Provided by: openssl_3.0.10-1ubuntu2.3_amd64 
NAME
openssl-ca - sample minimal CA application
SYNOPSIS
openssl ca [-help] [-verbose] [-config filename] [-name section] [-section section]
[-gencrl] [-revoke file] [-valid file] [-status serial] [-updatedb] [-crl_reason reason]
[-crl_hold instruction] [-crl_compromise time] [-crl_CA_compromise time] [-crl_lastupdate
date] [-crl_nextupdate date] [-crldays days] [-crlhours hours] [-crlsec seconds] [-crlexts
section] [-startdate date] [-enddate date] [-days arg] [-md arg] [-policy arg] [-keyfile
filename|uri] [-keyform DER|PEM|P12|ENGINE] [-key arg] [-passin arg] [-cert file]
[-certform DER|PEM|P12] [-selfsign] [-in file] [-inform DER|<PEM>] [-out file] [-notext]
[-dateopt] [-outdir dir] [-infiles] [-spkac file] [-ss_cert file] [-preserveDN]
[-noemailDN] [-batch] [-msie_hack] [-extensions section] [-extfile section] [-subj arg]
[-utf8] [-sigopt nm:v] [-vfyopt nm:v] [-create_serial] [-rand_serial] [-multivalue-rdn]
[-rand files] [-writerand file] [-engine id] [-provider name] [-provider-path path]
[-propquery propq] [certreq...]
DESCRIPTION
This command emulates a CA application. See the WARNINGS especially when considering to
use it productively. It can be used to sign certificate requests (CSRs) in a variety of
forms and generate certificate revocation lists (CRLs). It also maintains a text database
of issued certificates and their status. When signing certificates, a single request can
be specified with the -in option, or multiple requests can be processed by specifying a
set of certreq files after all options.
Note that there are also very lean ways of generating certificates: the req and x509
commands can be used for directly creating certificates. See openssl-req(1) and
openssl-x509(1) for details.
The descriptions of the ca command options are divided into each purpose.
OPTIONS
-help
Print out a usage message.
-verbose
This prints extra details about the operations being performed.
-config filename
Specifies the configuration file to use. Optional; for a description of the default
value, see "COMMAND SUMMARY" in openssl(1).
-name section, -section 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 (CSR) to be signed by the
CA.
-inform DER|PEM
The format of the data in certificate request input files; unspecified by default.
See openssl-format-options(1) for details.
-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 taken as 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 filename
The CA certificate, which must match with -keyfile.
-certform DER|PEM|P12
The format of the data in certificate input files; unspecified by default. See
openssl-format-options(1) for details.
-keyfile filename|uri
The CA private key to sign certificate requests with. This must match with -cert.
-keyform DER|PEM|P12|ENGINE
The format of the private key input file; unspecified by default. See
openssl-format-options(1) for details.
-sigopt nm:v
Pass options to the signature algorithm during sign operations. Names and values of
these options are algorithm-specific.
-vfyopt nm:v
Pass options to the signature algorithm during verify operations. Names and values of
these options are algorithm-specific.
This often needs to be given while signing too, because the self-signature of a
certificate signing request (CSR) is verified against the included public key, and
that verification may need its own set of options.
-key password
The password used to encrypt the private key. Since on some systems the command line
arguments are visible (e.g., when using ps(1) on Unix), this option should be used
with caution. Better use -passin.
-passin arg
The key password source for key files and certificate PKCS#12 files. For more
information about the format of arg see openssl-passphrase-options(1).
-selfsign
Indicates the issued certificates are to be signed with the key the certificate
requests were signed with (given with -keyfile). Certificate 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.
-notext
Don't output the text form of a certificate to the output file.
-dateopt
Specify the date output format. Values are: rfc_822 and iso_8601. Defaults to
rfc_822.
-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.
-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.
-days arg
The number of days to certify the certificate for.
-md alg
The message digest to use. Any digest supported by the openssl-dgst(1) 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.
-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 deprecated option to make this command 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.
-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 X.509 extensions are specified then a V1 certificate is created, else
a V3 certificate is created. See the 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).
-subj arg
Supersedes subject name given in the request.
The arg must be formatted as "/type0=value0/type1=value1/type2=...". Special
characters may be escaped by "\" (backslash), whitespace is retained. Empty values
are permitted, but the corresponding type will not be included in the resulting
certificate. Giving a single "/" will lead to an empty sequence of RDNs (a NULL-DN).
Multi-valued RDNs can be formed by placing a "+" character instead of a "/" between
the AttributeValueAssertions (AVAs) that specify the members of the set. Example:
"/DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe"
-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.
-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 -rand_serial flag instead; this should only be
used for simple error-recovery.
-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.
-multivalue-rdn
This option has been deprecated and has no effect.
-rand files, -writerand file
See "Random State Options" in openssl(1) for details.
-engine id
See "Engine Options" in openssl(1). This option is deprecated.
-provider name
-provider-path path
-propquery propq
See "Provider Options" in openssl(1), provider(7), and property(7).
CRL OPTIONS
-gencrl
This option generates a CRL based on information in the index file.
-crl_lastupdate time
Allows the value of the CRL's lastUpdate field to be explicitly set; if this option is
not present, the current time is used. Accepts times in YYMMDDHHMMSSZ format (the same
as an ASN1 UTCTime structure) or YYYYMMDDHHMMSSZ format (the same as an ASN1
GeneralizedTime structure).
-crl_nextupdate time
Allows the value of the CRL's nextUpdate field to be explicitly set; if this option is
present, any values given for -crldays, -crlhours and -crlsec are ignored. Accepts
times in the same formats as -crl_lastupdate.
-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.
-crlsec num
The number of seconds before the next CRL is due.
-revoke filename
A filename containing a certificate to revoke.
-valid filename
A filename containing a certificate to add a Valid certificate entry.
-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 practice 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 this command 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 whitespace
then the short name followed by whitespace 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
At startup the specified file is loaded into the random number generator, and at exit
256 bytes will be written to it. (Note: Using a RANDFILE is not necessary anymore, see
the "HISTORY" section.
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. Mandatory except where the signing algorithm does not
require a digest (i.e. Ed25519 and Ed448).
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.
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.
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
A fallback to the -extensions option.
crl_extensions
A fallback to the -crlexts option.
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 openssl-spkac(1).
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 directory structure this command assumes is already
set up and the relevant files already exist. This usually involves creating a CA
certificate and private key with openssl-req(1), 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 an SM2 certificate request:
openssl ca -in sm2.csr -out sm2.crt -md sm3 \
-sigopt "distid:1234567812345678" \
-vfyopt "distid:1234567812345678"
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 this command:
[ 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
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
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
This command is quirky and at times downright unfriendly.
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.
This command really needs rewriting or the required functionality exposed at either a
command or interface level so that a more user-friendly replacement could handle things
properly. The script 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 -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.
Canceling some commands by refusing to certify a certificate can create an empty file.
WARNINGS
This command was originally meant as an example of how to do things in a CA. Its code
does not have production quality. It was not supposed to be used as a full blown CA
itself, nevertheless some people are using it for this purpose at least internally. When
doing so, specific care should be taken to properly secure the private key(s) used for
signing certificates. It is advisable to keep them in a secure HW storage such as a smart
card or HSM and access them via a suitable engine or crypto provider.
This command command is effectively a single user command: no locking is done on the
various files and attempts to run more than one openssl 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 requester 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.
HISTORY
Since OpenSSL 1.1.1, the program follows RFC5280. Specifically, certificate validity
period (specified by any of -startdate, -enddate and -days) and CRL last/next update time
(specified by any of -crl_lastupdate, -crl_nextupdate, -crldays, -crlhours and -crlsec)
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.
OpenSSL 1.1.1 introduced a new random generator (CSPRNG) with an improved seeding
mechanism. The new seeding mechanism makes it unnecessary to define a RANDFILE for saving
and restoring randomness. This option is retained mainly for compatibility reasons.
The -section option was added in OpenSSL 3.0.0.
The -multivalue-rdn option has become obsolete in OpenSSL 3.0.0 and has no effect.
The -engine option was deprecated in OpenSSL 3.0.
SEE ALSO
openssl(1), openssl-req(1), openssl-spkac(1), openssl-x509(1), CA.pl(1), config(5),
x509v3_config(5)
COPYRIGHT
Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (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 <https://www.openssl.org/source/license.html>.