2 {- OpenSSL::safe::output_do_not_edit_headers(); -}
6 openssl-x509 - Certificate display and signing command
12 [B<-inform> B<DER>|B<PEM>]
13 [B<-outform> B<DER>|B<PEM>]
14 [B<-keyform> B<DER>|B<PEM>|B<ENGINE>]
15 [B<-CAform> B<DER>|B<PEM>]
16 [B<-CAkeyform> B<DER>|B<PEM>|B<ENGINE>]
22 [B<-subject_hash_old>]
44 [B<-addreject> I<arg>]
54 [B<-CAkey> I<filename>]
56 [B<-CAserial> I<filename>]
60 [B<-force_pubkey> I<filename>]
63 [B<-ext> I<extensions>]
64 [B<-certopt> I<option>]
65 [B<-checkhost> I<host>]
66 [B<-checkemail> I<host>]
67 [B<-checkip> I<ipaddr>]
71 [B<-extfile> I<filename>]
72 [B<-extensions> I<section>]
73 [B<-sigopt> I<nm>:I<v>]
74 [B<-vfyopt> I<nm>:I<v>]
76 {- $OpenSSL::safe::opt_name_synopsis -}
77 {- $OpenSSL::safe::opt_r_synopsis -}
78 {- $OpenSSL::safe::opt_engine_synopsis -}
79 {- $OpenSSL::safe::opt_provider_synopsis -}
81 =for openssl ifdef engine subject_hash_old issuer_hash_old
85 This command is a multi-purposes certificate command. It can
86 be used to display certificate information, convert certificates to
87 various forms, sign certificate requests like a "mini CA" or edit
88 certificate trust settings.
90 Since there are a large number of options they will split up into
95 =head2 Input, Output, and General Purpose Options
101 Print out a usage message.
103 =item B<-inform> B<DER>|B<PEM>, B<-outform> B<DER>|B<PEM>
105 The input and formats; the default is B<PEM>.
106 See L<openssl(1)/Format Options> for details.
108 The input is normally an X.509 certificate, but this can change if other
109 options such as B<-req> are used.
111 =item B<-in> I<filename>
113 This specifies the input filename to read a certificate from or standard input
114 if this option is not specified.
116 =item B<-out> I<filename>
118 This specifies the output filename to write to or standard output by
124 This affects any signing or display option that uses a message
125 digest, such as the B<-fingerprint>, B<-signkey> and B<-CA> options.
126 Any digest supported by the L<openssl-dgst(1)> command can be used.
127 If not specified then SHA1 is used with B<-fingerprint> or
128 the default digest for the signing algorithm is used, typically SHA256.
130 =item B<-preserve_dates>
132 When signing a certificate, preserve the "notBefore" and "notAfter" dates
133 instead of adjusting them to current time and duration.
134 Cannot be used with the B<-days> option.
136 {- $OpenSSL::safe::opt_r_synopsis -}
138 {- $OpenSSL::safe::opt_engine_item -}
140 {- $OpenSSL::safe::opt_provider_item -}
144 =head2 Display Options
146 Note: the B<-alias> and B<-purpose> options are also display options
147 but are described in the L</Trust Settings> section.
153 Prints out the certificate in text form. Full details are output including the
154 public key, signature algorithms, issuer and subject names, serial number
155 any extensions present and any trust settings.
157 =item B<-ext> I<extensions>
159 Prints out the certificate extensions in text form. Extensions are specified
160 with a comma separated string, e.g., "subjectAltName,subjectKeyIdentifier".
161 See the L<x509v3_config(5)> manual page for the extension names.
163 =item B<-certopt> I<option>
165 Customise the output format used with B<-text>. The I<option> argument
166 can be a single option or multiple options separated by commas. The
167 B<-certopt> switch may be also be used more than once to set multiple
168 options. See the L</Text Options> section for more information.
170 =item B<-checkhost> I<host>
172 Check that the certificate matches the specified host.
174 =item B<-checkemail> I<email>
176 Check that the certificate matches the specified email address.
178 =item B<-checkip> I<ipaddr>
180 Check that the certificate matches the specified IP address.
184 This option prevents output of the encoded version of the certificate.
188 Outputs the certificate's SubjectPublicKeyInfo block in PEM format.
192 This option prints out the value of the modulus of the public key
193 contained in the certificate.
197 Outputs the certificate serial number.
199 =item B<-subject_hash>
201 Outputs the "hash" of the certificate subject name. This is used in OpenSSL to
202 form an index to allow certificates in a directory to be looked up by subject
205 =item B<-issuer_hash>
207 Outputs the "hash" of the certificate issuer name.
211 Outputs the OCSP hash values for the subject name and public key.
215 Synonym for "-subject_hash" for backward compatibility reasons.
217 =item B<-subject_hash_old>
219 Outputs the "hash" of the certificate subject name using the older algorithm
220 as used by OpenSSL before version 1.0.0.
222 =item B<-issuer_hash_old>
224 Outputs the "hash" of the certificate issuer name using the older algorithm
225 as used by OpenSSL before version 1.0.0.
229 Outputs the subject name.
233 Outputs the issuer name.
235 {- $OpenSSL::safe::opt_name_item -}
239 Outputs the email address(es) if any.
243 Outputs the OCSP responder address(es) if any.
247 Prints out the start date of the certificate, that is the notBefore date.
251 Prints out the expiry date of the certificate, that is the notAfter date.
255 Prints out the start and expiry dates of a certificate.
257 =item B<-checkend> I<arg>
259 Checks if the certificate expires within the next I<arg> seconds and exits
260 nonzero if yes it will expire or zero if not.
262 =item B<-fingerprint>
264 Calculates and outputs the digest of the DER encoded version of the entire
265 certificate (see digest options).
266 This is commonly called a "fingerprint". Because of the nature of message
267 digests, the fingerprint of a certificate is unique to that certificate and
268 two certificates with the same fingerprint can be considered to be the same.
272 This outputs the certificate in the form of a C source file.
276 =head2 Trust Settings
278 A B<trusted certificate> is an ordinary certificate which has several
279 additional pieces of information attached to it such as the permitted
280 and prohibited uses of the certificate and an "alias".
282 Normally when a certificate is being verified at least one certificate
283 must be "trusted". By default a trusted certificate must be stored
284 locally and must be a root CA: any certificate chain ending in this CA
285 is then usable for any purpose.
287 Trust settings currently are only used with a root CA. They allow a finer
288 control over the purposes the root CA can be used for. For example a CA
289 may be trusted for SSL client but not SSL server use.
291 See the description in L<openssl-verify(1)> for more information
292 on the meaning of trust settings.
294 Future versions of OpenSSL will recognize trust settings on any
295 certificate: not just root CAs.
302 Output a B<trusted> certificate rather than an ordinary. An ordinary
303 or trusted certificate can be input but by default an ordinary
304 certificate is output and any trust settings are discarded. With the
305 B<-trustout> option a trusted certificate is output. A trusted
306 certificate is automatically output if any trust settings are modified.
308 =item B<-setalias> I<arg>
310 Sets the alias of the certificate. This will allow the certificate
311 to be referred to using a nickname for example "Steve's Certificate".
315 Outputs the certificate alias, if any.
319 Clears all the permitted or trusted uses of the certificate.
323 Clears all the prohibited or rejected uses of the certificate.
325 =item B<-addtrust> I<arg>
327 Adds a trusted certificate use.
328 Any object name can be used here but currently only B<clientAuth> (SSL client
329 use), B<serverAuth> (SSL server use), B<emailProtection> (S/MIME email) and
330 B<anyExtendedKeyUsage> are used.
331 As of OpenSSL 1.1.0, the last of these blocks all purposes when rejected or
332 enables all purposes when trusted.
333 Other OpenSSL applications may define additional uses.
335 =item B<-addreject> I<arg>
337 Adds a prohibited use. It accepts the same values as the B<-addtrust>
342 This option performs tests on the certificate extensions and outputs
343 the results. For a more complete description see the
344 L</CERTIFICATE EXTENSIONS> section.
348 =head2 Signing Options
350 This command can be used to sign certificates and requests: it
351 can thus behave like a "mini CA".
355 =item B<-signkey> I<arg>
357 This option causes the input file to be self signed using the supplied
358 private key or engine. The private key's format is specified with the
361 It sets the issuer name to the subject name (i.e., makes it self-issued)
362 and changes the public key to the supplied value (unless overridden by
363 B<-force_pubkey>). It sets the validity start date to the current time
364 and the end date to a value determined by the B<-days> option.
365 It retains any certificate extensions unless the B<-clrext> option is supplied;
366 this includes, for example, any existing key identifier extensions.
370 Corrupt the signature before writing it; this can be useful
373 =item B<-sigopt> I<nm>:I<v>
375 Pass options to the signature algorithm during sign operations.
376 Names and values of these options are algorithm-specific.
378 =item B<-vfyopt> I<nm>:I<v>
380 Pass options to the signature algorithm during verify operations.
381 Names and values of these options are algorithm-specific.
383 =item B<-passin> I<arg>
385 The key password source. For more information about the format of I<arg>
386 see L<openssl(1)/Pass Phrase Options>.
390 Delete any extensions from a certificate. This option is used when a
391 certificate is being created from another certificate (for example with
392 the B<-signkey> or the B<-CA> options). Normally all extensions are
395 =item B<-keyform> B<DER>|B<PEM>|B<ENGINE>
397 The key format; the default is B<PEM>.
398 See L<openssl(1)/Format Options> for details.
400 =item B<-CAform> B<DER>|B<PEM>, B<-CAkeyform> B<DER>|B<PEM>|B<ENGINE>
402 The format for the CA certificate and key; the default is B<PEM>.
403 See L<openssl(1)/Format Options> for details.
405 =item B<-days> I<arg>
407 Specifies the number of days to make a certificate valid for. The default
408 is 30 days. Cannot be used with the B<-preserve_dates> option.
412 Converts a certificate into a certificate request. The B<-signkey> option
413 is used to pass the required private key.
417 By default a certificate is expected on input. With this option a
418 certificate request is expected instead.
420 =item B<-set_serial> I<n>
422 Specifies the serial number to use. This option can be used with either
423 the B<-signkey> or B<-CA> options. If used in conjunction with the B<-CA>
424 option the serial number file (as specified by the B<-CAserial> or
425 B<-CAcreateserial> options) is not used.
427 The serial number can be decimal or hex (if preceded by C<0x>).
429 =item B<-CA> I<filename>
431 Specifies the CA certificate to be used for signing. When this option is
432 present, this command behaves like a "mini CA". The input file is signed by
433 this CA using this option: that is its issuer name is set to the subject name
434 of the CA and it is digitally signed using the CAs private key.
436 This option is normally combined with the B<-req> option. Without the
437 B<-req> option the input is a certificate which must be self signed.
439 =item B<-CAkey> I<filename>
441 Sets the CA private key to sign a certificate with. If this option is
442 not specified then it is assumed that the CA private key is present in
443 the CA certificate file.
445 =item B<-CAserial> I<filename>
447 Sets the CA serial number file to use.
449 When the B<-CA> option is used to sign a certificate it uses a serial
450 number specified in a file. This file consists of one line containing
451 an even number of hex digits with the serial number to use. After each
452 use the serial number is incremented and written out to the file again.
454 The default filename consists of the CA certificate file base name with
455 F<.srl> appended. For example if the CA certificate file is called
456 F<mycacert.pem> it expects to find a serial number file called
459 =item B<-CAcreateserial>
461 With this option the CA serial number file is created if it does not exist:
462 it will contain the serial number "02" and the certificate being signed will
463 have the 1 as its serial number. If the B<-CA> option is specified
464 and the serial number file does not exist a random number is generated;
465 this is the recommended practice.
467 =item B<-extfile> I<filename>
469 File containing certificate extensions to use. If not specified then
470 no extensions are added to the certificate.
472 =item B<-extensions> I<section>
474 The section to add certificate extensions from. If this option is not
475 specified then the extensions should either be contained in the unnamed
476 (default) section or the default section should contain a variable called
477 "extensions" which contains the section to use. See the
478 L<x509v3_config(5)> manual page for details of the
479 extension section format.
483 Generate a certificate from scratch, not using an input certificate
484 or certificate request. So the B<-in> option must not be used in this case.
485 Instead, the B<-subj> and <-force_pubkey> options need to be given.
487 =item B<-next_serial>
489 Set the serial to be one more than the number in the certificate.
493 Do not generate or output a certificate.
495 =item B<-force_pubkey> I<filename>
497 When a certificate is created set its public key to the key in I<filename>
498 instead of the key contained in the input or given with the B<-signkey> option.
500 This option is useful for creating self-issued certificates that are not
501 self-signed, for instance when the key cannot be used for signing, such as DH.
502 It can also be used in conjunction with b<-new> and B<-subj> to directly
503 generate a certificate containing any desired public key.
505 The format of the key file can be specified using the B<-keyform> option.
507 =item B<-subj> I<arg>
509 When a certificate is created set its subject name to the given value.
510 The arg must be formatted as C</type0=value0/type1=value1/type2=...>.
511 Keyword characters may be escaped by \ (backslash), and whitespace is retained.
512 Empty values are permitted, but the corresponding type will not be included
513 in the certificate. Giving a single C</> will lead to an empty sequence of RDNs
516 Unless the B<-CA> option is given the issuer is set to the same value.
518 This option can be used in conjunction with the B<-force_pubkey> option
519 to create a certificate even without providing an input certificate
520 or certificate request.
526 As well as customising the name output format, it is also possible to
527 customise the actual fields printed using the B<certopt> options when
528 the B<text> option is present. The default behaviour is to print all fields.
534 Use the old format. This is equivalent to specifying no output options at all.
538 Don't print header information: that is the lines saying "Certificate"
543 Don't print out the version number.
547 Don't print out the serial number.
551 Don't print out the signature algorithm used.
555 Don't print the validity, that is the B<notBefore> and B<notAfter> fields.
559 Don't print out the subject name.
563 Don't print out the issuer name.
567 Don't print out the public key.
571 Don't give a hexadecimal dump of the certificate signature.
575 Don't print out certificate trust information.
577 =item B<no_extensions>
579 Don't print out any X509V3 extensions.
583 Retain default extension behaviour: attempt to print out unsupported
584 certificate extensions.
588 Print an error message for unsupported certificate extensions.
592 ASN1 parse unsupported extensions.
596 Hex dump unsupported extensions.
600 The value used by L<openssl-ca(1)>, equivalent to B<no_issuer>, B<no_pubkey>,
601 B<no_header>, and B<no_version>.
607 Note: in these examples the '\' means the example should be all on one
610 Display the contents of a certificate:
612 openssl x509 -in cert.pem -noout -text
614 Display the "Subject Alternative Name" extension of a certificate:
616 openssl x509 -in cert.pem -noout -ext subjectAltName
618 Display more extensions of a certificate:
620 openssl x509 -in cert.pem -noout -ext subjectAltName,nsCertType
622 Display the certificate serial number:
624 openssl x509 -in cert.pem -noout -serial
626 Display the certificate subject name:
628 openssl x509 -in cert.pem -noout -subject
630 Display the certificate subject name in RFC2253 form:
632 openssl x509 -in cert.pem -noout -subject -nameopt RFC2253
634 Display the certificate subject name in oneline form on a terminal
637 openssl x509 -in cert.pem -noout -subject -nameopt oneline,-esc_msb
639 Display the certificate SHA1 fingerprint:
641 openssl x509 -sha1 -in cert.pem -noout -fingerprint
643 Convert a certificate from PEM to DER format:
645 openssl x509 -in cert.pem -inform PEM -out cert.der -outform DER
647 Convert a certificate to a certificate request:
649 openssl x509 -x509toreq -in cert.pem -out req.pem -signkey key.pem
651 Convert a certificate request into a self signed certificate using
654 openssl x509 -req -in careq.pem -extfile openssl.cnf -extensions v3_ca \
655 -signkey key.pem -out cacert.pem
657 Sign a certificate request using the CA certificate above and add user
658 certificate extensions:
660 openssl x509 -req -in req.pem -extfile openssl.cnf -extensions v3_usr \
661 -CA cacert.pem -CAkey key.pem -CAcreateserial
664 Set a certificate to be trusted for SSL client use and change set its alias to
667 openssl x509 -in cert.pem -addtrust clientAuth \
668 -setalias "Steve's Class 1 CA" -out trust.pem
672 The conversion to UTF8 format used with the name options assumes that
673 T61Strings use the ISO8859-1 character set. This is wrong but Netscape
674 and MSIE do this as do many certificates. So although this is incorrect
675 it is more likely to display the majority of certificates correctly.
677 The B<-email> option searches the subject name and the subject alternative
678 name extension. Only unique email addresses will be printed out: it will
679 not print the same address more than once.
681 =head1 CERTIFICATE EXTENSIONS
683 The B<-purpose> option checks the certificate extensions and determines
684 what the certificate can be used for. The actual checks done are rather
685 complex and include various hacks and workarounds to handle broken
686 certificates and software.
688 The same code is used when verifying untrusted certificates in chains
689 so this section is useful if a chain is rejected by the verify code.
691 The basicConstraints extension CA flag is used to determine whether the
692 certificate can be used as a CA. If the CA flag is true then it is a CA,
693 if the CA flag is false then it is not a CA. B<All> CAs should have the
696 If the basicConstraints extension is absent then the certificate is
697 considered to be a "possible CA" other extensions are checked according
698 to the intended use of the certificate. A warning is given in this case
699 because the certificate should really not be regarded as a CA: however
700 it is allowed to be a CA to work around some broken software.
702 If the certificate is a V1 certificate (and thus has no extensions) and
703 it is self signed it is also assumed to be a CA but a warning is again
704 given: this is to work around the problem of Verisign roots which are V1
705 self signed certificates.
707 If the keyUsage extension is present then additional restraints are
708 made on the uses of the certificate. A CA certificate B<must> have the
709 keyCertSign bit set if the keyUsage extension is present.
711 The extended key usage extension places additional restrictions on the
712 certificate uses. If this extension is present (whether critical or not)
713 the key can only be used for the purposes specified.
715 A complete description of each test is given below. The comments about
716 basicConstraints and keyUsage and V1 certificates above apply to B<all>
724 The extended key usage extension must be absent or include the "web client
725 authentication" OID. keyUsage must be absent or it must have the
726 digitalSignature bit set. Netscape certificate type must be absent or it must
727 have the SSL client bit set.
729 =item B<SSL Client CA>
731 The extended key usage extension must be absent or include the "web client
732 authentication" OID. Netscape certificate type must be absent or it must have
733 the SSL CA bit set: this is used as a work around if the basicConstraints
738 The extended key usage extension must be absent or include the "web server
739 authentication" and/or one of the SGC OIDs. keyUsage must be absent or it
740 must have the digitalSignature, the keyEncipherment set or both bits set.
741 Netscape certificate type must be absent or have the SSL server bit set.
743 =item B<SSL Server CA>
745 The extended key usage extension must be absent or include the "web server
746 authentication" and/or one of the SGC OIDs. Netscape certificate type must
747 be absent or the SSL CA bit must be set: this is used as a work around if the
748 basicConstraints extension is absent.
750 =item B<Netscape SSL Server>
752 For Netscape SSL clients to connect to an SSL server it must have the
753 keyEncipherment bit set if the keyUsage extension is present. This isn't
754 always valid because some cipher suites use the key for digital signing.
755 Otherwise it is the same as a normal SSL server.
757 =item B<Common S/MIME Client Tests>
759 The extended key usage extension must be absent or include the "email
760 protection" OID. Netscape certificate type must be absent or should have the
761 S/MIME bit set. If the S/MIME bit is not set in Netscape certificate type
762 then the SSL client bit is tolerated as an alternative but a warning is shown:
763 this is because some Verisign certificates don't set the S/MIME bit.
765 =item B<S/MIME Signing>
767 In addition to the common S/MIME client tests the digitalSignature bit or
768 the nonRepudiation bit must be set if the keyUsage extension is present.
770 =item B<S/MIME Encryption>
772 In addition to the common S/MIME tests the keyEncipherment bit must be set
773 if the keyUsage extension is present.
777 The extended key usage extension must be absent or include the "email
778 protection" OID. Netscape certificate type must be absent or must have the
779 S/MIME CA bit set: this is used as a work around if the basicConstraints
784 The keyUsage extension must be absent or it must have the CRL signing bit
787 =item B<CRL Signing CA>
789 The normal CA tests apply. Except in this case the basicConstraints extension
796 Extensions in certificates are not transferred to certificate requests and
799 It is possible to produce invalid certificates or requests by specifying the
800 wrong private key or using inconsistent options in some cases: these should
803 There should be options to explicitly set such things as start and end
804 dates rather than an offset from the current time.
811 L<openssl-genrsa(1)>,
812 L<openssl-gendsa(1)>,
813 L<openssl-verify(1)>,
818 The hash algorithm used in the B<-subject_hash> and B<-issuer_hash> options
819 before OpenSSL 1.0.0 was based on the deprecated MD5 algorithm and the encoding
820 of the distinguished name. In OpenSSL 1.0.0 and later it is based on a canonical
821 version of the DN using SHA1. This means that any directories using the old
822 form must have their links rebuilt using L<openssl-rehash(1)> or similar.
826 Copyright 2000-2020 The OpenSSL Project Authors. All Rights Reserved.
828 Licensed under the Apache License 2.0 (the "License"). You may not use
829 this file except in compliance with the License. You can obtain a copy
830 in the file LICENSE in the source distribution or at
831 L<https://www.openssl.org/source/license.html>.