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authorJung-uk Kim <jkim@FreeBSD.org>2018-09-13 19:18:07 +0000
committerJung-uk Kim <jkim@FreeBSD.org>2018-09-13 19:18:07 +0000
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tree9794cf7720d75938ed0ea4f499c0dcd4b6eacdda /doc/man1/ca.pod
parent02be298e504b8554caca6dc85af450e1ea44d19d (diff)
downloadsrc-a43ce912fc025d11e1395506111f75fc194d7ba5.tar.gz
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Import OpenSSL 1.1.1.vendor/openssl/1.1.1
Notes
Notes: svn path=/vendor-crypto/openssl/dist/; revision=338658 svn path=/vendor-crypto/openssl/1.1.1/; revision=338659; tag=vendor/openssl/1.1.1
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+=pod
+
+=head1 NAME
+
+openssl-ca,
+ca - sample minimal CA application
+
+=head1 SYNOPSIS
+
+B<openssl> B<ca>
+[B<-help>]
+[B<-verbose>]
+[B<-config filename>]
+[B<-name section>]
+[B<-gencrl>]
+[B<-revoke file>]
+[B<-valid file>]
+[B<-status serial>]
+[B<-updatedb>]
+[B<-crl_reason reason>]
+[B<-crl_hold instruction>]
+[B<-crl_compromise time>]
+[B<-crl_CA_compromise time>]
+[B<-crldays days>]
+[B<-crlhours hours>]
+[B<-crlexts section>]
+[B<-startdate date>]
+[B<-enddate date>]
+[B<-days arg>]
+[B<-md arg>]
+[B<-policy arg>]
+[B<-keyfile arg>]
+[B<-keyform PEM|DER>]
+[B<-key arg>]
+[B<-passin arg>]
+[B<-cert file>]
+[B<-selfsign>]
+[B<-in file>]
+[B<-out file>]
+[B<-notext>]
+[B<-outdir dir>]
+[B<-infiles>]
+[B<-spkac file>]
+[B<-ss_cert file>]
+[B<-preserveDN>]
+[B<-noemailDN>]
+[B<-batch>]
+[B<-msie_hack>]
+[B<-extensions section>]
+[B<-extfile section>]
+[B<-engine id>]
+[B<-subj arg>]
+[B<-utf8>]
+[B<-create_serial>]
+[B<-rand_serial>]
+[B<-multivalue-rdn>]
+[B<-rand file...>]
+[B<-writerand file>]
+
+=head1 DESCRIPTION
+
+The B<ca> command is a minimal CA application. It can be used
+to sign certificate requests in a variety of forms and generate
+CRLs it also maintains a text database of issued certificates
+and their status.
+
+The options descriptions will be divided into each purpose.
+
+=head1 OPTIONS
+
+=over 4
+
+=item B<-help>
+
+Print out a usage message.
+
+=item B<-verbose>
+
+This prints extra details about the operations being performed.
+
+=item B<-config filename>
+
+Specifies the configuration file to use.
+Optional; for a description of the default value,
+see L<openssl(1)/COMMAND SUMMARY>.
+
+=item B<-name section>
+
+Specifies the configuration file section to use (overrides
+B<default_ca> in the B<ca> section).
+
+=item B<-in filename>
+
+An input filename containing a single certificate request to be
+signed by the CA.
+
+=item B<-ss_cert filename>
+
+A single self-signed certificate to be signed by the CA.
+
+=item B<-spkac filename>
+
+A file containing a single Netscape signed public key and challenge
+and additional field values to be signed by the CA. See the B<SPKAC FORMAT>
+section for information on the required input and output format.
+
+=item B<-infiles>
+
+If present this should be the last option, all subsequent arguments
+are taken as the names of files containing certificate requests.
+
+=item B<-out filename>
+
+The output file to output certificates to. The default is standard
+output. The certificate details will also be printed out to this
+file in PEM format (except that B<-spkac> outputs DER format).
+
+=item B<-outdir directory>
+
+The directory to output certificates to. The certificate will be
+written to a filename consisting of the serial number in hex with
+".pem" appended.
+
+=item B<-cert>
+
+The CA certificate file.
+
+=item B<-keyfile filename>
+
+The private key to sign requests with.
+
+=item B<-keyform PEM|DER>
+
+The format of the data in the private key file.
+The default is PEM.
+
+=item B<-key password>
+
+The password used to encrypt the private key. Since on some
+systems the command line arguments are visible (e.g. Unix with
+the 'ps' utility) this option should be used with caution.
+
+=item B<-selfsign>
+
+Indicates the issued certificates are to be signed with the key
+the certificate requests were signed with (given with B<-keyfile>).
+Certificate requests signed with a different key are ignored. If
+B<-spkac>, B<-ss_cert> or B<-gencrl> are given, B<-selfsign> is
+ignored.
+
+A consequence of using B<-selfsign> is that the self-signed
+certificate appears among the entries in the certificate database
+(see the configuration option B<database>), and uses the same
+serial number counter as all other certificates sign with the
+self-signed certificate.
+
+=item B<-passin arg>
+
+The key password source. For more information about the format of B<arg>
+see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
+
+=item B<-notext>
+
+Don't output the text form of a certificate to the output file.
+
+=item B<-startdate date>
+
+This allows the start date to be explicitly set. The format of the
+date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure), or
+YYYYMMDDHHMMSSZ (the same as an ASN1 GeneralizedTime structure). In
+both formats, seconds SS and timezone Z must be present.
+
+=item B<-enddate date>
+
+This allows the expiry date to be explicitly set. The format of the
+date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure), or
+YYYYMMDDHHMMSSZ (the same as an ASN1 GeneralizedTime structure). In
+both formats, seconds SS and timezone Z must be present.
+
+=item B<-days arg>
+
+The number of days to certify the certificate for.
+
+=item B<-md alg>
+
+The message digest to use.
+Any digest supported by the OpenSSL B<dgst> command can be used. For signing
+algorithms that do not support a digest (i.e. Ed25519 and Ed448) any message
+digest that is set is ignored. This option also applies to CRLs.
+
+=item B<-policy arg>
+
+This option defines the CA "policy" to use. This is a section in
+the configuration file which decides which fields should be mandatory
+or match the CA certificate. Check out the B<POLICY FORMAT> section
+for more information.
+
+=item B<-msie_hack>
+
+This is a deprecated option to make B<ca> work with very old versions of
+the IE certificate enrollment control "certenr3". It used UniversalStrings
+for almost everything. Since the old control has various security bugs
+its use is strongly discouraged.
+
+=item B<-preserveDN>
+
+Normally the DN order of a certificate is the same as the order of the
+fields in the relevant policy section. When this option is set the order
+is the same as the request. This is largely for compatibility with the
+older IE enrollment control which would only accept certificates if their
+DNs match the order of the request. This is not needed for Xenroll.
+
+=item B<-noemailDN>
+
+The DN of a certificate can contain the EMAIL field if present in the
+request DN, however it is good policy just having the e-mail set into
+the altName extension of the certificate. When this option is set the
+EMAIL field is removed from the certificate' subject and set only in
+the, eventually present, extensions. The B<email_in_dn> keyword can be
+used in the configuration file to enable this behaviour.
+
+=item B<-batch>
+
+This sets the batch mode. In this mode no questions will be asked
+and all certificates will be certified automatically.
+
+=item B<-extensions section>
+
+The section of the configuration file containing certificate extensions
+to be added when a certificate is issued (defaults to B<x509_extensions>
+unless the B<-extfile> option is used). If no extension section is
+present then, a V1 certificate is created. If the extension section
+is present (even if it is empty), then a V3 certificate is created. See the:w
+L<x509v3_config(5)> manual page for details of the
+extension section format.
+
+=item B<-extfile file>
+
+An additional configuration file to read certificate extensions from
+(using the default section unless the B<-extensions> option is also
+used).
+
+=item B<-engine id>
+
+Specifying an engine (by its unique B<id> string) will cause B<ca>
+to attempt to obtain a functional reference to the specified engine,
+thus initialising it if needed. The engine will then be set as the default
+for all available algorithms.
+
+=item B<-subj arg>
+
+Supersedes subject name given in the request.
+The arg must be formatted as I</type0=value0/type1=value1/type2=...>,
+characters may be escaped by \ (backslash), no spaces are skipped.
+
+=item B<-utf8>
+
+This option causes field values to be interpreted as UTF8 strings, by
+default they are interpreted as ASCII. This means that the field
+values, whether prompted from a terminal or obtained from a
+configuration file, must be valid UTF8 strings.
+
+=item B<-create_serial>
+
+If reading serial from the text file as specified in the configuration
+fails, specifying this option creates a new random serial to be used as next
+serial number.
+To get random serial numbers, use the B<-rand_serial> flag instead; this
+should only be used for simple error-recovery.
+
+=item B<-rand_serial>
+
+Generate a large random number to use as the serial number.
+This overrides any option or configuration to use a serial number file.
+
+=item B<-multivalue-rdn>
+
+This option causes the -subj argument to be interpreted with full
+support for multivalued RDNs. Example:
+
+I</DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe>
+
+If -multi-rdn is not used then the UID value is I<123456+CN=John Doe>.
+
+=item B<-rand file...>
+
+A file or files containing random data used to seed the random number
+generator.
+Multiple files can be specified separated by an OS-dependent character.
+The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
+all others.
+
+=item [B<-writerand file>]
+
+Writes random data to the specified I<file> upon exit.
+This can be used with a subsequent B<-rand> flag.
+
+=back
+
+=head1 CRL OPTIONS
+
+=over 4
+
+=item B<-gencrl>
+
+This option generates a CRL based on information in the index file.
+
+=item B<-crldays num>
+
+The number of days before the next CRL is due. That is the days from
+now to place in the CRL nextUpdate field.
+
+=item B<-crlhours num>
+
+The number of hours before the next CRL is due.
+
+=item B<-revoke filename>
+
+A filename containing a certificate to revoke.
+
+=item B<-valid filename>
+
+A filename containing a certificate to add a Valid certificate entry.
+
+=item B<-status serial>
+
+Displays the revocation status of the certificate with the specified
+serial number and exits.
+
+=item B<-updatedb>
+
+Updates the database index to purge expired certificates.
+
+=item B<-crl_reason reason>
+
+Revocation reason, where B<reason> is one of: B<unspecified>, B<keyCompromise>,
+B<CACompromise>, B<affiliationChanged>, B<superseded>, B<cessationOfOperation>,
+B<certificateHold> or B<removeFromCRL>. The matching of B<reason> is case
+insensitive. Setting any revocation reason will make the CRL v2.
+
+In practice B<removeFromCRL> is not particularly useful because it is only used
+in delta CRLs which are not currently implemented.
+
+=item B<-crl_hold instruction>
+
+This sets the CRL revocation reason code to B<certificateHold> and the hold
+instruction to B<instruction> which must be an OID. Although any OID can be
+used only B<holdInstructionNone> (the use of which is discouraged by RFC2459)
+B<holdInstructionCallIssuer> or B<holdInstructionReject> will normally be used.
+
+=item B<-crl_compromise time>
+
+This sets the revocation reason to B<keyCompromise> and the compromise time to
+B<time>. B<time> should be in GeneralizedTime format that is B<YYYYMMDDHHMMSSZ>.
+
+=item B<-crl_CA_compromise time>
+
+This is the same as B<crl_compromise> except the revocation reason is set to
+B<CACompromise>.
+
+=item B<-crlexts section>
+
+The section of the configuration file containing CRL extensions to
+include. If no CRL extension section is present then a V1 CRL is
+created, if the CRL extension section is present (even if it is
+empty) then a V2 CRL is created. The CRL extensions specified are
+CRL extensions and B<not> CRL entry extensions. It should be noted
+that some software (for example Netscape) can't handle V2 CRLs. See
+L<x509v3_config(5)> manual page for details of the
+extension section format.
+
+=back
+
+=head1 CONFIGURATION FILE OPTIONS
+
+The section of the configuration file containing options for B<ca>
+is found as follows: If the B<-name> command line option is used,
+then it names the section to be used. Otherwise the section to
+be used must be named in the B<default_ca> option of the B<ca> section
+of the configuration file (or in the default section of the
+configuration file). Besides B<default_ca>, the following options are
+read directly from the B<ca> section:
+ RANDFILE
+ preserve
+ msie_hack
+With the exception of B<RANDFILE>, this is probably a bug and may
+change in future releases.
+
+Many of the configuration file options are identical to command line
+options. Where the option is present in the configuration file
+and the command line the command line value is used. Where an
+option is described as mandatory then it must be present in
+the configuration file or the command line equivalent (if
+any) used.
+
+=over 4
+
+=item B<oid_file>
+
+This specifies a file containing additional B<OBJECT IDENTIFIERS>.
+Each line of the file should consist of the numerical form of the
+object identifier followed by white space then the short name followed
+by white space and finally the long name.
+
+=item B<oid_section>
+
+This specifies a section in the configuration file containing extra
+object identifiers. Each line should consist of the short name of the
+object identifier followed by B<=> and the numerical form. The short
+and long names are the same when this option is used.
+
+=item B<new_certs_dir>
+
+The same as the B<-outdir> command line option. It specifies
+the directory where new certificates will be placed. Mandatory.
+
+=item B<certificate>
+
+The same as B<-cert>. It gives the file containing the CA
+certificate. Mandatory.
+
+=item B<private_key>
+
+Same as the B<-keyfile> option. The file containing the
+CA private key. Mandatory.
+
+=item B<RANDFILE>
+
+At startup the specified file is loaded into the random number generator,
+and at exit 256 bytes will be written to it.
+
+=item B<default_days>
+
+The same as the B<-days> option. The number of days to certify
+a certificate for.
+
+=item B<default_startdate>
+
+The same as the B<-startdate> option. The start date to certify
+a certificate for. If not set the current time is used.
+
+=item B<default_enddate>
+
+The same as the B<-enddate> option. Either this option or
+B<default_days> (or the command line equivalents) must be
+present.
+
+=item B<default_crl_hours default_crl_days>
+
+The same as the B<-crlhours> and the B<-crldays> options. These
+will only be used if neither command line option is present. At
+least one of these must be present to generate a CRL.
+
+=item B<default_md>
+
+The same as the B<-md> option. Mandatory except where the signing algorithm does
+not require a digest (i.e. Ed25519 and Ed448).
+
+=item B<database>
+
+The text database file to use. Mandatory. This file must be present
+though initially it will be empty.
+
+=item B<unique_subject>
+
+If the value B<yes> is given, the valid certificate entries in the
+database must have unique subjects. if the value B<no> is given,
+several valid certificate entries may have the exact same subject.
+The default value is B<yes>, to be compatible with older (pre 0.9.8)
+versions of OpenSSL. However, to make CA certificate roll-over easier,
+it's recommended to use the value B<no>, especially if combined with
+the B<-selfsign> command line option.
+
+Note that it is valid in some circumstances for certificates to be created
+without any subject. In the case where there are multiple certificates without
+subjects this does not count as a duplicate.
+
+=item B<serial>
+
+A text file containing the next serial number to use in hex. Mandatory.
+This file must be present and contain a valid serial number.
+
+=item B<crlnumber>
+
+A text file containing the next CRL number to use in hex. The crl number
+will be inserted in the CRLs only if this file exists. If this file is
+present, it must contain a valid CRL number.
+
+=item B<x509_extensions>
+
+The same as B<-extensions>.
+
+=item B<crl_extensions>
+
+The same as B<-crlexts>.
+
+=item B<preserve>
+
+The same as B<-preserveDN>
+
+=item B<email_in_dn>
+
+The same as B<-noemailDN>. If you want the EMAIL field to be removed
+from the DN of the certificate simply set this to 'no'. If not present
+the default is to allow for the EMAIL filed in the certificate's DN.
+
+=item B<msie_hack>
+
+The same as B<-msie_hack>
+
+=item B<policy>
+
+The same as B<-policy>. Mandatory. See the B<POLICY FORMAT> section
+for more information.
+
+=item B<name_opt>, B<cert_opt>
+
+These options allow the format used to display the certificate details
+when asking the user to confirm signing. All the options supported by
+the B<x509> utilities B<-nameopt> and B<-certopt> switches can be used
+here, except the B<no_signame> and B<no_sigdump> are permanently set
+and cannot be disabled (this is because the certificate signature cannot
+be displayed because the certificate has not been signed at this point).
+
+For convenience the values B<ca_default> are accepted by both to produce
+a reasonable output.
+
+If neither option is present the format used in earlier versions of
+OpenSSL is used. Use of the old format is B<strongly> discouraged because
+it only displays fields mentioned in the B<policy> section, mishandles
+multicharacter string types and does not display extensions.
+
+=item B<copy_extensions>
+
+Determines how extensions in certificate requests should be handled.
+If set to B<none> or this option is not present then extensions are
+ignored and not copied to the certificate. If set to B<copy> then any
+extensions present in the request that are not already present are copied
+to the certificate. If set to B<copyall> then all extensions in the
+request are copied to the certificate: if the extension is already present
+in the certificate it is deleted first. See the B<WARNINGS> section before
+using this option.
+
+The main use of this option is to allow a certificate request to supply
+values for certain extensions such as subjectAltName.
+
+=back
+
+=head1 POLICY FORMAT
+
+The policy section consists of a set of variables corresponding to
+certificate DN fields. If the value is "match" then the field value
+must match the same field in the CA certificate. If the value is
+"supplied" then it must be present. If the value is "optional" then
+it may be present. Any fields not mentioned in the policy section
+are silently deleted, unless the B<-preserveDN> option is set but
+this can be regarded more of a quirk than intended behaviour.
+
+=head1 SPKAC FORMAT
+
+The input to the B<-spkac> command line option is a Netscape
+signed public key and challenge. This will usually come from
+the B<KEYGEN> tag in an HTML form to create a new private key.
+It is however possible to create SPKACs using the B<spkac> utility.
+
+The file should contain the variable SPKAC set to the value of
+the SPKAC and also the required DN components as name value pairs.
+If you need to include the same component twice then it can be
+preceded by a number and a '.'.
+
+When processing SPKAC format, the output is DER if the B<-out>
+flag is used, but PEM format if sending to stdout or the B<-outdir>
+flag is used.
+
+=head1 EXAMPLES
+
+Note: these examples assume that the B<ca> directory structure is
+already set up and the relevant files already exist. This usually
+involves creating a CA certificate and private key with B<req>, a
+serial number file and an empty index file and placing them in
+the relevant directories.
+
+To use the sample configuration file below the directories demoCA,
+demoCA/private and demoCA/newcerts would be created. The CA
+certificate would be copied to demoCA/cacert.pem and its private
+key to demoCA/private/cakey.pem. A file demoCA/serial would be
+created containing for example "01" and the empty index file
+demoCA/index.txt.
+
+
+Sign a certificate request:
+
+ openssl ca -in req.pem -out newcert.pem
+
+Sign a certificate request, using CA extensions:
+
+ openssl ca -in req.pem -extensions v3_ca -out newcert.pem
+
+Generate a CRL
+
+ openssl ca -gencrl -out crl.pem
+
+Sign several requests:
+
+ openssl ca -infiles req1.pem req2.pem req3.pem
+
+Certify a Netscape SPKAC:
+
+ openssl ca -spkac spkac.txt
+
+A sample SPKAC file (the SPKAC line has been truncated for clarity):
+
+ SPKAC=MIG0MGAwXDANBgkqhkiG9w0BAQEFAANLADBIAkEAn7PDhCeV/xIxUg8V70YRxK2A5
+ CN=Steve Test
+ emailAddress=steve@openssl.org
+ 0.OU=OpenSSL Group
+ 1.OU=Another Group
+
+A sample configuration file with the relevant sections for B<ca>:
+
+ [ ca ]
+ default_ca = CA_default # The default ca section
+
+ [ CA_default ]
+
+ dir = ./demoCA # top dir
+ database = $dir/index.txt # index file.
+ new_certs_dir = $dir/newcerts # new certs dir
+
+ certificate = $dir/cacert.pem # The CA cert
+ serial = $dir/serial # serial no file
+ #rand_serial = yes # for random serial#'s
+ private_key = $dir/private/cakey.pem# CA private key
+ RANDFILE = $dir/private/.rand # random number file
+
+ default_days = 365 # how long to certify for
+ default_crl_days= 30 # how long before next CRL
+ default_md = md5 # md to use
+
+ policy = policy_any # default policy
+ email_in_dn = no # Don't add the email into cert DN
+
+ name_opt = ca_default # Subject name display option
+ cert_opt = ca_default # Certificate display option
+ copy_extensions = none # Don't copy extensions from request
+
+ [ policy_any ]
+ countryName = supplied
+ stateOrProvinceName = optional
+ organizationName = optional
+ organizationalUnitName = optional
+ commonName = supplied
+ emailAddress = optional
+
+=head1 FILES
+
+Note: the location of all files can change either by compile time options,
+configuration file entries, environment variables or command line options.
+The values below reflect the default values.
+
+ /usr/local/ssl/lib/openssl.cnf - master configuration file
+ ./demoCA - main CA directory
+ ./demoCA/cacert.pem - CA certificate
+ ./demoCA/private/cakey.pem - CA private key
+ ./demoCA/serial - CA serial number file
+ ./demoCA/serial.old - CA serial number backup file
+ ./demoCA/index.txt - CA text database file
+ ./demoCA/index.txt.old - CA text database backup file
+ ./demoCA/certs - certificate output file
+ ./demoCA/.rnd - CA random seed information
+
+=head1 RESTRICTIONS
+
+The text database index file is a critical part of the process and
+if corrupted it can be difficult to fix. It is theoretically possible
+to rebuild the index file from all the issued certificates and a current
+CRL: however there is no option to do this.
+
+V2 CRL features like delta CRLs are not currently supported.
+
+Although several requests can be input and handled at once it is only
+possible to include one SPKAC or self-signed certificate.
+
+=head1 BUGS
+
+The use of an in-memory text database can cause problems when large
+numbers of certificates are present because, as the name implies
+the database has to be kept in memory.
+
+The B<ca> command really needs rewriting or the required functionality
+exposed at either a command or interface level so a more friendly utility
+(perl script or GUI) can handle things properly. The script
+B<CA.pl> helps a little but not very much.
+
+Any fields in a request that are not present in a policy are silently
+deleted. This does not happen if the B<-preserveDN> option is used. To
+enforce the absence of the EMAIL field within the DN, as suggested by
+RFCs, regardless the contents of the request' subject the B<-noemailDN>
+option can be used. The behaviour should be more friendly and
+configurable.
+
+Canceling some commands by refusing to certify a certificate can
+create an empty file.
+
+=head1 WARNINGS
+
+The B<ca> command is quirky and at times downright unfriendly.
+
+The B<ca> utility was originally meant as an example of how to do things
+in a CA. It was not supposed to be used as a full blown CA itself:
+nevertheless some people are using it for this purpose.
+
+The B<ca> command is effectively a single user command: no locking is
+done on the various files and attempts to run more than one B<ca> command
+on the same database can have unpredictable results.
+
+The B<copy_extensions> option should be used with caution. If care is
+not taken then it can be a security risk. For example if a certificate
+request contains a basicConstraints extension with CA:TRUE and the
+B<copy_extensions> value is set to B<copyall> and the user does not spot
+this when the certificate is displayed then this will hand the requester
+a valid CA certificate.
+
+This situation can be avoided by setting B<copy_extensions> to B<copy>
+and including basicConstraints with CA:FALSE in the configuration file.
+Then if the request contains a basicConstraints extension it will be
+ignored.
+
+It is advisable to also include values for other extensions such
+as B<keyUsage> to prevent a request supplying its own values.
+
+Additional restrictions can be placed on the CA certificate itself.
+For example if the CA certificate has:
+
+ basicConstraints = CA:TRUE, pathlen:0
+
+then even if a certificate is issued with CA:TRUE it will not be valid.
+
+=head1 HISTORY
+
+Since OpenSSL 1.1.1, the program follows RFC5280. Specifically,
+certificate validity period (specified by any of B<-startdate>,
+B<-enddate> and B<-days>) will be encoded as UTCTime if the dates are
+earlier than year 2049 (included), and as GeneralizedTime if the dates
+are in year 2050 or later.
+
+=head1 SEE ALSO
+
+L<req(1)>, L<spkac(1)>, L<x509(1)>, L<CA.pl(1)>,
+L<config(5)>, L<x509v3_config(5)>
+
+=head1 COPYRIGHT
+
+Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.
+
+Licensed under the OpenSSL license (the "License"). You may not use
+this file except in compliance with the License. You can obtain a copy
+in the file LICENSE in the source distribution or at
+L<https://www.openssl.org/source/license.html>.
+
+=cut