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MAN page from RedHat EL 5 openssl10-1.0.2k-1.el5.pp.x86_64.rpm

CA

Section: OpenSSL (1)
Updated: 2017-01-26
Index 

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 usedto sign certificate requests in a variety of forms and generateCRLs it also maintains a text database of issued certificatesand 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 (overridesdefault_ca in the ca section).
-in filename
an input filename containing a single certificate request to besigned 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 challengeand additional field values to be signed by the CA. See the SPKAC FORMATsection for information on the required input and output format.
-infiles
if present this should be the last option, all subsequent argumentsare assumed to the the names of files containing certificate requests.
-out filename
the output file to output certificates to. The default is standardoutput. The certificate details will also be printed out to thisfile in PEM format (except that -spkac outputs DER format).
-outdir directory
the directory to output certificates to. The certificate will bewritten 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 somesystems the command line arguments are visible (e.g. Unix withthe 'ps' utility) this option should be used with caution.
-selfsign
indicates the issued certificates are to be signed with the keythe 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 isignored.

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

-passin arg
the key password source. For more information about the format of argsee 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 thedate is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure).
-enddate date
this allows the expiry date to be explicitly set. The format of thedate 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.This option also applies to CRLs.
-policy arg
this option defines the CA ``policy'' to use. This is a section inthe configuration file which decides which fields should be mandatoryor match the CA certificate. Check out the POLICY FORMAT sectionfor more information.
-msie_hack
this is a legacy option to make ca work with very old versions ofthe IE certificate enrollment control ``certenr3''. It used UniversalStringsfor almost everything. Since the old control has various security bugsits use is strongly discouraged. The newer control ``Xenroll'' does notneed this option.
-preserveDN
Normally the DN order of a certificate is the same as the order of thefields in the relevant policy section. When this option is set the order is the same as the request. This is largely for compatibility with theolder IE enrollment control which would only accept certificates if theirDNs 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 therequest DN, however it is good policy just having the e-mail set intothe altName extension of the certificate. When this option is set theEMAIL field is removed from the certificate' subject and set only inthe, eventually present, extensions. The email_in_dn keyword can beused in the configuration file to enable this behaviour.
-batch
this sets the batch mode. In this mode no questions will be askedand all certificates will be certified automatically.
-extensions section
the section of the configuration file containing certificate extensionsto be added when a certificate is issued (defaults to x509_extensionsunless the -extfile option is used). If no extension section ispresent then, a V1 certificate is created. If the extension sectionis present (even if it is empty), then a V3 certificate is created. See the:wx509v3_config(5) manual page for details of theextension section format.
-extfile file
an additional configuration file to read certificate extensions from(using the default section unless the -extensions option is alsoused).
-engine id
specifying an engine (by its unique id string) will cause cato attempt to obtain a functional reference to the specified engine,thus initialising it if needed. The engine will then be set as the defaultfor 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 fieldvalues, whether prompted from a terminal or obtained from aconfiguration file, must be valid UTF8 strings.
-multivalue-rdn
this option causes the -subj argument to be interpretedt with fullsupport 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 fromnow 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 specifiedserial 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 caseinsensitive. Setting any revocation reason will make the CRL v2.

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

-crl_hold instruction
This sets the CRL revocation reason code to certificateHold and the holdinstruction to instruction which must be an OID. Although any OID can beused 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 totime. 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 toCACompromise.
-crlexts section
the section of the configuration file containing CRL extensions toinclude. If no CRL extension section is present then a V1 CRL iscreated, if the CRL extension section is present (even if it isempty) then a V2 CRL is created. The CRL extensions specified areCRL extensions and not CRL entry extensions. It should be notedthat some software (for example Netscape) can't handle V2 CRLs. Seex509v3_config(5) manual page for details of theextension section format.
 

CONFIGURATION FILE OPTIONS

The section of the configuration file containing options for cais found as follows: If the -name command line option is used,then it names the section to be used. Otherwise the section tobe used must be named in the default_ca option of the ca sectionof the configuration file (or in the default section of theconfiguration file). Besides default_ca, the following options areread directly from the ca section:
 RANDFILE
 preserve
 msie_hackWith the exception of RANDFILE, this is probably a bug and maychange in future releases.

Many of the configuration file options are identical to command lineoptions. Where the option is present in the configuration fileand the command line the command line value is used. Where anoption is described as mandatory then it must be present inthe configuration file or the command line equivalent (ifany) used.

oid_file
This specifies a file containing additional OBJECT IDENTIFIERS.Each line of the file should consist of the numerical form of theobject identifier followed by white space then the short name followedby white space and finally the long name.
oid_section
This specifies a section in the configuration file containing extraobject identifiers. Each line should consist of the short name of theobject identifier followed by = and the numerical form. The shortand long names are the same when this option is used.
new_certs_dir
the same as the -outdir command line option. It specifiesthe directory where new certificates will be placed. Mandatory.
certificate
the same as -cert. It gives the file containing the CAcertificate. Mandatory.
private_key
same as the -keyfile option. The file containing theCA private key. Mandatory.
RANDFILE
a file used to read and write random number seed information, oran EGD socket (see RAND_egd(3)).
default_days
the same as the -days option. The number of days to certifya certificate for.
default_startdate
the same as the -startdate option. The start date to certifya certificate for. If not set the current time is used.
default_enddate
the same as the -enddate option. Either this option ordefault_days (or the command line equivalents) must bepresent.
default_crl_hours default_crl_days
the same as the -crlhours and the -crldays options. Thesewill only be used if neither command line option is present. Atleast 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 presentthough initially it will be empty.
unique_subject
if the value yes is given, the valid certificate entries in thedatabase 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 withthe -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 numberwill be inserted in the CRLs only if this file exists. If this file ispresent, 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 removedfrom the DN of the certificate simply set this to 'no'. If not presentthe 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 sectionfor more information.
name_opt, cert_opt
these options allow the format used to display the certificate detailswhen asking the user to confirm signing. All the options supported bythe x509 utilities -nameopt and -certopt switches can be usedhere, except the no_signame and no_sigdump are permanently setand cannot be disabled (this is because the certificate signature cannotbe displayed because the certificate has not been signed at this point).

For convenience the values ca_default are accepted by both to producea reasonable output.

If neither option is present the format used in earlier versions ofOpenSSL is used. Use of the old format is strongly discouraged becauseit only displays fields mentioned in the policy section, mishandlesmulticharacter 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 areignored and not copied to the certificate. If set to copy then anyextensions present in the request that are not already present are copiedto the certificate. If set to copyall then all extensions in therequest are copied to the certificate: if the extension is already presentin the certificate it is deleted first. See the WARNINGS section beforeusing this option.

The main use of this option is to allow a certificate request to supplyvalues for certain extensions such as subjectAltName.

 

POLICY FORMAT

The policy section consists of a set of variables corresponding tocertificate DN fields. If the value is ``match'' then the field valuemust match the same field in the CA certificate. If the value is``supplied'' then it must be present. If the value is ``optional'' thenit may be present. Any fields not mentioned in the policy sectionare silently deleted, unless the -preserveDN option is set butthis can be regarded more of a quirk than intended behaviour. 

SPKAC FORMAT

The input to the -spkac command line option is a Netscapesigned public key and challenge. This will usually come fromthe 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 ofthe SPKAC and also the required DN components as name value pairs.If you need to include the same component twice then it can bepreceded by a number and a '.'.

When processing SPKAC format, the output is DER if the -outflag is used, but PEM format if sending to stdout or the -outdirflag is used. 

EXAMPLES

Note: these examples assume that the ca directory structure isalready set up and the relevant files already exist. This usuallyinvolves creating a CA certificate and private key with req, aserial number file and an empty index file and placing them inthe relevant directories.

To use the sample configuration file below the directories demoCA,demoCA/private and demoCA/newcerts would be created. The CAcertificate would be copied to demoCA/cacert.pem and its privatekey to demoCA/private/cakey.pem. A file demoCA/serial would becreated containing for example ``01'' and the empty index filedemoCA/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=steveAATTopenssl.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 canbe 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 possibleto rebuild the index file from all the issued certificates and a currentCRL: 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 onlypossible to include one SPKAC or self signed certificate. 

BUGS

The use of an in memory text database can cause problems when largenumbers of certificates are present because, as the name impliesthe database has to be kept in memory.

The ca command really needs rewriting or the required functionalityexposed at either a command or interface level so a more friendly utility(perl script or GUI) can handle things properly. The scripts CA.sh andCA.pl help a little but not very much.

Any fields in a request that are not present in a policy are silentlydeleted. This does not happen if the -preserveDN option is used. Toenforce the absence of the EMAIL field within the DN, as suggested byRFCs, regardless the contents of the request' subject the -noemailDNoption can be used. The behaviour should be more friendly andconfigurable.

Cancelling some commands by refusing to certify a certificate cancreate 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 thingsin 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 isdone on the various files and attempts to run more than one ca commandon the same database can have unpredictable results.

The copy_extensions option should be used with caution. If care isnot taken then it can be a security risk. For example if a certificaterequest contains a basicConstraints extension with CA:TRUE and thecopy_extensions value is set to copyall and the user does not spotthis when the certificate is displayed then this will hand the requestora valid CA certificate.

This situation can be avoided by setting copy_extensions to copyand including basicConstraints with CA:FALSE in the configuration file.Then if the request contains a basicConstraints extension it will beignored.

It is advisable to also include values for other extensions suchas 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)


 

Index

NAME
SYNOPSIS
DESCRIPTION
CA OPTIONS
CRL OPTIONS
CONFIGURATION FILE OPTIONS
POLICY FORMAT
SPKAC FORMAT
EXAMPLES
FILES
ENVIRONMENT VARIABLES
RESTRICTIONS
BUGS
WARNINGS
SEE ALSO

This document was created byman2html,using the manual pages.