2 {- OpenSSL::safe::output_do_not_edit_headers(); -}
6 openssl-x509 - Certificate display and signing command
12 [B<-in> I<filename>|I<uri>]
17 [B<-copy_extensions> I<arg>]
18 [B<-inform> B<DER>|B<PEM>]
19 [B<-vfyopt> I<nm>:I<v>]
20 [B<-key> I<filename>|I<uri>]
21 [B<-keyform> B<DER>|B<PEM>|B<P12>|B<ENGINE>]
22 [B<-signkey> I<filename>|I<uri>]
24 [B<-outform> B<DER>|B<PEM>]
28 [B<-certopt> I<option>]
37 {- $OpenSSL::safe::opt_name_synopsis -}
41 [B<-subject_hash_old>]
44 [B<-ext> I<extensions>]
51 [B<-checkhost> I<host>]
52 [B<-checkemail> I<host>]
53 [B<-checkip> I<ipaddr>]
59 [B<-force_pubkey> I<filename>]
61 [B<-extfile> I<filename>]
62 [B<-extensions> I<section>]
63 [B<-sigopt> I<nm>:I<v>]
66 [B<-CA> I<filename>|I<uri>]
67 [B<-CAform> B<DER>|B<PEM>|B<P12>]
68 [B<-CAkey> I<filename>|I<uri>]
69 [B<-CAkeyform> B<DER>|B<PEM>|B<P12>|B<ENGINE>]
70 [B<-CAserial> I<filename>]
77 [B<-addreject> I<arg>]
78 {- $OpenSSL::safe::opt_r_synopsis -}
79 {- $OpenSSL::safe::opt_engine_synopsis -}{- $OpenSSL::safe::opt_provider_synopsis -}
81 =for openssl ifdef engine subject_hash_old issuer_hash_old
85 This command is a multi-purposes certificate handling command.
86 It can be used to print certificate information,
87 convert certificates to various forms, edit certificate trust settings,
88 generate certificates from scratch or from certificating requests
89 and then self-signing them or signing them like a "micro CA".
91 Since there are a large number of options they will split up into
96 =head2 Input, Output, and General Purpose Options
102 Print out a usage message.
104 =item B<-in> I<filename>|I<uri>
106 If the B<-req> option is not used this specifies the input
107 to read a certificate from or standard input if this option is not specified.
108 With the B<-req> option this specifies a certificate request file.
110 =item B<-passin> I<arg>
112 The key and certificate file password source.
113 For more information about the format of I<arg>
114 see L<openssl-passphrase-options(1)>.
118 Generate a certificate from scratch, not using an input certificate
119 or certificate request. So the B<-in> option must not be used in this case.
120 Instead, the B<-subj> option needs to be given.
121 The public key to include can be given with the B<-force_pubkey> option
122 and defaults to the key given with the B<-key> option,
123 which implies self-signature.
127 Output a PKCS#10 certificate request (rather than a certificate).
128 The B<-key> option must be used to provide the private key for self-signing;
129 the corresponding public key is placed in the subjectPKInfo field.
131 X.509 extensions included in a certificate input are not copied by default.
132 X.509 extensions to be added can be specified using the B<-extfile> option.
136 By default a certificate is expected on input.
137 With this option a PKCS#10 certificate request is expected instead,
138 which must be correctly self-signed.
140 X.509 extensions included in the request are not copied by default.
141 X.509 extensions to be added can be specified using the B<-extfile> option.
143 =item B<-copy_extensions> I<arg>
145 Determines how to handle X.509 extensions
146 when converting from a certificate to a request using the B<-x509toreq> option
147 or converting from a request to a certificate using the B<-req> option.
148 If I<arg> is B<none> or this option is not present then extensions are ignored.
149 If I<arg> is B<copy> or B<copyall> then all extensions are copied,
150 except that subject identifier and authority key identifier extensions
151 are not taken over when producing a certificate request.
153 The B<-ext> option can be used to further restrict which extensions to copy.
155 =item B<-inform> B<DER>|B<PEM>
157 The input file format; unspecified by default.
158 See L<openssl-format-options(1)> for details.
160 =item B<-vfyopt> I<nm>:I<v>
162 Pass options to the signature algorithm during verify operations.
163 Names and values of these options are algorithm-specific.
165 =item B<-key> I<filename>|I<uri>
167 This option causes the new certificate or certificate request
168 to be self-signed using the supplied private key.
169 This cannot be used in conjunction with the B<-CA> option.
171 It sets the issuer name to the subject name (i.e., makes it self-issued)
172 and changes the public key to the supplied value (unless overridden
173 by B<-force_pubkey>).
174 Unless the B<-preserve_dates> option is supplied,
175 it sets the validity start date to the current time
176 and the end date to a value determined by the B<-days> option.
178 =item B<-signkey> I<filename>|I<uri>
180 This option is an alias of B<-key>.
182 =item B<-keyform> B<DER>|B<PEM>|B<P12>|B<ENGINE>
184 The key input format; unspecified by default.
185 See L<openssl-format-options(1)> for details.
187 =item B<-out> I<filename>
189 This specifies the output filename to write to or standard output by default.
191 =item B<-outform> B<DER>|B<PEM>
193 The output format; the default is B<PEM>.
194 See L<openssl-format-options(1)> for details.
198 Do not output a certificate (except for printing as requested by below options).
202 This option prevents output except for printing as requested by below options.
206 =head2 Certificate Printing Options
208 Note: the B<-alias> and B<-purpose> options are also printing options
209 but are described in the L</Trust Settings> section.
215 Prints out the certificate in text form. Full details are printed including the
216 public key, signature algorithms, issuer and subject names, serial number
217 any extensions present and any trust settings.
219 =item B<-certopt> I<option>
221 Customise the print format used with B<-text>. The I<option> argument
222 can be a single option or multiple options separated by commas.
223 The B<-certopt> switch may be also be used more than once to set multiple
224 options. See the L</Text Printing Flags> section for more information.
226 =item B<-fingerprint>
228 Calculates and prints the digest of the DER encoded version of the entire
229 certificate (see digest options).
230 This is commonly called a "fingerprint". Because of the nature of message
231 digests, the fingerprint of a certificate is unique to that certificate and
232 two certificates with the same fingerprint can be considered to be the same.
236 Prints the certificate "alias" (nickname), if any.
240 Prints the certificate serial number.
244 Prints out the start date of the certificate, that is the notBefore date.
248 Prints out the expiry date of the certificate, that is the notAfter date.
252 Prints out the start and expiry dates of a certificate.
256 Prints the subject name.
260 Prints the issuer name.
262 {- $OpenSSL::safe::opt_name_item -}
266 Prints the email address(es) if any.
270 Synonym for "-subject_hash" for backward compatibility reasons.
272 =item B<-subject_hash>
274 Prints the "hash" of the certificate subject name. This is used in OpenSSL to
275 form an index to allow certificates in a directory to be looked up by subject
278 =item B<-subject_hash_old>
280 Prints the "hash" of the certificate subject name using the older algorithm
281 as used by OpenSSL before version 1.0.0.
283 =item B<-issuer_hash>
285 Prints the "hash" of the certificate issuer name.
287 =item B<-issuer_hash_old>
289 Prints the "hash" of the certificate issuer name using the older algorithm
290 as used by OpenSSL before version 1.0.0.
292 =item B<-ext> I<extensions>
294 Prints out the certificate extensions in text form.
295 Can also be used to restrict which extensions to copy.
296 Extensions are specified
297 with a comma separated string, e.g., "subjectAltName,subjectKeyIdentifier".
298 See the L<x509v3_config(5)> manual page for the extension names.
302 Prints the OCSP hash values for the subject name and public key.
306 Prints the OCSP responder address(es) if any.
310 This option performs tests on the certificate extensions and prints
311 the results. For a more complete description see the
312 L</CERTIFICATE EXTENSIONS> section.
316 Prints the certificate's SubjectPublicKeyInfo block in PEM format.
320 This option prints out the value of the modulus of the public key
321 contained in the certificate.
325 =head2 Certificate Checking Options
329 =item B<-checkend> I<arg>
331 Checks if the certificate expires within the next I<arg> seconds and exits
332 nonzero if yes it will expire or zero if not.
334 =item B<-checkhost> I<host>
336 Check that the certificate matches the specified host.
338 =item B<-checkemail> I<email>
340 Check that the certificate matches the specified email address.
342 =item B<-checkip> I<ipaddr>
344 Check that the certificate matches the specified IP address.
348 =head2 Certificate Output Options
352 =item B<-set_serial> I<n>
354 Specifies the serial number to use. This option can be used with either
355 the B<-key> or B<-CA> options. If used in conjunction with the B<-CA> option
356 the serial number file (as specified by the B<-CAserial> option) is not used.
358 The serial number can be decimal or hex (if preceded by C<0x>).
360 =item B<-next_serial>
362 Set the serial to be one more than the number in the certificate.
364 =item B<-days> I<arg>
366 Specifies the number of days until a newly generated certificate expires.
368 Cannot be used together with the B<-preserve_dates> option.
370 =item B<-preserve_dates>
372 When signing a certificate, preserve "notBefore" and "notAfter" dates of any
373 input certificate instead of adjusting them to current time and duration.
374 Cannot be used together with the B<-days> option.
376 =item B<-subj> I<arg>
378 When a certificate is created set its subject name to the given value.
379 When the certificate is self-signed the issuer name is set to the same value.
381 The arg must be formatted as C</type0=value0/type1=value1/type2=...>.
382 Special characters may be escaped by C<\> (backslash), whitespace is retained.
383 Empty values are permitted, but the corresponding type will not be included
385 Giving a single C</> will lead to an empty sequence of RDNs (a NULL-DN).
386 Multi-valued RDNs can be formed by placing a C<+> character instead of a C</>
387 between the AttributeValueAssertions (AVAs) that specify the members of the set.
390 C</DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe>
392 This option can be used in conjunction with the B<-force_pubkey> option
393 to create a certificate even without providing an input certificate
394 or certificate request.
396 =item B<-force_pubkey> I<filename>
398 When a certificate is created set its public key to the key in I<filename>
399 instead of the key contained in the input or given with the B<-key> option.
401 This option is useful for creating self-issued certificates that are not
402 self-signed, for instance when the key cannot be used for signing, such as DH.
403 It can also be used in conjunction with b<-new> and B<-subj> to directly
404 generate a certificate containing any desired public key.
408 When transforming a certificate to a new certificate
409 by default all certificate extensions are retained.
411 When transforming a certificate or certificate request,
412 the B<-clrext> option prevents taking over any extensions from the source.
413 In any case, when producing a certificate request,
414 neither subject identifier nor authority key identifier extensions are included.
416 =item B<-extfile> I<filename>
418 Configuration file containing certificate and request X.509 extensions to add.
420 =item B<-extensions> I<section>
422 The section in the extfile to add X.509 extensions from.
423 If this option is not
424 specified then the extensions should either be contained in the unnamed
425 (default) section or the default section should contain a variable called
426 "extensions" which contains the section to use.
427 See the L<x509v3_config(5)> manual page for details of the
428 extension section format.
430 =item B<-sigopt> I<nm>:I<v>
432 Pass options to the signature algorithm during sign operations.
433 This option may be given multiple times.
434 Names and values provided using this option are algorithm-specific.
438 Corrupt the signature before writing it; this can be useful
444 This affects any signing or printing option that uses a message
445 digest, such as the B<-fingerprint>, B<-key> and B<-CA> options.
446 Any digest supported by the L<openssl-dgst(1)> command can be used.
447 If not specified then SHA1 is used with B<-fingerprint> or
448 the default digest for the signing algorithm is used, typically SHA256.
452 =head2 Micro-CA Options
456 =item B<-CA> I<filename>|I<uri>
458 Specifies the "CA" certificate to be used for signing.
459 When present, this behaves like a "micro CA" as follows:
460 The subject name of the "CA" certificate is placed as issuer name in the new
461 certificate, which is then signed using the "CA" key given as detailed below.
463 This option cannot be used in conjunction with the B<-key> option.
464 This option is normally combined with the B<-req> option referencing a CSR.
465 Without the B<-req> option the input must be a self-signed certificate
466 unless the B<-new> option is given, which generates a certificate from scratch.
468 =item B<-CAform> B<DER>|B<PEM>|B<P12>,
470 The format for the CA certificate; unspecifed by default.
471 See L<openssl-format-options(1)> for details.
473 =item B<-CAkey> I<filename>|I<uri>
475 Sets the CA private key to sign a certificate with.
476 The private key must match the public key of the certificate given with B<-CA>.
477 If this option is not provided then the key must be present in the B<-CA> input.
479 =item B<-CAkeyform> B<DER>|B<PEM>|B<P12>|B<ENGINE>
481 The format for the CA key; unspecified by default.
482 See L<openssl-format-options(1)> for details.
484 =item B<-CAserial> I<filename>
486 Sets the CA serial number file to use.
488 When the B<-CA> option is used to sign a certificate it uses a serial
489 number specified in a file. This file consists of one line containing
490 an even number of hex digits with the serial number to use. After each
491 use the serial number is incremented and written out to the file again.
493 The default filename consists of the CA certificate file base name with
494 F<.srl> appended. For example if the CA certificate file is called
495 F<mycacert.pem> it expects to find a serial number file called
498 =item B<-CAcreateserial>
500 With this option the CA serial number file is created if it does not exist:
501 it will contain the serial number "02" and the certificate being signed will
502 have the 1 as its serial number. If the B<-CA> option is specified
503 and the serial number file does not exist a random number is generated;
504 this is the recommended practice.
508 =head2 Trust Settings
510 A B<trusted certificate> is an ordinary certificate which has several
511 additional pieces of information attached to it such as the permitted
512 and prohibited uses of the certificate and possibly an "alias" (nickname).
514 Normally when a certificate is being verified at least one certificate
515 must be "trusted". By default a trusted certificate must be stored
516 locally and must be a root CA: any certificate chain ending in this CA
517 is then usable for any purpose.
519 Trust settings currently are only used with a root CA.
520 They allow a finer control over the purposes the root CA can be used for.
521 For example, a CA may be trusted for SSL client but not SSL server use.
523 See the description in L<openssl-verify(1)> for more information
524 on the meaning of trust settings.
526 Future versions of OpenSSL will recognize trust settings on any
527 certificate: not just root CAs.
533 Mark any certificate PEM output as <trusted> certificate rather than ordinary.
534 An ordinary or trusted certificate can be input but by default an ordinary
535 certificate is output and any trust settings are discarded.
536 With the B<-trustout> option a trusted certificate is output. A trusted
537 certificate is automatically output if any trust settings are modified.
539 =item B<-setalias> I<arg>
541 Sets the "alias" of the certificate. This will allow the certificate
542 to be referred to using a nickname for example "Steve's Certificate".
546 Clears all the permitted or trusted uses of the certificate.
548 =item B<-addtrust> I<arg>
550 Adds a trusted certificate use.
551 Any object name can be used here but currently only B<clientAuth> (SSL client
552 use), B<serverAuth> (SSL server use), B<emailProtection> (S/MIME email)
553 and B<anyExtendedKeyUsage> are used.
554 As of OpenSSL 1.1.0, the last of these blocks all purposes when rejected or
555 enables all purposes when trusted.
556 Other OpenSSL applications may define additional uses.
560 Clears all the prohibited or rejected uses of the certificate.
562 =item B<-addreject> I<arg>
564 Adds a prohibited use.
565 It accepts the same values as the B<-addtrust> option.
569 =head2 Generic options
573 {- $OpenSSL::safe::opt_r_item -}
575 {- $OpenSSL::safe::opt_engine_item -}
577 {- $OpenSSL::safe::opt_provider_item -}
581 =head2 Text Printing Flags
583 As well as customising the name printing format, it is also possible to
584 customise the actual fields printed using the B<certopt> option when
585 the B<text> option is present. The default behaviour is to print all fields.
591 Use the old format. This is equivalent to specifying no printing options at all.
595 Don't print header information: that is the lines saying "Certificate"
600 Don't print out the version number.
604 Don't print out the serial number.
608 Don't print out the signature algorithm used.
612 Don't print the validity, that is the B<notBefore> and B<notAfter> fields.
616 Don't print out the subject name.
620 Don't print out the issuer name.
624 Don't print out the public key.
628 Don't give a hexadecimal dump of the certificate signature.
632 Don't print out certificate trust information.
634 =item B<no_extensions>
636 Don't print out any X509V3 extensions.
640 Retain default extension behaviour: attempt to print out unsupported
641 certificate extensions.
645 Print an error message for unsupported certificate extensions.
649 ASN1 parse unsupported extensions.
653 Hex dump unsupported extensions.
657 The value used by L<openssl-ca(1)>, equivalent to B<no_issuer>, B<no_pubkey>,
658 B<no_header>, and B<no_version>.
664 Note: in these examples the '\' means the example should be all on one
667 Print the contents of a certificate:
669 openssl x509 -in cert.pem -noout -text
671 Print the "Subject Alternative Name" extension of a certificate:
673 openssl x509 -in cert.pem -noout -ext subjectAltName
675 Print more extensions of a certificate:
677 openssl x509 -in cert.pem -noout -ext subjectAltName,nsCertType
679 Print the certificate serial number:
681 openssl x509 -in cert.pem -noout -serial
683 Print the certificate subject name:
685 openssl x509 -in cert.pem -noout -subject
687 Print the certificate subject name in RFC2253 form:
689 openssl x509 -in cert.pem -noout -subject -nameopt RFC2253
691 Print the certificate subject name in oneline form on a terminal
694 openssl x509 -in cert.pem -noout -subject -nameopt oneline,-esc_msb
696 Print the certificate SHA1 fingerprint:
698 openssl x509 -sha1 -in cert.pem -noout -fingerprint
700 Convert a certificate from PEM to DER format:
702 openssl x509 -in cert.pem -inform PEM -out cert.der -outform DER
704 Convert a certificate to a certificate request:
706 openssl x509 -x509toreq -in cert.pem -out req.pem -key key.pem
708 Convert a certificate request into a self-signed certificate using
711 openssl x509 -req -in careq.pem -extfile openssl.cnf -extensions v3_ca \
712 -key key.pem -out cacert.pem
714 Sign a certificate request using the CA certificate above and add user
715 certificate extensions:
717 openssl x509 -req -in req.pem -extfile openssl.cnf -extensions v3_usr \
718 -CA cacert.pem -CAkey key.pem -CAcreateserial
720 Set a certificate to be trusted for SSL client use and change set its alias to
723 openssl x509 -in cert.pem -addtrust clientAuth \
724 -setalias "Steve's Class 1 CA" -out trust.pem
728 The conversion to UTF8 format used with the name options assumes that
729 T61Strings use the ISO8859-1 character set. This is wrong but Netscape
730 and MSIE do this as do many certificates. So although this is incorrect
731 it is more likely to print the majority of certificates correctly.
733 The B<-email> option searches the subject name and the subject alternative
734 name extension. Only unique email addresses will be printed out: it will
735 not print the same address more than once.
737 =head1 CERTIFICATE EXTENSIONS
739 The B<-purpose> option checks the certificate extensions and determines
740 what the certificate can be used for. The actual checks done are rather
741 complex and include various hacks and workarounds to handle broken
742 certificates and software.
744 The same code is used when verifying untrusted certificates in chains
745 so this section is useful if a chain is rejected by the verify code.
747 The basicConstraints extension CA flag is used to determine whether the
748 certificate can be used as a CA. If the CA flag is true then it is a CA,
749 if the CA flag is false then it is not a CA. B<All> CAs should have the
752 If the basicConstraints extension is absent then the certificate is
753 considered to be a "possible CA" other extensions are checked according
754 to the intended use of the certificate. A warning is given in this case
755 because the certificate should really not be regarded as a CA: however
756 it is allowed to be a CA to work around some broken software.
758 If the certificate is a V1 certificate (and thus has no extensions) and
759 it is self-signed it is also assumed to be a CA but a warning is again
760 given: this is to work around the problem of Verisign roots which are V1
761 self-signed certificates.
763 If the keyUsage extension is present then additional restraints are
764 made on the uses of the certificate. A CA certificate B<must> have the
765 keyCertSign bit set if the keyUsage extension is present.
767 The extended key usage extension places additional restrictions on the
768 certificate uses. If this extension is present (whether critical or not)
769 the key can only be used for the purposes specified.
771 A complete description of each test is given below. The comments about
772 basicConstraints and keyUsage and V1 certificates above apply to B<all>
780 The extended key usage extension must be absent or include the "web client
781 authentication" OID. keyUsage must be absent or it must have the
782 digitalSignature bit set. Netscape certificate type must be absent or it must
783 have the SSL client bit set.
785 =item B<SSL Client CA>
787 The extended key usage extension must be absent or include the "web client
788 authentication" OID. Netscape certificate type must be absent or it must have
789 the SSL CA bit set: this is used as a work around if the basicConstraints
794 The extended key usage extension must be absent or include the "web server
795 authentication" and/or one of the SGC OIDs. keyUsage must be absent or it
796 must have the digitalSignature, the keyEncipherment set or both bits set.
797 Netscape certificate type must be absent or have the SSL server bit set.
799 =item B<SSL Server CA>
801 The extended key usage extension must be absent or include the "web server
802 authentication" and/or one of the SGC OIDs. Netscape certificate type must
803 be absent or the SSL CA bit must be set: this is used as a work around if the
804 basicConstraints extension is absent.
806 =item B<Netscape SSL Server>
808 For Netscape SSL clients to connect to an SSL server it must have the
809 keyEncipherment bit set if the keyUsage extension is present. This isn't
810 always valid because some cipher suites use the key for digital signing.
811 Otherwise it is the same as a normal SSL server.
813 =item B<Common S/MIME Client Tests>
815 The extended key usage extension must be absent or include the "email
816 protection" OID. Netscape certificate type must be absent or should have the
817 S/MIME bit set. If the S/MIME bit is not set in Netscape certificate type
818 then the SSL client bit is tolerated as an alternative but a warning is shown:
819 this is because some Verisign certificates don't set the S/MIME bit.
821 =item B<S/MIME Signing>
823 In addition to the common S/MIME client tests the digitalSignature bit or
824 the nonRepudiation bit must be set if the keyUsage extension is present.
826 =item B<S/MIME Encryption>
828 In addition to the common S/MIME tests the keyEncipherment bit must be set
829 if the keyUsage extension is present.
833 The extended key usage extension must be absent or include the "email
834 protection" OID. Netscape certificate type must be absent or must have the
835 S/MIME CA bit set: this is used as a work around if the basicConstraints
840 The keyUsage extension must be absent or it must have the CRL signing bit
843 =item B<CRL Signing CA>
845 The normal CA tests apply. Except in this case the basicConstraints extension
852 It is possible to produce invalid certificates or requests by specifying the
853 wrong private key, using unsuitable X.509 extensions,
854 or using inconsistent options in some cases: these should be checked.
856 There should be options to explicitly set such things as start and end
857 dates rather than an offset from the current time.
864 L<openssl-genrsa(1)>,
865 L<openssl-gendsa(1)>,
866 L<openssl-verify(1)>,
871 The hash algorithm used in the B<-subject_hash> and B<-issuer_hash> options
872 before OpenSSL 1.0.0 was based on the deprecated MD5 algorithm and the encoding
873 of the distinguished name. In OpenSSL 1.0.0 and later it is based on a canonical
874 version of the DN using SHA1. This means that any directories using the old
875 form must have their links rebuilt using L<openssl-rehash(1)> or similar.
877 The B<-signkey> option has been renamed to B<-key> in OpenSSL 3.0,
878 keeping the old name as an alias.
880 The B<-engine> option was deprecated in OpenSSL 3.0.
882 The B<-C> option was removed in OpenSSL 3.0.
886 Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved.
888 Licensed under the Apache License 2.0 (the "License"). You may not use
889 this file except in compliance with the License. You can obtain a copy
890 in the file LICENSE in the source distribution or at
891 L<https://www.openssl.org/source/license.html>.