key to sign a certificate with. If this option is
  258. not specified then it is assumed that the CA private key is present in
  259. the CA certificate file.
  260. =item B<-CAserial filename>
  261. sets the CA serial number file to use.
  262. When the B<-CA> option is used to sign a certificate it uses a serial
  263. number specified in a file. This file consist of one line containing
  264. an even number of hex digits with the serial number to use. After each
  265. use the serial number is incremented and written out to the file again.
  266. The default filename consists of the CA certificate file base name with
  267. ".srl" appended. For example if the CA certificate file is called
  268. "mycacert.pem" it expects to find a serial number file called "mycacert.srl".
  269. =item B<-CAcreateserial>
  270. with this option the CA serial number file is created if it does not exist:
  271. it will contain the serial number "02" and the certificate being signed will
  272. have the 1 as its serial number. Normally if the B<-CA> option is specified
  273. and the serial number file does not exist it is an error.
  274. =item B<-extfile filename>
  275. file containing certificate extensions to use. If not specified then
  276. no extensions are added to the certificate.
  277. =item B<-extensions section>
  278. the section to add certificate extensions from. If this option is not
  279. specified then the extensions should either be contained in the unnamed
  280. (default) section or the default section should contain a variable called
  281. "extensions" which contains the section to use. See the
  282. L<x509v3_config(5)|x509v3_config(5)> manual page for details of the
  283. extension section format.
  284. =item B<-force_pubkey key>
  285. when a certificate is created set its public key to B<key> instead of the
  286. key in the certificate or certificate request. This option is useful for
  287. creating certificates where the algorithm can't normally sign requests, for
  288. example DH.
  289. The format or B<key> can be specified using the B<-keyform> option.
  290. =back
  291. =head2 NAME OPTIONS
  292. The B<nameopt> command line switch determines how the subject and issuer
  293. names are displayed. If no B<nameopt> switch is present the default "oneline"
  294. format is used which is compatible with previous versions of OpenSSL.
  295. Each option is described in detail below, all options can be preceded by
  296. a B<-> to turn the option off. Only the first four will normally be used.
  297. =over 4
  298. =item B<compat>
  299. use the old format. This is equivalent to specifying no name options at all.
  300. =item B<RFC2253>
  301. displays names compatible with RFC2253 equivalent to B<esc_2253>, B<esc_ctrl>,
  302. B<esc_msb>, B<utf8>, B<dump_nostr>, B<dump_unknown>, B<dump_der>,
  303. B<sep_comma_plus>, B<dn_rev> and B<sname>.
  304. =item B<oneline>
  305. a oneline format which is more readable than RFC2253. It is equivalent to
  306. specifying the B<esc_2253>, B<esc_ctrl>, B<esc_msb>, B<utf8>, B<dump_nostr>,
  307. B<dump_der>, B<use_quote>, B<sep_comma_plus_space>, B<space_eq> and B<sname>
  308. options.
  309. =item B<multiline>
  310. a multiline format. It is equivalent B<esc_ctrl>, B<esc_msb>, B<sep_multiline>,
  311. B<space_eq>, B<lname> and B<align>.
  312. =item B<esc_2253>
  313. escape the "special" characters required by RFC2253 in a field That is
  314. B<,+"E<lt>E<gt>;>. Additionally B<#> is escaped at the beginning of a string
  315. and a space character at the beginning or end of a string.
  316. =item B<esc_ctrl>
  317. escape control characters. That is those with ASCII values less than
  318. 0x20 (space) and the delete (0x7f) character. They are escaped using the
  319. RFC2253 \XX notation (where XX are two hex digits representing the
  320. character value).
  321. =item B<esc_msb>
  322. escape characters with the MSB set, that is with ASCII values larger than
  323. 127.
  324. =item B<use_quote>
  325. escapes some characters by surrounding the whole string with B<"> characters,
  326. without the option all escaping is done with the B<\> character.
  327. =item B<utf8>
  328. convert all strings to UTF8 format first. This is required by RFC2253. If
  329. you are lucky enough to have a UTF8 compatible terminal then the use
  330. of this option (and B<not> setting B<esc_msb>) may result in the correct
  331. display of multibyte (international) characters. Is this option is not
  332. present then multibyte characters larger than 0xff will be represented
  333. using the format \UXXXX for 16 bits and \WXXXXXXXX for 32 bits.
  334. Also if this option is off any UTF8Strings will be converted to their
  335. character form first.
  336. =item B<ignore_type>
  337. this option does not attempt to interpret multibyte characters in any
  338. way. That is their content octets are merely dumped as though one octet
  339. represents each character. This is useful for diagnostic purposes but
  340. will result in rather odd looking output.
  341. =item B<show_type>
  342. show the type of the ASN1 character string. The type precedes the
  343. field contents. For example "BMPSTRING: Hello World".
  344. =item B<dump_der>
  345. when this option is set any fields that need to be hexdumped will
  346. be dumped using the DER encoding of the field. Otherwise just the
  347. content octets will be displayed. Both options use the RFC2253
  348. B<#XXXX...> format.
  349. =item B<dump_nostr>
  350. dump non character string types (for example OCTET STRING) if this
  351. option is not set then non character string types will be displayed
  352. as though each content octet represents a single character.
  353. =item B<dump_all>
  354. dump all fields. This option when used with B<dump_der> allows the
  355. DER encoding of the structure to be unambiguously determined.
  356. =item B<dump_unknown>
  357. dump any field whose OID is not recognised by OpenSSL.
  358. =item B<sep_comma_plus>, B<sep_comma_plus_space>, B<sep_semi_plus_space>,
  359. B<sep_multiline>
  360. these options determine the field separators. The first character is
  361. between RDNs and the second between multiple AVAs (multiple AVAs are
  362. very rare and their use is discouraged). The options ending in
  363. "space" additionally place a space after the separator to make it
  364. more readable. The B<sep_multiline> uses a linefeed character for
  365. the RDN separator and a spaced B<+> for the AVA separator. It also
  366. indents the fields by four characters. If no field separator is specified
  367. then B<sep_comma_plus_space> is used by default.
  368. =item B<dn_rev>
  369. reverse the fields of the DN. This is required by RFC2253. As a side
  370. effect this also reverses the order of multiple AVAs but this is
  371. permissible.
  372. =item B<nofname>, B<sname>, B<lname>, B<oid>
  373. these options alter how the field name is displayed. B<nofname> does
  374. not display the field at all. B<sname> uses the "short name" form
  375. (CN for commonName for example). B<lname> uses the long form.
  376. B<oid> represents the OID in numerical form and is useful for
  377. diagnostic purpose.
  378. =item B<align>
  379. align field values for a more readable output. Only usable with
  380. B<sep_multiline>.
  381. =item B<space_eq>
  382. places spaces round the B<=> character which follows the field
  383. name.
  384. =back
  385. =head2 TEXT OPTIONS
  386. As well as customising the name output format, it is also possible to
  387. customise the actual fields printed using the B<certopt> options when
  388. the B<text> option is present. The default behaviour is to print all fields.
  389. =over 4
  390. =item B<compatible>
  391. use the old format. This is equivalent to specifying no output options at all.
  392. =item B<no_header>
  393. don't print header information: that is the lines saying "Certificate" and "Data".
  394. =item B<no_version>
  395. don't print out the version number.
  396. =item B<no_serial>
  397. don't print out the serial number.
  398. =item B<no_signame>
  399. don't print out the signature algorithm used.
  400. =item B<no_validity>
  401. don't print the validity, that is the B<notBefore> and B<notAfter> fields.
  402. =item B<no_subject>
  403. don't print out the subject name.
  404. =item B<no_issuer>
  405. don't print out the issuer name.
  406. =item B<no_pubkey>
  407. don't print out the public key.
  408. =item B<no_sigdump>
  409. don't give a hexadecimal dump of the certificate signature.
  410. =item B<no_aux>
  411. don't print out certificate trust information.
  412. =item B<no_extensions>
  413. don't print out any X509V3 extensions.
  414. =item B<ext_default>
  415. retain default extension behaviour: attempt to print out unsupported certificate extensions.
  416. =item B<ext_error>
  417. print an error message for unsupported certificate extensions.
  418. =item B<ext_parse>
  419. ASN1 parse unsupported extensions.
  420. =item B<ext_dump>
  421. hex dump unsupported extensions.
  422. =item B<ca_default>
  423. the value used by the B<ca> utility, equivalent to B<no_issuer>, B<no_pubkey>,
  424. B<no_header>, and B<no_version>.
  425. =back
  426. =head1 EXAMPLES
  427. Note: in these examples the '\' means the example should be all on one
  428. line.
  429. Display the contents of a certificate:
  430. openssl x509 -in cert.pem -noout -text
  431. Display the certificate serial number:
  432. openssl x509 -in cert.pem -noout -serial
  433. Display the certificate subject name:
  434. openssl x509 -in cert.pem -noout -subject
  435. Display the certificate subject name in RFC2253 form:
  436. openssl x509 -in cert.pem -noout -subject -nameopt RFC2253
  437. Display the certificate subject name in oneline form on a terminal
  438. supporting UTF8:
  439. openssl x509 -in cert.pem -noout -subject -nameopt oneline,-esc_msb
  440. Display the certificate MD5 fingerprint:
  441. openssl x509 -in cert.pem -noout -fingerprint
  442. Display the certificate SHA1 fingerprint:
  443. openssl x509 -sha1 -in cert.pem -noout -fingerprint
  444. Convert a certificate from PEM to DER format:
  445. openssl x509 -in cert.pem -inform PEM -out cert.der -outform DER
  446. Convert a certificate to a certificate request:
  447. openssl x509 -x509toreq -in cert.pem -out req.pem -signkey key.pem
  448. Convert a certificate request into a self signed certificate using
  449. extensions for a CA:
  450. openssl x509 -req -in careq.pem -extfile openssl.cnf -extensions v3_ca \
  451. -signkey key.pem -out cacert.pem
  452. Sign a certificate request using the CA certificate above and add user
  453. certificate extensions:
  454. openssl x509 -req -in req.pem -extfile openssl.cnf -extensions v3_usr \
  455. -CA cacert.pem -CAkey key.pem -CAcreateserial
  456. Set a certificate to be trusted for SSL client use and change set its alias to
  457. "Steve's Class 1 CA"
  458. openssl x509 -in cert.pem -addtrust clientAuth \
  459. -setalias "Steve's Class 1 CA" -out trust.pem
  460. =head1 NOTES
  461. The PEM format uses the header and footer lines:
  462. -----BEGIN CERTIFICATE-----
  463. -----END CERTIFICATE-----
  464. it will also handle files containing:
  465. -----BEGIN X509 CERTIFICATE-----
  466. -----END X509 CERTIFICATE-----
  467. Trusted certificates have the lines
  468. -----BEGIN TRUSTED CERTIFICATE-----
  469. -----END TRUSTED CERTIFICATE-----
  470. The conversion to UTF8 format used with the name options assumes that
  471. T61Strings use the ISO8859-1 character set. This is wrong but Netscape
  472. and MSIE do this as do many certificates. So although this is incorrect
  473. it is more likely to display the majority of certificates correctly.
  474. The B<-fingerprint> option takes the digest of the DER encoded certificate.
  475. This is commonly called a "fingerprint". Because of the nature of message
  476. digests the fingerprint of a certificate is unique to that certificate and
  477. two certificates with the same fingerprint can be considered to be the same.
  478. The Netscape fingerprint uses MD5 whereas MSIE uses SHA1.
  479. The B<-email> option searches the subject name and the subject alternative
  480. name extension. Only unique email addresses will be printed out: it will
  481. not print the same address more than once.
  482. =head1 CERTIFICATE EXTENSIONS
  483. The B<-purpose> option checks the certificate extensions and determines
  484. what the certificate can be used for. The actual checks done are rather
  485. complex and include various hacks and workarounds to handle broken
  486. certificates and software.
  487. The same code is used when verifying untrusted certificates in chains
  488. so this section is useful if a chain is rejected by the verify code.
  489. The basicConstraints extension CA flag is used to determine whether the
  490. certificate can be used as a CA. If the CA flag is true then it is a CA,
  491. if the CA flag is false then it is not a CA. B<All> CAs should have the
  492. CA flag set to true.
  493. If the basicConstraints extension is absent then the certificate is
  494. considered to be a "possible CA" other extensions are checked according
  495. to the intended use of the certificate. A warning is given in this case
  496. because the certificate should really not be regarded as a CA: however
  497. it is allowed to be a CA to work around some broken software.
  498. If the certificate is a V1 certificate (and thus has no extensions) and
  499. it is self signed it is also assumed to be a CA but a warning is again
  500. given: this is to work around the problem of Verisign roots which are V1
  501. self signed certificates.
  502. If the keyUsage extension is present then additional restraints are
  503. made on the uses of the certificate. A CA certificate B<must> have the
  504. keyCertSign bit set if the keyUsage extension is present.
  505. The extended key usage extension places additional restrictions on the
  506. certificate uses. If this extension is present (whether critical or not)
  507. the key can only be used for the purposes specified.
  508. A complete description of each test is given below. The comments about
  509. basicConstraints and keyUsage and V1 certificates above apply to B<all>
  510. CA certificates.
  511. =over 4
  512. =item B<SSL Client>
  513. The extended key usage extension must be absent or include the "web client
  514. authentication" OID. keyUsage must be absent or it must have the
  515. digitalSignature bit set. Netscape certificate type must be absent or it must
  516. have the SSL client bit set.
  517. =item B<SSL Client CA>
  518. The extended key usage extension must be absent or include the "web client
  519. authentication" OID. Netscape certificate type must be absent or it must have
  520. the SSL CA bit set: this is used as a work around if the basicConstraints
  521. extension is absent.
  522. =item B<SSL Server>
  523. The extended key usage extension must be absent or include the "web server
  524. authentication" and/or one of the SGC OIDs. keyUsage must be absent or it
  525. must have the digitalSignature, the keyEncipherment set or both bits set.
  526. Netscape certificate type must be absent or have the SSL server bit set.
  527. =item B<SSL Server CA>
  528. The extended key usage extension must be absent or include the "web server
  529. authentication" and/or one of the SGC OIDs. Netscape certificate type must
  530. be absent or the SSL CA bit must be set: this is used as a work around if the
  531. basicConstraints extension is absent.
  532. =item B<Netscape SSL Server>
  533. For Netscape SSL clients to connect to an SSL server it must have the
  534. keyEncipherment bit set if the keyUsage extension is present. This isn't
  535. always valid because some cipher suites use the key for digital signing.
  536. Otherwise it is the same as a normal SSL server.
  537. =item B<Common S/MIME Client Tests>
  538. The extended key usage extension must be absent or include the "email
  539. protection" OID. Netscape certificate type must be absent or should have the
  540. S/MIME bit set. If the S/MIME bit is not set in netscape certificate type
  541. then the SSL client bit is tolerated as an alternative but a warning is shown:
  542. this is because some Verisign certificates don't set the S/MIME bit.
  543. =item B<S/MIME Signing>
  544. In addition to the common S/MIME client tests the digitalSignature bit must
  545. be set if the keyUsage extension is present.
  546. =item B<S/MIME Encryption>
  547. In addition to the common S/MIME tests the keyEncipherment bit must be set
  548. if the keyUsage extension is present.
  549. =item B<S/MIME CA>
  550. The extended key usage extension must be absent or include the "email
  551. protection" OID. Netscape certificate type must be absent or must have the
  552. S/MIME CA bit set: this is used as a work around if the basicConstraints
  553. extension is absent.
  554. =item B<CRL Signing>
  555. The keyUsage extension must be absent or it must have the CRL signing bit
  556. set.
  557. =item B<CRL Signing CA>
  558. The normal CA tests apply. Except in this case the basicConstraints extension
  559. must be present.
  560. =back
  561. =head1 BUGS
  562. Extensions in certificates are not transferred to certificate requests and
  563. vice versa.
  564. It is possible to produce invalid certificates or requests by specifying the
  565. wrong private key or using inconsistent options in some cases: these should
  566. be checked.
  567. There should be options to explicitly set such things as start and end
  568. dates rather than an offset from the current time.
  569. The code to implement the verify behaviour described in the B<TRUST SETTINGS>
  570. is currently being developed. It thus describes the intended behaviour rather
  571. than the current behaviour. It is hoped that it will represent reality in
  572. OpenSSL 0.9.5 and later.
  573. =head1 SEE ALSO
  574. L<req(1)|req(1)>, L<ca(1)|ca(1)>, L<genrsa(1)|genrsa(1)>,
  575. L<gendsa(1)|gendsa(1)>, L<verify(1)|verify(1)>,
  576. L<x509v3_config(5)|x509v3_config(5)>
  577. =head1 HISTORY
  578. Before OpenSSL 0.9.8, the default digest for RSA keys was MD5.
  579. The hash algorithm used in the B<-subject_hash> and B<-issuer_hash> options
  580. before OpenSSL 1.0.0 was based on the deprecated MD5 algorithm and the encoding
  581. of the distinguished name. In OpenSSL 1.0.0 and later it is based on a
  582. canonical version of the DN using SHA1. This means that any directories using
  583. the old form must have their links rebuilt using B<c_rehash> or similar.
  584. =cut