elasticsearch-certutil

The elasticsearch-certutil command simplifies the creation of certificates for use with Transport Layer Security (TLS) in the Elastic Stack.

bin/elasticsearch-certutil
(
(ca [--ca-dn <name>] [--days <n>] [--pem])

| (cert ([--ca <file_path>] | [--ca-cert <file_path> --ca-key <file_path>])
[--ca-dn <name>] [--ca-pass <password>] [--days <n>]
[--dns <domain_name>] [--in <input_file>] [--ip <ip_addresses>]
[--multiple] [--name <file_name>] [--pem] [--self-signed])

| (csr [--dns <domain_name>] [--in <input_file>] [--ip <ip_addresses>]
[--name <file_name>])

[-E <KeyValuePair>] [--keysize <bits>] [--out <file_path>]
[--pass <password>]
)

| http

[-h, --help] ([-s, --silent] | [-v, --verbose])

You can specify one of the following modes: ca, cert, csr, http. The elasticsearch-certutil command also supports a silent mode of operation to enable easier batch operations.

The ca mode generates a new certificate authority (CA). By default, it produces a single PKCS#12 output file, which holds the CA certificate and the private key for the CA. If you specify the --pem parameter, the command generates a zip file, which contains the certificate and private key in PEM format.

You can subsequently use these files as input for the cert mode of the command.

The cert mode generates X.509 certificates and private keys. By default, it produces a single certificate and key for use on a single instance.

To generate certificates and keys for multiple instances, specify the --multiple parameter, which prompts you for details about each instance. Alternatively, you can use the --in parameter to specify a YAML file that contains details about the instances.

An instance is any piece of the Elastic Stack that requires a TLS or SSL certificate. Depending on your configuration, Elasticsearch, Logstash, Kibana, and Beats might all require a certificate and private key. The minimum required information for an instance is its name, which is used as the common name for the certificate. The instance name can be a hostname value or a full distinguished name. If the instance name would result in an invalid file or directory name, you must also specify a file name in the --name command parameter or in the filename field in an input YAML file.

You can optionally provide IP addresses or DNS names for each instance. If neither IP addresses nor DNS names are specified, the Elastic Stack products cannot perform hostname verification and you might need to configure the verification_mode security setting to certificate only. For more information about this setting, see Security settings.

All certificates that are generated by this command are signed by a CA unless the --self-signed parameter is specified. You must provide your own CA with the --ca or --ca-cert and --ca-key parameters unless --self-signed is specified. For more information about generating a CA, see the CA mode of this command. To generate self-signed certificates, use the --self-signed parameter.

By default, the cert mode produces a single PKCS#12 output file which holds the instance certificate, the instance private key, and the CA certificate. If you specify the --pem parameter, the command generates PEM formatted certificates and keys and packages them into a zip file. If you specify the --multiple or --in parameters, the command produces a zip file containing the generated certificates and keys.

The csr mode generates certificate signing requests (CSRs) that you can send to a trusted certificate authority to obtain signed certificates. The signed certificates must be in PEM or PKCS#12 format to work with Elasticsearch security features.

By default, the command produces a single CSR for a single instance.

To generate CSRs for multiple instances, specify the --multiple parameter, which prompts you for details about each instance. Alternatively, you can use the --in parameter to specify a YAML file that contains details about the instances.

The csr mode produces a single zip file which contains the CSRs and the private keys for each instance. Each CSR is provided as a standard PEM encoding of a PKCS#10 CSR. Each key is provided as a PEM encoding of an RSA private key.

The http mode guides you through the process of generating certificates for use on the HTTP (REST) interface for Elasticsearch. It asks you a number of questions in order to generate the right set of files for your needs. For example, depending on your choices, it might generate a zip file that contains a certificate authority (CA), a certificate signing request (CSR), or certificates and keys for use in Elasticsearch and Kibana. Each folder in the zip file contains a readme that explains how to use the files.

ca

Specifies to generate a new local certificate authority (CA). This parameter cannot be used with the csr, cert or http parameters.

cert

Specifies to generate new X.509 certificates and keys. This parameter cannot be used with the csr, ca or http parameters.

csr

Specifies to generate certificate signing requests. This parameter cannot be used with the ca, cert or http parameters.

http

Generates a new certificate or certificate request for the Elasticsearch HTTP interface. This parameter cannot be used with the ca, cert or csr parameters.

--ca <file_path>

Specifies the path to an existing CA key pair (in PKCS#12 format). This parameter is only applicable to the cert parameter.

--ca-cert <file_path>

Specifies the path to an existing CA certificate (in PEM format). You must also specify the --ca-key parameter. The --ca-cert parameter is only applicable to the cert parameter.

--ca-dn <name>

Defines the Distinguished Name (DN) that is used for the generated CA certificate. The default value is CN=Elastic Certificate Tool Autogenerated CA. This parameter cannot be used with the csr or http parameters.

--ca-key <file_path>

Specifies the path to an existing CA private key (in PEM format). You must also specify the --ca-cert parameter. The --ca-key parameter is only applicable to the cert parameter.

--ca-pass <password>

Specifies the password for an existing CA private key or the generated CA private key. This parameter is only applicable to the cert parameter

--days <n>

Specifies an integer value that represents the number of days the generated certificates are valid. The default value is 1095. This parameter cannot be used with the csr or http parameters.

--dns <domain_name>

Specifies a comma-separated list of DNS names. This parameter cannot be used with the ca or http parameters.

-E <KeyValuePair>

Configures a setting.

-h, --help

Returns all of the command parameters.

--in <input_file>

Specifies the file that is used to run in silent mode. The input file must be a YAML file. This parameter cannot be used with the ca or http parameters.

--ip <IP_addresses>

Specifies a comma-separated list of IP addresses. This parameter cannot be used with the ca or http parameters.

--keysize <bits>

Defines the number of bits that are used in generated RSA keys. The default value is 2048. This parameter cannot be used with the http parameter.

--multiple

Specifies to generate files for multiple instances. This parameter cannot be used with the ca or http parameters.

--name <file_name>

Specifies the name of the generated certificate. This parameter cannot be used with the ca or http parameters.

--out <file_path>

Specifies a path for the output files. This parameter cannot be used with the http parameter.

--pass <password>

Specifies the password for the generated private keys. This parameter cannot be used with the http parameters.

Keys stored in PKCS#12 format are always password protected, however, this password may be blank. If you want to specify a blank password without a prompt, use --pass "" (with no =) on the command line.

Keys stored in PEM format are password protected only if the --pass parameter is specified. If you do not supply an argument for the --pass parameter, you are prompted for a password. Encrypted PEM files do not support blank passwords (if you do not wish to password-protect your PEM keys, then do not specify --pass).

--pem

Generates certificates and keys in PEM format instead of PKCS#12. This parameter cannot be used with the csr or http parameters.

--self-signed

Generates self-signed certificates. This parameter is only applicable to the cert parameter.

Note

This option is not recommended for setting up TLS on a cluster. In fact, a self-signed certificate should be used only when you can be sure that a CA is definitely not needed and trust is directly given to the certificate itself.

-s, --silent

Shows minimal output.

-v, --verbose

Shows verbose output.

The following command generates a CA certificate and private key in PKCS#12 format:

bin/elasticsearch-certutil ca

You are prompted for an output filename and a password. Alternatively, you can specify the --out and --pass parameters.

You can then generate X.509 certificates and private keys by using the new CA. For example:

bin/elasticsearch-certutil cert --ca elastic-stack-ca.p12

You are prompted for the CA password and for an output filename and password. Alternatively, you can specify the --ca-pass, --out, and --pass parameters.

By default, this command generates a file called elastic-certificates.p12, which you can copy to the relevant configuration directory for each Elastic product that you want to configure. For more information, see Encrypt internode communications with TLS.

To use the silent mode of operation, you must create a YAML file that contains information about the instances. It must match the following format:

instances:
  - name: "node1" 1
    ip: 2
      - "192.0.2.1"
    dns: 3
      - "node1.mydomain.com"
  - name: "node2"
    ip:
      - "192.0.2.2"
      - "198.51.100.1"
  - name: "node3"
  - name: "node4"
    dns:
      - "node4.mydomain.com"
      - "node4.internal"
  - name: "CN=node5,OU=IT,DC=mydomain,DC=com"
    filename: "node5" 4

1. The name of the instance. This can be a simple string value or can be a Distinguished Name (DN). This is the only required field.
2. An optional array of strings that represent IP Addresses for this instance. Both IPv4 and IPv6 values are allowed. The values are added as Subject Alternative Names.
3. An optional array of strings that represent DNS names for this instance. The values are added as Subject Alternative Names.
4. The filename to use for this instance. This name is used as the name of the directory that contains the instance’s files in the output. It is also used in the names of the files within the directory. This filename should not have an extension. Note: If the name provided for the instance does not represent a valid filename, then the filename field must be present.

When your YAML file is ready, you can use the elasticsearch-certutil command to generate certificates or certificate signing requests. Simply use the --in parameter to specify the location of the file. For example:

bin/elasticsearch-certutil cert --silent --in instances.yml --out test1.zip --pass testpassword --ca elastic-stack-ca.p12

This command generates a compressed test1.zip file. After you decompress the output file, there is a directory for each instance that was listed in the instances.yml file. Each instance directory contains a single PKCS#12 (.p12) file, which contains the instance certificate, instance private key, and CA certificate.

You can also use the YAML file to generate certificate signing requests. For example:

bin/elasticsearch-certutil csr --silent --in instances.yml --out test2.zip --pass testpassword

This command generates a compressed file, which contains a directory for each instance. Each instance directory contains a certificate signing request (*.csr file) and private key (*.key file).