1X509(1) OpenSSL X509(1)
2
6 x509 - Certificate display and signing utility
7
9 openssl x509 [-inform DER|PEM|NET] [-outform DER|PEM|NET] [-keyform
10 DER|PEM] [-CAform DER|PEM] [-CAkeyform DER|PEM] [-in filename] [-out
11 filename] [-serial] [-hash] [-subject_hash] [-issuer_hash] [-subject]
12 [-issuer] [-nameopt option] [-email] [-ocsp_uri] [-startdate]
13 [-enddate] [-purpose] [-dates] [-modulus] [-pubkey] [-fingerprint]
14 [-alias] [-noout] [-trustout] [-clrtrust] [-clrreject] [-addtrust arg]
15 [-addreject arg] [-setalias arg] [-days arg] [-set_serial n] [-signkey
16 filename] [-x509toreq] [-req] [-CA filename] [-CAkey filename]
17 [-CAcreateserial] [-CAserial filename] [-text] [-C]
18 [-md2|-md5|-sha1|-mdc2] [-clrext] [-extfile filename] [-extensions
19 section] [-engine id]
20
22 The x509 command is a multi purpose certificate utility. It can be used
23 to display certificate information, convert certificates to various
24 forms, sign certificate requests like a "mini CA" or edit certificate
25 trust settings.
26 Since there are a large number of options they will split up into
28 various sections.
29
31 INPUT, OUTPUT AND GENERAL PURPOSE OPTIONS
32 -inform DER|PEM|NET
33 This specifies the input format normally the command will expect an
34 X509 certificate but this can change if other options such as -req
35 are present. The DER format is the DER encoding of the certificate
36 and PEM is the base64 encoding of the DER encoding with header and
37 footer lines added. The NET option is an obscure Netscape server
38 format that is now obsolete.
39 -outform DER|PEM|NET
41 This specifies the output format, the options have the same meaning
42 as the -inform option.
43 -in filename
45 This specifies the input filename to read a certificate from or
46 standard input if this option is not specified.
47 -out filename
49 This specifies the output filename to write to or standard output
50 by default.
51 -md2|-md5|-sha1|-mdc2
53 the digest to use. This affects any signing or display option that
54 uses a message digest, such as the -fingerprint, -signkey and -CA
55 options. If not specified then SHA1 is used. If the key being used
56 to sign with is a DSA key then this option has no effect: SHA1 is
57 always used with DSA keys. For full list of digests see openssl
58 dgst -h output.
59 -engine id
61 specifying an engine (by its unique id string) will cause x509 to
62 attempt to obtain a functional reference to the specified engine,
63 thus initialising it if needed. The engine will then be set as the
64 default for all available algorithms.
65 DISPLAY OPTIONS
67 Note: the -alias and -purpose options are also display options but are
68 described in the TRUST SETTINGS section.
69 -text
71 prints out the certificate in text form. Full details are output
72 including the public key, signature algorithms, issuer and subject
73 names, serial number any extensions present and any trust settings.
74 -certopt option
76 customise the output format used with -text. The option argument
77 can be a single option or multiple options separated by commas. The
78 -certopt switch may be also be used more than once to set multiple
79 options. See the TEXT OPTIONS section for more information.
80 -noout
82 this option prevents output of the encoded version of the request.
83 -pubkey
85 outputs the the certificate's SubjectPublicKeyInfo block in PEM
86 format.
87 -modulus
89 this option prints out the value of the modulus of the public key
90 contained in the certificate.
91 -serial
93 outputs the certificate serial number.
94 -subject_hash
96 outputs the "hash" of the certificate subject name. This is used in
97 OpenSSL to form an index to allow certificates in a directory to be
98 looked up by subject name.
99 -issuer_hash
101 outputs the "hash" of the certificate issuer name.
102 -hash
104 synonym for "-subject_hash" for backward compatibility reasons.
105 -subject_hash_old
107 outputs the "hash" of the certificate subject name using the older
108 algorithm as used by OpenSSL versions before 1.0.0.
109 -issuer_hash_old
111 outputs the "hash" of the certificate issuer name using the older
112 algorithm as used by OpenSSL versions before 1.0.0.
113 -subject
115 outputs the subject name.
116 -issuer
118 outputs the issuer name.
119 -nameopt option
121 option which determines how the subject or issuer names are
122 displayed. The option argument can be a single option or multiple
123 options separated by commas. Alternatively the -nameopt switch may
124 be used more than once to set multiple options. See the NAME
125 OPTIONS section for more information.
126 -email
128 outputs the email address(es) if any.
129 -ocsp_uri
131 outputs the OCSP responder address(es) if any.
132 -startdate
134 prints out the start date of the certificate, that is the notBefore
135 date.
136 -enddate
138 prints out the expiry date of the certificate, that is the notAfter
139 date.
140 -dates
142 prints out the start and expiry dates of a certificate.
143 -fingerprint
145 prints out the digest of the DER encoded version of the whole
146 certificate (see digest options).
147 -C this outputs the certificate in the form of a C source file.
149 TRUST SETTINGS
151 Please note these options are currently experimental and may well
152 change.
153 A trusted certificate is an ordinary certificate which has several
155 additional pieces of information attached to it such as the permitted
156 and prohibited uses of the certificate and an "alias".
157 Normally when a certificate is being verified at least one certificate
159 must be "trusted". By default a trusted certificate must be stored
160 locally and must be a root CA: any certificate chain ending in this CA
161 is then usable for any purpose.
162 Trust settings currently are only used with a root CA. They allow a
164 finer control over the purposes the root CA can be used for. For
165 example a CA may be trusted for SSL client but not SSL server use.
166 See the description of the verify utility for more information on the
168 meaning of trust settings.
169 Future versions of OpenSSL will recognize trust settings on any
171 certificate: not just root CAs.
172 -trustout
174 this causes x509 to output a trusted certificate. An ordinary or
175 trusted certificate can be input but by default an ordinary
176 certificate is output and any trust settings are discarded. With
177 the -trustout option a trusted certificate is output. A trusted
178 certificate is automatically output if any trust settings are
179 modified.
180 -setalias arg
182 sets the alias of the certificate. This will allow the certificate
183 to be referred to using a nickname for example "Steve's
184 Certificate".
185 -alias
187 outputs the certificate alias, if any.
188 -clrtrust
190 clears all the permitted or trusted uses of the certificate.
191 -clrreject
193 clears all the prohibited or rejected uses of the certificate.
194 -addtrust arg
196 adds a trusted certificate use. Any object name can be used here
197 but currently only clientAuth (SSL client use), serverAuth (SSL
198 server use) and emailProtection (S/MIME email) are used. Other
199 OpenSSL applications may define additional uses.
200 -addreject arg
202 adds a prohibited use. It accepts the same values as the -addtrust
203 option.
204 -purpose
206 this option performs tests on the certificate extensions and
207 outputs the results. For a more complete description see the
208 CERTIFICATE EXTENSIONS section.
209 SIGNING OPTIONS
211 The x509 utility can be used to sign certificates and requests: it can
212 thus behave like a "mini CA".
213 -signkey filename
215 this option causes the input file to be self signed using the
216 supplied private key.
217 If the input file is a certificate it sets the issuer name to the
219 subject name (i.e. makes it self signed) changes the public key to
220 the supplied value and changes the start and end dates. The start
221 date is set to the current time and the end date is set to a value
222 determined by the -days option. Any certificate extensions are
223 retained unless the -clrext option is supplied.
224 If the input is a certificate request then a self signed
226 certificate is created using the supplied private key using the
227 subject name in the request.
228 -clrext
230 delete any extensions from a certificate. This option is used when
231 a certificate is being created from another certificate (for
232 example with the -signkey or the -CA options). Normally all
233 extensions are retained.
234 -keyform PEM|DER
236 specifies the format (DER or PEM) of the private key file used in
237 the -signkey option.
238 -days arg
240 specifies the number of days to make a certificate valid for. The
241 default is 30 days.
242 -x509toreq
244 converts a certificate into a certificate request. The -signkey
245 option is used to pass the required private key.
246 -req
248 by default a certificate is expected on input. With this option a
249 certificate request is expected instead.
250 -set_serial n
252 specifies the serial number to use. This option can be used with
253 either the -signkey or -CA options. If used in conjunction with the
254 -CA option the serial number file (as specified by the -CAserial or
255 -CAcreateserial options) is not used.
256 The serial number can be decimal or hex (if preceded by 0x).
258 Negative serial numbers can also be specified but their use is not
259 recommended.
260 -CA filename
262 specifies the CA certificate to be used for signing. When this
263 option is present x509 behaves like a "mini CA". The input file is
264 signed by this CA using this option: that is its issuer name is set
265 to the subject name of the CA and it is digitally signed using the
266 CAs private key.
267 This option is normally combined with the -req option. Without the
269 -req option the input is a certificate which must be self signed.
270 -CAkey filename
272 sets the CA private key to sign a certificate with. If this option
273 is not specified then it is assumed that the CA private key is
274 present in the CA certificate file.
275 -CAserial filename
277 sets the CA serial number file to use.
278 When the -CA option is used to sign a certificate it uses a serial
280 number specified in a file. This file consist of one line
281 containing an even number of hex digits with the serial number to
282 use. After each use the serial number is incremented and written
283 out to the file again.
284 The default filename consists of the CA certificate file base name
286 with ".srl" appended. For example if the CA certificate file is
287 called "mycacert.pem" it expects to find a serial number file
288 called "mycacert.srl".
289 -CAcreateserial
291 with this option the CA serial number file is created if it does
292 not exist: it will contain the serial number "02" and the
293 certificate being signed will have the 1 as its serial number.
294 Normally if the -CA option is specified and the serial number file
295 does not exist it is an error.
296 -extfile filename
298 file containing certificate extensions to use. If not specified
299 then no extensions are added to the certificate.
300 -extensions section
302 the section to add certificate extensions from. If this option is
303 not specified then the extensions should either be contained in the
304 unnamed (default) section or the default section should contain a
305 variable called "extensions" which contains the section to use. See
306 the x509v3_config(5) manual page for details of the extension
307 section format.
308 NAME OPTIONS
310 The nameopt command line switch determines how the subject and issuer
311 names are displayed. If no nameopt switch is present the default
312 "oneline" format is used which is compatible with previous versions of
313 OpenSSL. Each option is described in detail below, all options can be
314 preceded by a - to turn the option off. Only the first four will
315 normally be used.
316 compat
318 use the old format. This is equivalent to specifying no name
319 options at all.
320 RFC2253
322 displays names compatible with RFC2253 equivalent to esc_2253,
323 esc_ctrl, esc_msb, utf8, dump_nostr, dump_unknown, dump_der,
324 sep_comma_plus, dn_rev and sname.
325 oneline
327 a oneline format which is more readable than RFC2253. It is
328 equivalent to specifying the esc_2253, esc_ctrl, esc_msb, utf8,
329 dump_nostr, dump_der, use_quote, sep_comma_plus_space, space_eq and
330 sname options.
331 multiline
333 a multiline format. It is equivalent esc_ctrl, esc_msb,
334 sep_multiline, space_eq, lname and align.
335 esc_2253
337 escape the "special" characters required by RFC2253 in a field That
338 is ,+"<>;. Additionally # is escaped at the beginning of a string
339 and a space character at the beginning or end of a string.
340 esc_ctrl
342 escape control characters. That is those with ASCII values less
343 than 0x20 (space) and the delete (0x7f) character. They are escaped
344 using the RFC2253 \XX notation (where XX are two hex digits
345 representing the character value).
346 esc_msb
348 escape characters with the MSB set, that is with ASCII values
349 larger than 127.
350 use_quote
352 escapes some characters by surrounding the whole string with "
353 characters, without the option all escaping is done with the \
354 character.
355 utf8
357 convert all strings to UTF8 format first. This is required by
358 RFC2253. If you are lucky enough to have a UTF8 compatible terminal
359 then the use of this option (and not setting esc_msb) may result in
360 the correct display of multibyte (international) characters. Is
361 this option is not present then multibyte characters larger than
362 0xff will be represented using the format \UXXXX for 16 bits and
363 \WXXXXXXXX for 32 bits. Also if this option is off any UTF8Strings
364 will be converted to their character form first.
365 no_type
367 this option does not attempt to interpret multibyte characters in
368 any way. That is their content octets are merely dumped as though
369 one octet represents each character. This is useful for diagnostic
370 purposes but will result in rather odd looking output.
371 show_type
373 show the type of the ASN1 character string. The type precedes the
374 field contents. For example "BMPSTRING: Hello World".
375 dump_der
377 when this option is set any fields that need to be hexdumped will
378 be dumped using the DER encoding of the field. Otherwise just the
379 content octets will be displayed. Both options use the RFC2253
380 #XXXX... format.
381 dump_nostr
383 dump non character string types (for example OCTET STRING) if this
384 option is not set then non character string types will be displayed
385 as though each content octet represents a single character.
386 dump_all
388 dump all fields. This option when used with dump_der allows the DER
389 encoding of the structure to be unambiguously determined.
390 dump_unknown
392 dump any field whose OID is not recognised by OpenSSL.
393 sep_comma_plus, sep_comma_plus_space, sep_semi_plus_space,
395 sep_multiline
396 these options determine the field separators. The first character
397 is between RDNs and the second between multiple AVAs (multiple AVAs
398 are very rare and their use is discouraged). The options ending in
399 "space" additionally place a space after the separator to make it
400 more readable. The sep_multiline uses a linefeed character for the
401 RDN separator and a spaced + for the AVA separator. It also indents
402 the fields by four characters.
403 dn_rev
405 reverse the fields of the DN. This is required by RFC2253. As a
406 side effect this also reverses the order of multiple AVAs but this
407 is permissible.
408 nofname, sname, lname, oid
410 these options alter how the field name is displayed. nofname does
411 not display the field at all. sname uses the "short name" form (CN
412 for commonName for example). lname uses the long form. oid
413 represents the OID in numerical form and is useful for diagnostic
414 purpose.
415 align
417 align field values for a more readable output. Only usable with
418 sep_multiline.
419 space_eq
421 places spaces round the = character which follows the field name.
422 TEXT OPTIONS
424 As well as customising the name output format, it is also possible to
425 customise the actual fields printed using the certopt options when the
426 text option is present. The default behaviour is to print all fields.
427 compatible
429 use the old format. This is equivalent to specifying no output
430 options at all.
431 no_header
433 don't print header information: that is the lines saying
434 "Certificate" and "Data".
435 no_version
437 don't print out the version number.
438 no_serial
440 don't print out the serial number.
441 no_signame
443 don't print out the signature algorithm used.
444 no_validity
446 don't print the validity, that is the notBefore and notAfter
447 fields.
448 no_subject
450 don't print out the subject name.
451 no_issuer
453 don't print out the issuer name.
454 no_pubkey
456 don't print out the public key.
457 no_sigdump
459 don't give a hexadecimal dump of the certificate signature.
460 no_aux
462 don't print out certificate trust information.
463 no_extensions
465 don't print out any X509V3 extensions.
466 ext_default
468 retain default extension behaviour: attempt to print out
469 unsupported certificate extensions.
470 ext_error
472 print an error message for unsupported certificate extensions.
473 ext_parse
475 ASN1 parse unsupported extensions.
476 ext_dump
478 hex dump unsupported extensions.
479 ca_default
481 the value used by the ca utility, equivalent to no_issuer,
482 no_pubkey, no_header, no_version, no_sigdump and no_signame.
483
485 Note: in these examples the '\' means the example should be all on one
486 line.
487 Display the contents of a certificate:
489 openssl x509 -in cert.pem -noout -text
491 Display the certificate serial number:
493 openssl x509 -in cert.pem -noout -serial
495 Display the certificate subject name:
497 openssl x509 -in cert.pem -noout -subject
499 Display the certificate subject name in RFC2253 form:
501 openssl x509 -in cert.pem -noout -subject -nameopt RFC2253
503 Display the certificate subject name in oneline form on a terminal
505 supporting UTF8:
506 openssl x509 -in cert.pem -noout -subject -nameopt oneline,-esc_msb
508 Display the certificate MD5 fingerprint:
510 openssl x509 -in cert.pem -noout -fingerprint
512 Display the certificate SHA1 fingerprint:
514 openssl x509 -sha1 -in cert.pem -noout -fingerprint
516 Convert a certificate from PEM to DER format:
518 openssl x509 -in cert.pem -inform PEM -out cert.der -outform DER
520 Convert a certificate to a certificate request:
522 openssl x509 -x509toreq -in cert.pem -out req.pem -signkey key.pem
524 Convert a certificate request into a self signed certificate using
526 extensions for a CA:
527 openssl x509 -req -in careq.pem -extfile openssl.cnf -extensions v3_ca \
529 -signkey key.pem -out cacert.pem
530 Sign a certificate request using the CA certificate above and add user
532 certificate extensions:
533 openssl x509 -req -in req.pem -extfile openssl.cnf -extensions v3_usr \
535 -CA cacert.pem -CAkey key.pem -CAcreateserial
536 Set a certificate to be trusted for SSL client use and change set its
538 alias to "Steve's Class 1 CA"
539 openssl x509 -in cert.pem -addtrust clientAuth \
541 -setalias "Steve's Class 1 CA" -out trust.pem
542
544 The PEM format uses the header and footer lines:
545 -----BEGIN CERTIFICATE-----
547 -----END CERTIFICATE-----
548 it will also handle files containing:
550 -----BEGIN X509 CERTIFICATE-----
552 -----END X509 CERTIFICATE-----
553 Trusted certificates have the lines
555 -----BEGIN TRUSTED CERTIFICATE-----
557 -----END TRUSTED CERTIFICATE-----
558 The conversion to UTF8 format used with the name options assumes that
560 T61Strings use the ISO8859-1 character set. This is wrong but Netscape
561 and MSIE do this as do many certificates. So although this is incorrect
562 it is more likely to display the majority of certificates correctly.
563 The -fingerprint option takes the digest of the DER encoded
565 certificate. This is commonly called a "fingerprint". Because of the
566 nature of message digests the fingerprint of a certificate is unique to
567 that certificate and two certificates with the same fingerprint can be
568 considered to be the same.
569 The Netscape fingerprint uses MD5 whereas MSIE uses SHA1.
571 The -email option searches the subject name and the subject alternative
573 name extension. Only unique email addresses will be printed out: it
574 will not print the same address more than once.
575
577 The -purpose option checks the certificate extensions and determines
578 what the certificate can be used for. The actual checks done are rather
579 complex and include various hacks and workarounds to handle broken
580 certificates and software.
581 The same code is used when verifying untrusted certificates in chains
583 so this section is useful if a chain is rejected by the verify code.
584 The basicConstraints extension CA flag is used to determine whether the
586 certificate can be used as a CA. If the CA flag is true then it is a
587 CA, if the CA flag is false then it is not a CA. All CAs should have
588 the CA flag set to true.
589 If the basicConstraints extension is absent then the certificate is
591 considered to be a "possible CA" other extensions are checked according
592 to the intended use of the certificate. A warning is given in this case
593 because the certificate should really not be regarded as a CA: however
594 it is allowed to be a CA to work around some broken software.
595 If the certificate is a V1 certificate (and thus has no extensions) and
597 it is self signed it is also assumed to be a CA but a warning is again
598 given: this is to work around the problem of Verisign roots which are
599 V1 self signed certificates.
600 If the keyUsage extension is present then additional restraints are
602 made on the uses of the certificate. A CA certificate must have the
603 keyCertSign bit set if the keyUsage extension is present.
604 The extended key usage extension places additional restrictions on the
606 certificate uses. If this extension is present (whether critical or
607 not) the key can only be used for the purposes specified.
608 A complete description of each test is given below. The comments about
610 basicConstraints and keyUsage and V1 certificates above apply to all CA
611 certificates.
612 SSL Client
614 The extended key usage extension must be absent or include the "web
615 client authentication" OID. keyUsage must be absent or it must
616 have the digitalSignature bit set. Netscape certificate type must
617 be absent or it must have the SSL client bit set.
618 SSL Client CA
620 The extended key usage extension must be absent or include the "web
621 client authentication" OID. Netscape certificate type must be
622 absent or it must have the SSL CA bit set: this is used as a work
623 around if the basicConstraints extension is absent.
624 SSL Server
626 The extended key usage extension must be absent or include the "web
627 server authentication" and/or one of the SGC OIDs. keyUsage must
628 be absent or it must have the digitalSignature, the keyEncipherment
629 set or both bits set. Netscape certificate type must be absent or
630 have the SSL server bit set.
631 SSL Server CA
633 The extended key usage extension must be absent or include the "web
634 server authentication" and/or one of the SGC OIDs. Netscape
635 certificate type must be absent or the SSL CA bit must be set: this
636 is used as a work around if the basicConstraints extension is
637 absent.
638 Netscape SSL Server
640 For Netscape SSL clients to connect to an SSL server it must have
641 the keyEncipherment bit set if the keyUsage extension is present.
642 This isn't always valid because some cipher suites use the key for
643 digital signing. Otherwise it is the same as a normal SSL server.
644 Common S/MIME Client Tests
646 The extended key usage extension must be absent or include the
647 "email protection" OID. Netscape certificate type must be absent or
648 should have the S/MIME bit set. If the S/MIME bit is not set in
649 netscape certificate type then the SSL client bit is tolerated as
650 an alternative but a warning is shown: this is because some
651 Verisign certificates don't set the S/MIME bit.
652 S/MIME Signing
654 In addition to the common S/MIME client tests the digitalSignature
655 bit must be set if the keyUsage extension is present.
656 S/MIME Encryption
658 In addition to the common S/MIME tests the keyEncipherment bit must
659 be set if the keyUsage extension is present.
660 S/MIME CA
662 The extended key usage extension must be absent or include the
663 "email protection" OID. Netscape certificate type must be absent or
664 must have the S/MIME CA bit set: this is used as a work around if
665 the basicConstraints extension is absent.
666 CRL Signing
668 The keyUsage extension must be absent or it must have the CRL
669 signing bit set.
670 CRL Signing CA
672 The normal CA tests apply. Except in this case the basicConstraints
673 extension must be present.
674
676 Extensions in certificates are not transferred to certificate requests
677 and vice versa.
678 It is possible to produce invalid certificates or requests by
680 specifying the wrong private key or using inconsistent options in some
681 cases: these should be checked.
682 There should be options to explicitly set such things as start and end
684 dates rather than an offset from the current time.
685 The code to implement the verify behaviour described in the TRUST
687 SETTINGS is currently being developed. It thus describes the intended
688 behaviour rather than the current behaviour. It is hoped that it will
689 represent reality in OpenSSL 0.9.5 and later.
690
692 req(1), ca(1), genrsa(1), gendsa(1), verify(1), x509v3_config(5)
693
695 Before OpenSSL 0.9.8, the default digest for RSA keys was MD5.
696 The hash algorithm used in the -subject_hash and -issuer_hash options
698 before OpenSSL 1.0.0 was based on the deprecated MD5 algorithm and the
699 encoding of the distinguished name. In OpenSSL 1.0.0 and later it is
700 based on a canonical version of the DN using SHA1. This means that any
701 directories using the old form must have their links rebuilt using
702 c_rehash or similar.
7031.0.1e 2017-03-22 X509(1)