2 {- OpenSSL::safe::output_do_not_edit_headers(); -}
6 openssl-x509 - Certificate display and signing utility
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>]
48 [B<-signkey> I<filename>]
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>]
75 {- $OpenSSL::safe::opt_name_synopsis -}
76 {- $OpenSSL::safe::opt_r_synopsis -}
77 {- $OpenSSL::safe::opt_engine_synopsis -}
79 =for openssl ifdef engine subject_hash_old issuer_hash_old
83 This command is a multi purpose certificate utility. It can
84 be used to display certificate information, convert certificates to
85 various forms, sign certificate requests like a "mini CA" or edit
86 certificate trust settings.
88 Since there are a large number of options they will split up into
93 =head2 Input, Output, and General Purpose Options
99 Print out a usage message.
101 =item B<-inform> B<DER>|B<PEM>, B<-outform> B<DER>|B<PEM>
103 The input and formats; the default is B<PEM>.
104 See L<openssl(1)/Format Options> for details.
106 The input is normally an X.509 certificate, but this can change if other
107 options such as B<-req> are used.
109 =item B<-in> I<filename>
111 This specifies the input filename to read a certificate from or standard input
112 if this option is not specified.
114 =item B<-out> I<filename>
116 This specifies the output filename to write to or standard output by
122 This affects any signing or display option that uses a message
123 digest, such as the B<-fingerprint>, B<-signkey> and B<-CA> options.
124 Any digest supported by the L<openssl-dgst(1)> command can be used.
125 If not specified then SHA1 is used with B<-fingerprint> or
126 the default digest for the signing algorithm is used, typically SHA256.
128 =item B<-preserve_dates>
130 When signing a certificate, preserve the "notBefore" and "notAfter" dates
131 instead of adjusting them to current time and duration.
132 Cannot be used with the B<-days> option.
134 {- $OpenSSL::safe::opt_r_synopsis -}
136 {- $OpenSSL::safe::opt_engine_item -}
140 =head2 Display Options
142 Note: the B<-alias> and B<-purpose> options are also display options
143 but are described in the L</Trust Settings> section.
149 Prints out the certificate in text form. Full details are output including the
150 public key, signature algorithms, issuer and subject names, serial number
151 any extensions present and any trust settings.
153 =item B<-ext> I<extensions>
155 Prints out the certificate extensions in text form. Extensions are specified
156 with a comma separated string, e.g., "subjectAltName,subjectKeyIdentifier".
157 See the L<x509v3_config(5)> manual page for the extension names.
159 =item B<-certopt> I<option>
161 Customise the output format used with B<-text>. The I<option> argument
162 can be a single option or multiple options separated by commas. The
163 B<-certopt> switch may be also be used more than once to set multiple
164 options. See the L</Text Options> section for more information.
166 =item B<-checkhost> I<host>
168 Check that the certificate matches the specified host.
170 =item B<-checkemail> I<email>
172 Check that the certificate matches the specified email address.
174 =item B<-checkip> I<ipaddr>
176 Check that the certificate matches the specified IP address.
180 This option prevents output of the encoded version of the certificate.
184 Outputs the certificate's SubjectPublicKeyInfo block in PEM format.
188 This option prints out the value of the modulus of the public key
189 contained in the certificate.
193 Outputs the certificate serial number.
195 =item B<-subject_hash>
197 Outputs the "hash" of the certificate subject name. This is used in OpenSSL to
198 form an index to allow certificates in a directory to be looked up by subject
201 =item B<-issuer_hash>
203 Outputs the "hash" of the certificate issuer name.
207 Outputs the OCSP hash values for the subject name and public key.
211 Synonym for "-subject_hash" for backward compatibility reasons.
213 =item B<-subject_hash_old>
215 Outputs the "hash" of the certificate subject name using the older algorithm
216 as used by OpenSSL before version 1.0.0.
218 =item B<-issuer_hash_old>
220 Outputs the "hash" of the certificate issuer name using the older algorithm
221 as used by OpenSSL before version 1.0.0.
225 Outputs the subject name.
229 Outputs the issuer name.
231 {- $OpenSSL::safe::opt_name_item -}
235 Outputs the email address(es) if any.
239 Outputs the OCSP responder address(es) if any.
243 Prints out the start date of the certificate, that is the notBefore date.
247 Prints out the expiry date of the certificate, that is the notAfter date.
251 Prints out the start and expiry dates of a certificate.
253 =item B<-checkend> I<arg>
255 Checks if the certificate expires within the next I<arg> seconds and exits
256 nonzero if yes it will expire or zero if not.
258 =item B<-fingerprint>
260 Calculates and outputs the digest of the DER encoded version of the entire
261 certificate (see digest options).
262 This is commonly called a "fingerprint". Because of the nature of message
263 digests, the fingerprint of a certificate is unique to that certificate and
264 two certificates with the same fingerprint can be considered to be the same.
268 This outputs the certificate in the form of a C source file.
272 =head2 Trust Settings
274 A B<trusted certificate> is an ordinary certificate which has several
275 additional pieces of information attached to it such as the permitted
276 and prohibited uses of the certificate and an "alias".
278 Normally when a certificate is being verified at least one certificate
279 must be "trusted". By default a trusted certificate must be stored
280 locally and must be a root CA: any certificate chain ending in this CA
281 is then usable for any purpose.
283 Trust settings currently are only used with a root CA. They allow a finer
284 control over the purposes the root CA can be used for. For example a CA
285 may be trusted for SSL client but not SSL server use.
287 See the description in L<openssl-verify(1)> for more information
288 on the meaning of trust settings.
290 Future versions of OpenSSL will recognize trust settings on any
291 certificate: not just root CAs.
298 Output a B<trusted> certificate rather than an ordinary. An ordinary
299 or trusted certificate can be input but by default an ordinary
300 certificate is output and any trust settings are discarded. With the
301 B<-trustout> option a trusted certificate is output. A trusted
302 certificate is automatically output if any trust settings are modified.
304 =item B<-setalias> I<arg>
306 Sets the alias of the certificate. This will allow the certificate
307 to be referred to using a nickname for example "Steve's Certificate".
311 Outputs the certificate alias, if any.
315 Clears all the permitted or trusted uses of the certificate.
319 Clears all the prohibited or rejected uses of the certificate.
321 =item B<-addtrust> I<arg>
323 Adds a trusted certificate use.
324 Any object name can be used here but currently only B<clientAuth> (SSL client
325 use), B<serverAuth> (SSL server use), B<emailProtection> (S/MIME email) and
326 B<anyExtendedKeyUsage> are used.
327 As of OpenSSL 1.1.0, the last of these blocks all purposes when rejected or
328 enables all purposes when trusted.
329 Other OpenSSL applications may define additional uses.
331 =item B<-addreject> I<arg>
333 Adds a prohibited use. It accepts the same values as the B<-addtrust>
338 This option performs tests on the certificate extensions and outputs
339 the results. For a more complete description see the
340 L</CERTIFICATE EXTENSIONS> section.
344 =head2 Signing Options
346 This command can be used to sign certificates and requests: it
347 can thus behave like a "mini CA".
351 =item B<-signkey> I<filename>
353 This option causes the input file to be self signed using the supplied
356 It sets the issuer name to the subject name (i.e., makes it self-issued)
357 and changes the public key to the supplied value (unless overridden by
358 B<-force_pubkey>). It sets the validity start date to the current time
359 and the end date to a value determined by the B<-days> option.
360 It retains any certificate extensions unless the B<-clrext> option is supplied;
361 this includes, for example, any existing key identifier extensions.
365 Corrupt the signature before writing it; this can be useful
368 =item B<-sigopt> I<nm>:I<v>
370 Pass options to the signature algorithm during sign or verify operations.
371 Names and values of these options are algorithm-specific.
373 =item B<-passin> I<arg>
375 The key password source. For more information about the format of I<arg>
376 see L<openssl(1)/Pass Phrase Options>.
380 Delete any extensions from a certificate. This option is used when a
381 certificate is being created from another certificate (for example with
382 the B<-signkey> or the B<-CA> options). Normally all extensions are
385 =item B<-keyform> B<DER>|B<PEM>
387 The key format; the default is B<PEM>.
388 See L<openssl(1)/Format Options> for details.
390 =item B<-CAform> B<DER>|B<PEM>, B<-CAkeyform> B<DER>|B<PEM>
392 The format for the CA certificate and key; the default is B<PEM>.
393 See L<openssl(1)/Format Options> for details.
395 =item B<-days> I<arg>
397 Specifies the number of days to make a certificate valid for. The default
398 is 30 days. Cannot be used with the B<-preserve_dates> option.
402 Converts a certificate into a certificate request. The B<-signkey> option
403 is used to pass the required private key.
407 By default a certificate is expected on input. With this option a
408 certificate request is expected instead.
410 =item B<-set_serial> I<n>
412 Specifies the serial number to use. This option can be used with either
413 the B<-signkey> or B<-CA> options. If used in conjunction with the B<-CA>
414 option the serial number file (as specified by the B<-CAserial> or
415 B<-CAcreateserial> options) is not used.
417 The serial number can be decimal or hex (if preceded by C<0x>).
419 =item B<-CA> I<filename>
421 Specifies the CA certificate to be used for signing. When this option is
422 present, this command behaves like a "mini CA". The input file is signed by
423 this CA using this option: that is its issuer name is set to the subject name
424 of the CA and it is digitally signed using the CAs private key.
426 This option is normally combined with the B<-req> option. Without the
427 B<-req> option the input is a certificate which must be self signed.
429 =item B<-CAkey> I<filename>
431 Sets the CA private key to sign a certificate with. If this option is
432 not specified then it is assumed that the CA private key is present in
433 the CA certificate file.
435 =item B<-CAserial> I<filename>
437 Sets the CA serial number file to use.
439 When the B<-CA> option is used to sign a certificate it uses a serial
440 number specified in a file. This file consists of one line containing
441 an even number of hex digits with the serial number to use. After each
442 use the serial number is incremented and written out to the file again.
444 The default filename consists of the CA certificate file base name with
445 F<.srl> appended. For example if the CA certificate file is called
446 F<mycacert.pem> it expects to find a serial number file called
449 =item B<-CAcreateserial>
451 With this option the CA serial number file is created if it does not exist:
452 it will contain the serial number "02" and the certificate being signed will
453 have the 1 as its serial number. If the B<-CA> option is specified
454 and the serial number file does not exist a random number is generated;
455 this is the recommended practice.
457 =item B<-extfile> I<filename>
459 File containing certificate extensions to use. If not specified then
460 no extensions are added to the certificate.
462 =item B<-extensions> I<section>
464 The section to add certificate extensions from. If this option is not
465 specified then the extensions should either be contained in the unnamed
466 (default) section or the default section should contain a variable called
467 "extensions" which contains the section to use. See the
468 L<x509v3_config(5)> manual page for details of the
469 extension section format.
473 Generate a certificate from scratch, not using an input certificate
474 or certificate request. So the B<-in> option must not be used in this case.
475 Instead, the B<-subj> and <-force_pubkey> options need to be given.
477 =item B<-next_serial>
479 Set the serial to be one more than the number in the certificate.
483 Do not generate or output a certificate.
485 =item B<-force_pubkey> I<filename>
487 When a certificate is created set its public key to the key in I<filename>
488 instead of the key contained in the input or given with the B<-signkey> option.
490 This option is useful for creating self-issued certificates that are not
491 self-signed, for instance when the key cannot be used for signing, such as DH.
492 It can also be used in conjunction with b<-new> and B<-subj> to directly
493 generate a certificate containing any desired public key.
495 The format of the key file can be specified using the B<-keyform> option.
497 =item B<-subj> I<arg>
499 When a certificate is created set its subject name to the given value.
500 The arg must be formatted as C</type0=value0/type1=value1/type2=...>.
501 Keyword characters may be escaped by \ (backslash), and whitespace is retained.
502 Empty values are permitted, but the corresponding type will not be included
503 in the certificate. Giving a single C</> will lead to an empty sequence of RDNs
506 Unless the B<-CA> option is given the issuer is set to the same value.
508 This option can be used in conjunction with the B<-force_pubkey> option
509 to create a certificate even without providing an input certificate
510 or certificate request.
516 As well as customising the name output format, it is also possible to
517 customise the actual fields printed using the B<certopt> options when
518 the B<text> option is present. The default behaviour is to print all fields.
524 Use the old format. This is equivalent to specifying no output options at all.
528 Don't print header information: that is the lines saying "Certificate"
533 Don't print out the version number.
537 Don't print out the serial number.
541 Don't print out the signature algorithm used.
545 Don't print the validity, that is the B<notBefore> and B<notAfter> fields.
549 Don't print out the subject name.
553 Don't print out the issuer name.
557 Don't print out the public key.
561 Don't give a hexadecimal dump of the certificate signature.
565 Don't print out certificate trust information.
567 =item B<no_extensions>
569 Don't print out any X509V3 extensions.
573 Retain default extension behaviour: attempt to print out unsupported
574 certificate extensions.
578 Print an error message for unsupported certificate extensions.
582 ASN1 parse unsupported extensions.
586 Hex dump unsupported extensions.
590 The value used by L<openssl-ca(1)>, equivalent to B<no_issuer>, B<no_pubkey>,
591 B<no_header>, and B<no_version>.
597 Note: in these examples the '\' means the example should be all on one
600 Display the contents of a certificate:
602 openssl x509 -in cert.pem -noout -text
604 Display the "Subject Alternative Name" extension of a certificate:
606 openssl x509 -in cert.pem -noout -ext subjectAltName
608 Display more extensions of a certificate:
610 openssl x509 -in cert.pem -noout -ext subjectAltName,nsCertType
612 Display the certificate serial number:
614 openssl x509 -in cert.pem -noout -serial
616 Display the certificate subject name:
618 openssl x509 -in cert.pem -noout -subject
620 Display the certificate subject name in RFC2253 form:
622 openssl x509 -in cert.pem -noout -subject -nameopt RFC2253
624 Display the certificate subject name in oneline form on a terminal
627 openssl x509 -in cert.pem -noout -subject -nameopt oneline,-esc_msb
629 Display the certificate SHA1 fingerprint:
631 openssl x509 -sha1 -in cert.pem -noout -fingerprint
633 Convert a certificate from PEM to DER format:
635 openssl x509 -in cert.pem -inform PEM -out cert.der -outform DER
637 Convert a certificate to a certificate request:
639 openssl x509 -x509toreq -in cert.pem -out req.pem -signkey key.pem
641 Convert a certificate request into a self signed certificate using
644 openssl x509 -req -in careq.pem -extfile openssl.cnf -extensions v3_ca \
645 -signkey key.pem -out cacert.pem
647 Sign a certificate request using the CA certificate above and add user
648 certificate extensions:
650 openssl x509 -req -in req.pem -extfile openssl.cnf -extensions v3_usr \
651 -CA cacert.pem -CAkey key.pem -CAcreateserial
654 Set a certificate to be trusted for SSL client use and change set its alias to
657 openssl x509 -in cert.pem -addtrust clientAuth \
658 -setalias "Steve's Class 1 CA" -out trust.pem
662 The conversion to UTF8 format used with the name options assumes that
663 T61Strings use the ISO8859-1 character set. This is wrong but Netscape
664 and MSIE do this as do many certificates. So although this is incorrect
665 it is more likely to display the majority of certificates correctly.
667 The B<-email> option searches the subject name and the subject alternative
668 name extension. Only unique email addresses will be printed out: it will
669 not print the same address more than once.
671 =head1 CERTIFICATE EXTENSIONS
673 The B<-purpose> option checks the certificate extensions and determines
674 what the certificate can be used for. The actual checks done are rather
675 complex and include various hacks and workarounds to handle broken
676 certificates and software.
678 The same code is used when verifying untrusted certificates in chains
679 so this section is useful if a chain is rejected by the verify code.
681 The basicConstraints extension CA flag is used to determine whether the
682 certificate can be used as a CA. If the CA flag is true then it is a CA,
683 if the CA flag is false then it is not a CA. B<All> CAs should have the
686 If the basicConstraints extension is absent then the certificate is
687 considered to be a "possible CA" other extensions are checked according
688 to the intended use of the certificate. A warning is given in this case
689 because the certificate should really not be regarded as a CA: however
690 it is allowed to be a CA to work around some broken software.
692 If the certificate is a V1 certificate (and thus has no extensions) and
693 it is self signed it is also assumed to be a CA but a warning is again
694 given: this is to work around the problem of Verisign roots which are V1
695 self signed certificates.
697 If the keyUsage extension is present then additional restraints are
698 made on the uses of the certificate. A CA certificate B<must> have the
699 keyCertSign bit set if the keyUsage extension is present.
701 The extended key usage extension places additional restrictions on the
702 certificate uses. If this extension is present (whether critical or not)
703 the key can only be used for the purposes specified.
705 A complete description of each test is given below. The comments about
706 basicConstraints and keyUsage and V1 certificates above apply to B<all>
714 The extended key usage extension must be absent or include the "web client
715 authentication" OID. keyUsage must be absent or it must have the
716 digitalSignature bit set. Netscape certificate type must be absent or it must
717 have the SSL client bit set.
719 =item B<SSL Client CA>
721 The extended key usage extension must be absent or include the "web client
722 authentication" OID. Netscape certificate type must be absent or it must have
723 the SSL CA bit set: this is used as a work around if the basicConstraints
728 The extended key usage extension must be absent or include the "web server
729 authentication" and/or one of the SGC OIDs. keyUsage must be absent or it
730 must have the digitalSignature, the keyEncipherment set or both bits set.
731 Netscape certificate type must be absent or have the SSL server bit set.
733 =item B<SSL Server CA>
735 The extended key usage extension must be absent or include the "web server
736 authentication" and/or one of the SGC OIDs. Netscape certificate type must
737 be absent or the SSL CA bit must be set: this is used as a work around if the
738 basicConstraints extension is absent.
740 =item B<Netscape SSL Server>
742 For Netscape SSL clients to connect to an SSL server it must have the
743 keyEncipherment bit set if the keyUsage extension is present. This isn't
744 always valid because some cipher suites use the key for digital signing.
745 Otherwise it is the same as a normal SSL server.
747 =item B<Common S/MIME Client Tests>
749 The extended key usage extension must be absent or include the "email
750 protection" OID. Netscape certificate type must be absent or should have the
751 S/MIME bit set. If the S/MIME bit is not set in Netscape certificate type
752 then the SSL client bit is tolerated as an alternative but a warning is shown:
753 this is because some Verisign certificates don't set the S/MIME bit.
755 =item B<S/MIME Signing>
757 In addition to the common S/MIME client tests the digitalSignature bit or
758 the nonRepudiation bit must be set if the keyUsage extension is present.
760 =item B<S/MIME Encryption>
762 In addition to the common S/MIME tests the keyEncipherment bit must be set
763 if the keyUsage extension is present.
767 The extended key usage extension must be absent or include the "email
768 protection" OID. Netscape certificate type must be absent or must have the
769 S/MIME CA bit set: this is used as a work around if the basicConstraints
774 The keyUsage extension must be absent or it must have the CRL signing bit
777 =item B<CRL Signing CA>
779 The normal CA tests apply. Except in this case the basicConstraints extension
786 Extensions in certificates are not transferred to certificate requests and
789 It is possible to produce invalid certificates or requests by specifying the
790 wrong private key or using inconsistent options in some cases: these should
793 There should be options to explicitly set such things as start and end
794 dates rather than an offset from the current time.
801 L<openssl-genrsa(1)>,
802 L<openssl-gendsa(1)>,
803 L<openssl-verify(1)>,
808 The hash algorithm used in the B<-subject_hash> and B<-issuer_hash> options
809 before OpenSSL 1.0.0 was based on the deprecated MD5 algorithm and the encoding
810 of the distinguished name. In OpenSSL 1.0.0 and later it is based on a canonical
811 version of the DN using SHA1. This means that any directories using the old
812 form must have their links rebuilt using L<openssl-rehash(1)> or similar.
816 Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
818 Licensed under the Apache License 2.0 (the "License"). You may not use
819 this file except in compliance with the License. You can obtain a copy
820 in the file LICENSE in the source distribution or at
821 L<https://www.openssl.org/source/license.html>.