Yolinux.com

CA manpage

Search topic Section


CA(1)				    OpenSSL				 CA(1)



NAME
       ca - sample minimal CA application

SYNOPSIS
       openssl ca [-verbose] [-config filename] [-name section] [-gencrl]
       [-revoke file] [-status serial] [-updatedb] [-crl_reason reason]
       [-crl_hold instruction] [-crl_compromise time] [-crl_CA_compromise
       time] [-crldays days] [-crlhours hours] [-crlexts section] [-startdate
       date] [-enddate date] [-days arg] [-md arg] [-policy arg] [-keyfile
       arg] [-keyform PEM|DER] [-key arg] [-passin arg] [-cert file]
       [-selfsign] [-in file] [-out file] [-notext] [-outdir dir] [-infiles]
       [-spkac file] [-ss_cert file] [-preserveDN] [-noemailDN] [-batch]
       [-msie_hack] [-extensions section] [-extfile section] [-engine id]
       [-subj arg] [-utf8] [-multivalue-rdn]

DESCRIPTION
       The 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.

CA OPTIONS
       -config filename
	   specifies the configuration file to use.

       -name section
	   specifies the configuration file section to use (overrides
	   default_ca in the ca section).

       -in filename
	   an input filename containing a single certificate request to be
	   signed by the CA.

       -ss_cert filename
	   a single self signed certificate to be signed by the CA.

       -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 SPKAC
	   FORMAT section for information on the required input and output
	   format.

       -infiles
	   if present this should be the last option, all subsequent arguments
	   are assumed to the the names of files containing certificate
	   requests.

       -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 -spkac outputs DER format).

       -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.

       -cert
	   the CA certificate file.

       -keyfile filename
	   the private key to sign requests with.

       -keyform PEM|DER
	   the format of the data in the private key file.  The default is
	   PEM.

       -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.

       -selfsign
	   indicates the issued certificates are to be signed with the key the
	   certificate requests were signed with (given with -keyfile).
	   Cerificate requests signed with a different key are ignored.	 If
	   -spkac, -ss_cert or -gencrl are given, -selfsign is ignored.

	   A consequence of using -selfsign is that the self-signed
	   certificate appears among the entries in the certificate database
	   (see the configuration option database), and uses the same serial
	   number counter as all other certificates sign with the self-signed
	   certificate.

       -passin arg
	   the key password source. For more information about the format of
	   arg see the PASS PHRASE ARGUMENTS section in openssl(1).

       -verbose
	   this prints extra details about the operations being performed.

       -notext
	   don't output the text form of a certificate to the output file.

       -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).

       -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).

       -days arg
	   the number of days to certify the certificate for.

       -md alg
	   the message digest to use. Possible values include md5, sha1 and
	   mdc2.  For full list of digests see openssl dgst -h output. This
	   option also applies to CRLs.

       -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 POLICY FORMAT
	   section for more information.

       -msie_hack
	   this is a legacy option to make 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. The newer
	   control "Xenroll" does not need this option.

       -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.

       -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 email_in_dn
	   keyword can be used in the configuration file to enable this
	   behaviour.

       -batch
	   this sets the batch mode. In this mode no questions will be asked
	   and all certificates will be certified automatically.

       -extensions section
	   the section of the configuration file containing certificate
	   extensions to be added when a certificate is issued (defaults to
	   x509_extensions unless the -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 x509v3_config(5) manual page for
	   details of the extension section format.

       -extfile file
	   an additional configuration file to read certificate extensions
	   from (using the default section unless the -extensions option is
	   also used).

       -engine id
	   specifying an engine (by its unique id string) will cause 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.

       -subj arg
	   supersedes subject name given in the request.  The arg must be
	   formatted as /type0=value0/type1=value1/type2=..., characters may
	   be escaped by \ (backslash), no spaces are skipped.

       -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.

       -multivalue-rdn
	   this option causes the -subj argument to be interpretedt with full
	   support for multivalued RDNs. Example:

	   /DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe

	   If -multi-rdn is not used then the UID value is 123456+CN=John Doe.

CRL OPTIONS
       -gencrl
	   this option generates a CRL based on information in the index file.

       -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.

       -crlhours num
	   the number of hours before the next CRL is due.

       -revoke filename
	   a filename containing a certificate to revoke.

       -status serial
	   displays the revocation status of the certificate with the
	   specified serial number and exits.

       -updatedb
	   Updates the database index to purge expired certificates.

       -crl_reason reason
	   revocation reason, where reason is one of: unspecified,
	   keyCompromise, CACompromise, affiliationChanged, superseded,
	   cessationOfOperation, certificateHold or removeFromCRL. The
	   matching of reason is case insensitive. Setting any revocation
	   reason will make the CRL v2.

	   In practive removeFromCRL is not particularly useful because it is
	   only used in delta CRLs which are not currently implemented.

       -crl_hold instruction
	   This sets the CRL revocation reason code to certificateHold and the
	   hold instruction to instruction which must be an OID. Although any
	   OID can be used only holdInstructionNone (the use of which is
	   discouraged by RFC2459) holdInstructionCallIssuer or
	   holdInstructionReject will normally be used.

       -crl_compromise time
	   This sets the revocation reason to keyCompromise and the compromise
	   time to time. time should be in GeneralizedTime format that is
	   YYYYMMDDHHMMSSZ.

       -crl_CA_compromise time
	   This is the same as crl_compromise except the revocation reason is
	   set to CACompromise.

       -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 not CRL entry extensions.	 It should be noted
	   that some software (for example Netscape) can't handle V2 CRLs. See
	   x509v3_config(5) manual page for details of the extension section
	   format.

CONFIGURATION FILE OPTIONS
       The section of the configuration file containing options for ca is
       found as follows: If the -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 default_ca option of the ca section of the configuration
       file (or in the default section of the configuration file). Besides
       default_ca, the following options are read directly from the ca
       section:
	RANDFILE  preserve
	msie_hack With the exception of 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.

       oid_file
	   This specifies a file containing additional 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.

       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 = and the numerical form. The
	   short and long names are the same when this option is used.

       new_certs_dir
	   the same as the -outdir command line option. It specifies the
	   directory where new certificates will be placed. Mandatory.

       certificate
	   the same as -cert. It gives the file containing the CA certificate.
	   Mandatory.

       private_key
	   same as the -keyfile option. The file containing the CA private
	   key. Mandatory.

       RANDFILE
	   a file used to read and write random number seed information, or an
	   EGD socket (see RAND_egd(3)).

       default_days
	   the same as the -days option. The number of days to certify a
	   certificate for.

       default_startdate
	   the same as the -startdate option. The start date to certify a
	   certificate for. If not set the current time is used.

       default_enddate
	   the same as the -enddate option. Either this option or default_days
	   (or the command line equivalents) must be present.

       default_crl_hours default_crl_days
	   the same as the -crlhours and the -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.

       default_md
	   the same as the -md option. The message digest to use. Mandatory.

       database
	   the text database file to use. Mandatory. This file must be present
	   though initially it will be empty.

       unique_subject
	   if the value yes is given, the valid certificate entries in the
	   database must have unique subjects.	if the value no is given,
	   several valid certificate entries may have the exact same subject.
	   The default value is 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 no, especially if
	   combined with the -selfsign command line option.

       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.

       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.

       x509_extensions
	   the same as -extensions.

       crl_extensions
	   the same as -crlexts.

       preserve
	   the same as -preserveDN

       email_in_dn
	   the same as -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.

       msie_hack
	   the same as -msie_hack

       policy
	   the same as -policy. Mandatory. See the POLICY FORMAT section for
	   more information.

       name_opt, 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 x509 utilities -nameopt and -certopt switches can
	   be used here, except the no_signame and 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 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 strongly discouraged
	   because it only displays fields mentioned in the policy section,
	   mishandles multicharacter string types and does not display
	   extensions.

       copy_extensions
	   determines how extensions in certificate requests should be
	   handled.  If set to none or this option is not present then
	   extensions are ignored and not copied to the certificate. If set to
	   copy then any extensions present in the request that are not
	   already present are copied to the certificate. If set to 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 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.

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 -preserveDN option is set but this can be
       regarded more of a quirk than intended behaviour.

SPKAC FORMAT
       The input to the -spkac command line option is a Netscape signed public
       key and challenge. This will usually come from the KEYGEN tag in an
       HTML form to create a new private key.  It is however possible to
       create SPKACs using the 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 -out flag is
       used, but PEM format if sending to stdout or the -outdir flag is used.

EXAMPLES
       Note: these examples assume that the ca directory structure is already
       set up and the relevant files already exist. This usually involves
       creating a CA certificate and private key with 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 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
	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

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

ENVIRONMENT VARIABLES
       OPENSSL_CONF reflects the location of master configuration file it can
       be overridden by the -config command line option.

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.

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 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 scripts
       CA.sh and CA.pl help 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 -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 -noemailDN
       option can be used. The behaviour should be more friendly and
       configurable.

       Cancelling some commands by refusing to certify a certificate can
       create an empty file.

WARNINGS
       The ca command is quirky and at times downright unfriendly.

       The 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 ca command is effectively a single user command: no locking is done
       on the various files and attempts to run more than one ca command on
       the same database can have unpredictable results.

       The 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
       copy_extensions value is set to copyall and the user does not spot this
       when the certificate is displayed then this will hand the requestor a
       valid CA certificate.

       This situation can be avoided by setting copy_extensions to 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
       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.

SEE ALSO
       req(1), spkac(1), x509(1), CA.pl(1), config(5), x509v3_config(5)



1.0.2k				  2023-11-15				 CA(1)