CA

NAME

SYNOPSIS

DESCRIPTION

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 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.

-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.

-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. 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.

-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 it's unique id string) will cause req 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.

-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.

CONFIGURATION FILE OPTIONS

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

SPKAC FORMAT

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 '.'.  

EXAMPLES

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

 /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

RESTRICTIONS

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 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 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

Index

NAME

SYNOPSIS

DESCRIPTION

CA OPTIONS

CRL OPTIONS

CONFIGURATION FILE OPTIONS

POLICY FORMAT

SPKAC FORMAT

EXAMPLES

FILES

ENVIRONMENT VARIABLES

RESTRICTIONS

BUGS

WARNINGS

SEE ALSO