5 openssl-x509 - Certificate display and signing utility
11 [B<-inform> B<DER>|B<PEM>]
12 [B<-outform> B<DER>|B<PEM>]
13 [B<-keyform> B<DER>|B<PEM>]
14 [B<-CAform> B<DER>|B<PEM>]
15 [B<-CAkeyform> B<DER>|B<PEM>]
25 [B<-nameopt> I<option>]
42 [B<-addreject> I<arg>]
46 [B<-signkey> I<filename>]
51 [B<-CAkey> I<filename>]
53 [B<-CAserial> I<filename>]
55 [B<-force_pubkey> I<filename>]
58 [B<-ext> I<extensions>]
59 [B<-certopt> I<option>]
63 [B<-extfile> I<filename>]
64 [B<-extensions> I<section>]
65 [B<-sigopt> I<nm>:I<v>]
67 [B<-writerand> I<file>]
71 =for openssl ifdef engine subject_hash_old issuer_hash_old
75 This command is a multi purpose certificate utility. It can
76 be used to display certificate information, convert certificates to
77 various forms, sign certificate requests like a "mini CA" or edit
78 certificate trust settings.
80 Since there are a large number of options they will split up into
85 =head2 Input, Output, and General Purpose Options
91 Print out a usage message.
93 =item B<-inform> B<DER>|B<PEM>, B<-outform> B<DER>|B<PEM>
95 The input and formats; the default is B<PEM>.
96 See L<openssl(1)/Format Options> for details.
98 The input is normally an X.509 certificate, but this can change if other
99 options such as B<-req> are used.
101 =item B<-in> I<filename>
103 This specifies the input filename to read a certificate from or standard input
104 if this option is not specified.
106 =item B<-out> I<filename>
108 This specifies the output filename to write to or standard output by
114 This affects any signing or display option that uses a message
115 digest, such as the B<-fingerprint>, B<-signkey> and B<-CA> options.
116 Any digest supported by the L<openssl-dgst(1)> command can be used.
117 If not specified then SHA1 is used with B<-fingerprint> or
118 the default digest for the signing algorithm is used, typically SHA256.
120 =item B<-rand> I<files>, B<-writerand> I<file>
122 See L<openssl(1)/Random State Options> for more information.
124 =item B<-engine> I<id>
126 Specifying an engine (by its unique I<id> string) will cause this command
127 to attempt to obtain a functional reference to the specified engine,
128 thus initialising it if needed. The engine will then be set as the default
129 for all available algorithms.
131 =item B<-preserve_dates>
133 When signing a certificate, preserve the "notBefore" and "notAfter" dates
134 instead of adjusting them to current time and duration.
135 Cannot be used with the B<-days> option.
139 =head2 Display Options
141 Note: the B<-alias> and B<-purpose> options are also display options
142 but are described in the L</Trust Settings> section.
148 Prints out the certificate in text form. Full details are output including the
149 public key, signature algorithms, issuer and subject names, serial number
150 any extensions present and any trust settings.
152 =item B<-ext> I<extensions>
154 Prints out the certificate extensions in text form. Extensions are specified
155 with a comma separated string, e.g., "subjectAltName,subjectKeyIdentifier".
156 See the L<x509v3_config(5)> manual page for the extension names.
158 =item B<-certopt> I<option>
160 Customise the output format used with B<-text>. The I<option> argument
161 can be a single option or multiple options separated by commas. The
162 B<-certopt> switch may be also be used more than once to set multiple
163 options. See the L</Text Options> section for more information.
167 This option prevents output of the encoded version of the certificate.
171 Outputs the certificate's SubjectPublicKeyInfo block in PEM format.
175 This option prints out the value of the modulus of the public key
176 contained in the certificate.
180 Outputs the certificate serial number.
182 =item B<-subject_hash>
184 Outputs the "hash" of the certificate subject name. This is used in OpenSSL to
185 form an index to allow certificates in a directory to be looked up by subject
188 =item B<-issuer_hash>
190 Outputs the "hash" of the certificate issuer name.
194 Outputs the OCSP hash values for the subject name and public key.
198 Synonym for "-subject_hash" for backward compatibility reasons.
200 =item B<-subject_hash_old>
202 Outputs the "hash" of the certificate subject name using the older algorithm
203 as used by OpenSSL before version 1.0.0.
205 =item B<-issuer_hash_old>
207 Outputs the "hash" of the certificate issuer name using the older algorithm
208 as used by OpenSSL before version 1.0.0.
212 Outputs the subject name.
216 Outputs the issuer name.
218 =item B<-nameopt> I<option>
220 Option which determines how the subject or issuer names are displayed. The
221 I<option> argument can be a single option or multiple options separated by
222 commas. Alternatively the B<-nameopt> switch may be used more than once to
223 set multiple options. See the L</Name Options> section for more information.
227 Outputs the email address(es) if any.
231 Outputs the OCSP responder address(es) if any.
235 Prints out the start date of the certificate, that is the notBefore date.
239 Prints out the expiry date of the certificate, that is the notAfter date.
243 Prints out the start and expiry dates of a certificate.
245 =item B<-checkend> I<arg>
247 Checks if the certificate expires within the next I<arg> seconds and exits
248 nonzero if yes it will expire or zero if not.
250 =item B<-fingerprint>
252 Calculates and outputs the digest of the DER encoded version of the entire
253 certificate (see digest options).
254 This is commonly called a "fingerprint". Because of the nature of message
255 digests, the fingerprint of a certificate is unique to that certificate and
256 two certificates with the same fingerprint can be considered to be the same.
260 This outputs the certificate in the form of a C source file.
264 =head2 Trust Settings
266 A B<trusted certificate> is an ordinary certificate which has several
267 additional pieces of information attached to it such as the permitted
268 and prohibited uses of the certificate and an "alias".
270 Normally when a certificate is being verified at least one certificate
271 must be "trusted". By default a trusted certificate must be stored
272 locally and must be a root CA: any certificate chain ending in this CA
273 is then usable for any purpose.
275 Trust settings currently are only used with a root CA. They allow a finer
276 control over the purposes the root CA can be used for. For example a CA
277 may be trusted for SSL client but not SSL server use.
279 See the description in L<openssl-verify(1)> for more information
280 on the meaning of trust settings.
282 Future versions of OpenSSL will recognize trust settings on any
283 certificate: not just root CAs.
290 Output a B<trusted> certificate rather than an ordinary. An ordinary
291 or trusted certificate can be input but by default an ordinary
292 certificate is output and any trust settings are discarded. With the
293 B<-trustout> option a trusted certificate is output. A trusted
294 certificate is automatically output if any trust settings are modified.
296 =item B<-setalias> I<arg>
298 Sets the alias of the certificate. This will allow the certificate
299 to be referred to using a nickname for example "Steve's Certificate".
303 Outputs the certificate alias, if any.
307 Clears all the permitted or trusted uses of the certificate.
311 Clears all the prohibited or rejected uses of the certificate.
313 =item B<-addtrust> I<arg>
315 Adds a trusted certificate use.
316 Any object name can be used here but currently only B<clientAuth> (SSL client
317 use), B<serverAuth> (SSL server use), B<emailProtection> (S/MIME email) and
318 B<anyExtendedKeyUsage> are used.
319 As of OpenSSL 1.1.0, the last of these blocks all purposes when rejected or
320 enables all purposes when trusted.
321 Other OpenSSL applications may define additional uses.
323 =item B<-addreject> I<arg>
325 Adds a prohibited use. It accepts the same values as the B<-addtrust>
330 This option performs tests on the certificate extensions and outputs
331 the results. For a more complete description see the
332 L</CERTIFICATE EXTENSIONS> section.
336 =head2 Signing Options
338 This command can be used to sign certificates and requests: it
339 can thus behave like a "mini CA".
343 =item B<-signkey> I<filename>
345 This option causes the input file to be self signed using the supplied
348 It sets the issuer name to the subject name (i.e., makes it self-issued)
349 and changes the public key to the supplied value (unless overridden by
350 B<-force_pubkey>). It sets the validity start date to the current time
351 and the end date to a value determined by the B<-days> option.
352 It retains any certificate extensions unless the B<-clrext> option is supplied;
353 this includes, for example, any existing key identifier extensions.
355 =item B<-sigopt> I<nm>:I<v>
357 Pass options to the signature algorithm during sign or verify operations.
358 Names and values of these options are algorithm-specific.
360 =item B<-passin> I<arg>
362 The key password source. For more information about the format of I<arg>
363 see L<openssl(1)/Pass Phrase Options>.
367 Delete any extensions from a certificate. This option is used when a
368 certificate is being created from another certificate (for example with
369 the B<-signkey> or the B<-CA> options). Normally all extensions are
372 =item B<-keyform> B<DER>|B<PEM>
374 The key format; the default is B<PEM>.
375 See L<openssl(1)/Format Options> for details.
377 =item B<-CAform> B<DER>|B<PEM>, B<-CAkeyform> B<DER>|B<PEM>
379 The format for the CA certificate and key; the default is B<PEM>.
380 See L<openssl(1)/Format Options> for details.
382 =item B<-days> I<arg>
384 Specifies the number of days to make a certificate valid for. The default
385 is 30 days. Cannot be used with the B<-preserve_dates> option.
389 Converts a certificate into a certificate request. The B<-signkey> option
390 is used to pass the required private key.
394 By default a certificate is expected on input. With this option a
395 certificate request is expected instead.
397 =item B<-set_serial> I<n>
399 Specifies the serial number to use. This option can be used with either
400 the B<-signkey> or B<-CA> options. If used in conjunction with the B<-CA>
401 option the serial number file (as specified by the B<-CAserial> or
402 B<-CAcreateserial> options) is not used.
404 The serial number can be decimal or hex (if preceded by C<0x>).
406 =item B<-CA> I<filename>
408 Specifies the CA certificate to be used for signing. When this option is
409 present, this command behaves like a "mini CA". The input file is signed by
410 this CA using this option: that is its issuer name is set to the subject name
411 of the CA and it is digitally signed using the CAs private key.
413 This option is normally combined with the B<-req> option. Without the
414 B<-req> option the input is a certificate which must be self signed.
416 =item B<-CAkey> I<filename>
418 Sets the CA private key to sign a certificate with. If this option is
419 not specified then it is assumed that the CA private key is present in
420 the CA certificate file.
422 =item B<-CAserial> I<filename>
424 Sets the CA serial number file to use.
426 When the B<-CA> option is used to sign a certificate it uses a serial
427 number specified in a file. This file consists of one line containing
428 an even number of hex digits with the serial number to use. After each
429 use the serial number is incremented and written out to the file again.
431 The default filename consists of the CA certificate file base name with
432 F<.srl> appended. For example if the CA certificate file is called
433 F<mycacert.pem> it expects to find a serial number file called
436 =item B<-CAcreateserial>
438 With this option the CA serial number file is created if it does not exist:
439 it will contain the serial number "02" and the certificate being signed will
440 have the 1 as its serial number. If the B<-CA> option is specified
441 and the serial number file does not exist a random number is generated;
442 this is the recommended practice.
444 =item B<-extfile> I<filename>
446 File containing certificate extensions to use. If not specified then
447 no extensions are added to the certificate.
449 =item B<-extensions> I<section>
451 The section to add certificate extensions from. If this option is not
452 specified then the extensions should either be contained in the unnamed
453 (default) section or the default section should contain a variable called
454 "extensions" which contains the section to use. See the
455 L<x509v3_config(5)> manual page for details of the
456 extension section format.
460 Generate a certificate from scratch, not using an input certificate
461 or certificate request. So the B<-in> option must not be used in this case.
462 Instead, the B<-subj> and <-force_pubkey> options need to be given.
464 =item B<-force_pubkey> I<filename>
466 When a certificate is created set its public key to the key in I<filename>
467 instead of the key contained in the input or given with the B<-signkey> option.
469 This option is useful for creating self-issued certificates that are not
470 self-signed, for instance when the key cannot be used for signing, such as DH.
471 It can also be used in conjunction with b<-new> and B<-subj> to directly
472 generate a certificate containing any desired public key.
474 The format of the key file can be specified using the B<-keyform> option.
476 =item B<-subj> I<arg>
478 When a certificate is created set its subject name to the given value.
479 The arg must be formatted as C</type0=value0/type1=value1/type2=...>.
480 Keyword characters may be escaped by \ (backslash), and whitespace is retained.
481 Empty values are permitted, but the corresponding type will not be included
482 in the certificate. Giving a single C</> will lead to an empty sequence of RDNs
485 Unless the B<-CA> option is given the issuer is set to the same value.
487 This option can be used in conjunction with the B<-force_pubkey> option
488 to create a certificate even without providing an input certificate
489 or certificate request.
495 The B<-nameopt> command line switch determines how the subject and issuer
496 names are displayed. If no B<-nameopt> switch is present the default "oneline"
497 format is used which is compatible with previous versions of OpenSSL.
498 Each option is described in detail below, all options can be preceded by
499 a B<-> to turn the option off. Only the first four will normally be used.
509 Displays names compatible with RFC2253 equivalent to B<esc_2253>, B<esc_ctrl>,
510 B<esc_msb>, B<utf8>, B<dump_nostr>, B<dump_unknown>, B<dump_der>,
511 B<sep_comma_plus>, B<dn_rev> and B<sname>.
515 A oneline format which is more readable than RFC2253. It is equivalent to
516 specifying the B<esc_2253>, B<esc_ctrl>, B<esc_msb>, B<utf8>, B<dump_nostr>,
517 B<dump_der>, B<use_quote>, B<sep_comma_plus_space>, B<space_eq> and B<sname>
518 options. This is the I<default> of no name options are given explicitly.
522 A multiline format. It is equivalent B<esc_ctrl>, B<esc_msb>, B<sep_multiline>,
523 B<space_eq>, B<lname> and B<align>.
527 Escape the "special" characters required by RFC2253 in a field. That is
528 B<,+"E<lt>E<gt>;>. Additionally B<#> is escaped at the beginning of a string
529 and a space character at the beginning or end of a string.
533 Escape the "special" characters required by RFC2254 in a field. That is
534 the B<NUL> character as well as and B<()*>.
538 Escape control characters. That is those with ASCII values less than
539 0x20 (space) and the delete (0x7f) character. They are escaped using the
540 RFC2253 \XX notation (where XX are two hex digits representing the
545 Escape characters with the MSB set, that is with ASCII values larger than
550 Escapes some characters by surrounding the whole string with B<"> characters,
551 without the option all escaping is done with the B<\> character.
555 Convert all strings to UTF8 format first. This is required by RFC2253. If
556 you are lucky enough to have a UTF8 compatible terminal then the use
557 of this option (and B<not> setting B<esc_msb>) may result in the correct
558 display of multibyte (international) characters. Is this option is not
559 present then multibyte characters larger than 0xff will be represented
560 using the format \UXXXX for 16 bits and \WXXXXXXXX for 32 bits.
561 Also if this option is off any UTF8Strings will be converted to their
562 character form first.
566 This option does not attempt to interpret multibyte characters in any
567 way. That is their content octets are merely dumped as though one octet
568 represents each character. This is useful for diagnostic purposes but
569 will result in rather odd looking output.
573 Show the type of the ASN1 character string. The type precedes the
574 field contents. For example "BMPSTRING: Hello World".
578 When this option is set any fields that need to be hexdumped will
579 be dumped using the DER encoding of the field. Otherwise just the
580 content octets will be displayed. Both options use the RFC2253
585 Dump non character string types (for example OCTET STRING) if this
586 option is not set then non character string types will be displayed
587 as though each content octet represents a single character.
591 Dump all fields. This option when used with B<dump_der> allows the
592 DER encoding of the structure to be unambiguously determined.
594 =item B<dump_unknown>
596 Dump any field whose OID is not recognised by OpenSSL.
598 =item B<sep_comma_plus>, B<sep_comma_plus_space>, B<sep_semi_plus_space>,
601 These options determine the field separators. The first character is
602 between Relative Distinguished Names (RDNs) and the second is between
603 multiple Attribute Value Assertions (AVAs, multiple AVAs are
604 very rare and their use is discouraged). The options ending in
605 "space" additionally place a space after the separator to make it
606 more readable. The B<sep_multiline> uses a linefeed character for
607 the RDN separator and a spaced B<+> for the AVA separator. It also
608 indents the fields by four characters. If no field separator is specified
609 then B<sep_comma_plus_space> is used by default.
613 Reverse the fields of the DN. This is required by RFC2253. As a side
614 effect this also reverses the order of multiple AVAs but this is
617 =item B<nofname>, B<sname>, B<lname>, B<oid>
619 These options alter how the field name is displayed. B<nofname> does
620 not display the field at all. B<sname> uses the "short name" form
621 (CN for commonName for example). B<lname> uses the long form.
622 B<oid> represents the OID in numerical form and is useful for
627 Align field values for a more readable output. Only usable with
632 Places spaces round the B<=> character which follows the field
639 As well as customising the name output format, it is also possible to
640 customise the actual fields printed using the B<certopt> options when
641 the B<text> option is present. The default behaviour is to print all fields.
647 Use the old format. This is equivalent to specifying no output options at all.
651 Don't print header information: that is the lines saying "Certificate"
656 Don't print out the version number.
660 Don't print out the serial number.
664 Don't print out the signature algorithm used.
668 Don't print the validity, that is the B<notBefore> and B<notAfter> fields.
672 Don't print out the subject name.
676 Don't print out the issuer name.
680 Don't print out the public key.
684 Don't give a hexadecimal dump of the certificate signature.
688 Don't print out certificate trust information.
690 =item B<no_extensions>
692 Don't print out any X509V3 extensions.
696 Retain default extension behaviour: attempt to print out unsupported
697 certificate extensions.
701 Print an error message for unsupported certificate extensions.
705 ASN1 parse unsupported extensions.
709 Hex dump unsupported extensions.
713 The value used by L<openssl-ca(1)>, equivalent to B<no_issuer>, B<no_pubkey>,
714 B<no_header>, and B<no_version>.
720 Note: in these examples the '\' means the example should be all on one
723 Display the contents of a certificate:
725 openssl x509 -in cert.pem -noout -text
727 Display the "Subject Alternative Name" extension of a certificate:
729 openssl x509 -in cert.pem -noout -ext subjectAltName
731 Display more extensions of a certificate:
733 openssl x509 -in cert.pem -noout -ext subjectAltName,nsCertType
735 Display the certificate serial number:
737 openssl x509 -in cert.pem -noout -serial
739 Display the certificate subject name:
741 openssl x509 -in cert.pem -noout -subject
743 Display the certificate subject name in RFC2253 form:
745 openssl x509 -in cert.pem -noout -subject -nameopt RFC2253
747 Display the certificate subject name in oneline form on a terminal
750 openssl x509 -in cert.pem -noout -subject -nameopt oneline,-esc_msb
752 Display the certificate SHA1 fingerprint:
754 openssl x509 -sha1 -in cert.pem -noout -fingerprint
756 Convert a certificate from PEM to DER format:
758 openssl x509 -in cert.pem -inform PEM -out cert.der -outform DER
760 Convert a certificate to a certificate request:
762 openssl x509 -x509toreq -in cert.pem -out req.pem -signkey key.pem
764 Convert a certificate request into a self signed certificate using
767 openssl x509 -req -in careq.pem -extfile openssl.cnf -extensions v3_ca \
768 -signkey key.pem -out cacert.pem
770 Sign a certificate request using the CA certificate above and add user
771 certificate extensions:
773 openssl x509 -req -in req.pem -extfile openssl.cnf -extensions v3_usr \
774 -CA cacert.pem -CAkey key.pem -CAcreateserial
777 Set a certificate to be trusted for SSL client use and change set its alias to
780 openssl x509 -in cert.pem -addtrust clientAuth \
781 -setalias "Steve's Class 1 CA" -out trust.pem
785 The conversion to UTF8 format used with the name options assumes that
786 T61Strings use the ISO8859-1 character set. This is wrong but Netscape
787 and MSIE do this as do many certificates. So although this is incorrect
788 it is more likely to display the majority of certificates correctly.
790 The B<-email> option searches the subject name and the subject alternative
791 name extension. Only unique email addresses will be printed out: it will
792 not print the same address more than once.
794 =head1 CERTIFICATE EXTENSIONS
796 The B<-purpose> option checks the certificate extensions and determines
797 what the certificate can be used for. The actual checks done are rather
798 complex and include various hacks and workarounds to handle broken
799 certificates and software.
801 The same code is used when verifying untrusted certificates in chains
802 so this section is useful if a chain is rejected by the verify code.
804 The basicConstraints extension CA flag is used to determine whether the
805 certificate can be used as a CA. If the CA flag is true then it is a CA,
806 if the CA flag is false then it is not a CA. B<All> CAs should have the
809 If the basicConstraints extension is absent then the certificate is
810 considered to be a "possible CA" other extensions are checked according
811 to the intended use of the certificate. A warning is given in this case
812 because the certificate should really not be regarded as a CA: however
813 it is allowed to be a CA to work around some broken software.
815 If the certificate is a V1 certificate (and thus has no extensions) and
816 it is self signed it is also assumed to be a CA but a warning is again
817 given: this is to work around the problem of Verisign roots which are V1
818 self signed certificates.
820 If the keyUsage extension is present then additional restraints are
821 made on the uses of the certificate. A CA certificate B<must> have the
822 keyCertSign bit set if the keyUsage extension is present.
824 The extended key usage extension places additional restrictions on the
825 certificate uses. If this extension is present (whether critical or not)
826 the key can only be used for the purposes specified.
828 A complete description of each test is given below. The comments about
829 basicConstraints and keyUsage and V1 certificates above apply to B<all>
837 The extended key usage extension must be absent or include the "web client
838 authentication" OID. keyUsage must be absent or it must have the
839 digitalSignature bit set. Netscape certificate type must be absent or it must
840 have the SSL client bit set.
842 =item B<SSL Client CA>
844 The extended key usage extension must be absent or include the "web client
845 authentication" OID. Netscape certificate type must be absent or it must have
846 the SSL CA bit set: this is used as a work around if the basicConstraints
851 The extended key usage extension must be absent or include the "web server
852 authentication" and/or one of the SGC OIDs. keyUsage must be absent or it
853 must have the digitalSignature, the keyEncipherment set or both bits set.
854 Netscape certificate type must be absent or have the SSL server bit set.
856 =item B<SSL Server CA>
858 The extended key usage extension must be absent or include the "web server
859 authentication" and/or one of the SGC OIDs. Netscape certificate type must
860 be absent or the SSL CA bit must be set: this is used as a work around if the
861 basicConstraints extension is absent.
863 =item B<Netscape SSL Server>
865 For Netscape SSL clients to connect to an SSL server it must have the
866 keyEncipherment bit set if the keyUsage extension is present. This isn't
867 always valid because some cipher suites use the key for digital signing.
868 Otherwise it is the same as a normal SSL server.
870 =item B<Common S/MIME Client Tests>
872 The extended key usage extension must be absent or include the "email
873 protection" OID. Netscape certificate type must be absent or should have the
874 S/MIME bit set. If the S/MIME bit is not set in Netscape certificate type
875 then the SSL client bit is tolerated as an alternative but a warning is shown:
876 this is because some Verisign certificates don't set the S/MIME bit.
878 =item B<S/MIME Signing>
880 In addition to the common S/MIME client tests the digitalSignature bit or
881 the nonRepudiation bit must be set if the keyUsage extension is present.
883 =item B<S/MIME Encryption>
885 In addition to the common S/MIME tests the keyEncipherment bit must be set
886 if the keyUsage extension is present.
890 The extended key usage extension must be absent or include the "email
891 protection" OID. Netscape certificate type must be absent or must have the
892 S/MIME CA bit set: this is used as a work around if the basicConstraints
897 The keyUsage extension must be absent or it must have the CRL signing bit
900 =item B<CRL Signing CA>
902 The normal CA tests apply. Except in this case the basicConstraints extension
909 Extensions in certificates are not transferred to certificate requests and
912 It is possible to produce invalid certificates or requests by specifying the
913 wrong private key or using inconsistent options in some cases: these should
916 There should be options to explicitly set such things as start and end
917 dates rather than an offset from the current time.
924 L<openssl-genrsa(1)>,
925 L<openssl-gendsa(1)>,
926 L<openssl-verify(1)>,
931 The hash algorithm used in the B<-subject_hash> and B<-issuer_hash> options
932 before OpenSSL 1.0.0 was based on the deprecated MD5 algorithm and the encoding
933 of the distinguished name. In OpenSSL 1.0.0 and later it is based on a canonical
934 version of the DN using SHA1. This means that any directories using the old
935 form must have their links rebuilt using L<openssl-rehash(1)> or similar.
939 Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
941 Licensed under the Apache License 2.0 (the "License"). You may not use
942 this file except in compliance with the License. You can obtain a copy
943 in the file LICENSE in the source distribution or at
944 L<https://www.openssl.org/source/license.html>.