[role="xpack"]
[[tls-http]]
==== Encrypting HTTP Client Communications

When {security} is enabled, you can optionally use TLS to ensure that
communication between HTTP clients and the cluster is encrypted.

NOTE: Enabling TLS on the HTTP layer is strongly recommended but is not required.
If you enable TLS on the HTTP layer in {es}, then you might need to make
configuration changes in other parts of the Elastic Stack and in any {es}
clients that you use.

. If you have not done so already, <<node-certificates,generate node certificates>>.

. Enable TLS and specify the information required to access the node’s
certificate.

** If the certificate is in PKCS#12 format, add the following information to the
`elasticsearch.yml` file on each node:
+
--
[source, yaml]
--------------------------------------------------
xpack.security.http.ssl.enabled: true
xpack.security.http.ssl.keystore.path: certs/elastic-certificates.p12 <1>
xpack.security.http.ssl.truststore.path: certs/elastic-certificates.p12 <2>
--------------------------------------------------
<1> If you created a separate certificate for each node, then you might need to
customize this path on each node. If the filename matches the node name, you can
use the `certs/${node.name}.p12` format, for example.
<2> The `elasticsearch-certutil` output includes the CA certificate inside the
PKCS#12 keystore, therefore the keystore can also be used as the truststore.
This name should match the `keystore.path` value.
--

** If the certificate is in PEM format, add the following information to the
`elasticsearch.yml` file on each node:
+
--
[source, yaml]
--------------------------------------------------
xpack.security.http.ssl.enabled: true
xpack.security.http.ssl.key:  /home/es/config/node01.key <1>
xpack.security.http.ssl.certificate: /home/es/config/node01.crt <2>
xpack.security.http.ssl.certificate_authorities: [ "/home/es/config/ca.crt" ] <3>
--------------------------------------------------
<1> The full path to the node key file. This must be a location within the
    {es} configuration directory.
<2> The full path to the node certificate. This must be a location within the
    {es} configuration directory.
<3> An array of paths to the CA certificates that should be trusted. These paths
    must be a location within the {es} configuration directory.
--

. If you secured the node's certificate with a password, add the password to
your {es} keystore:

** If the signed certificate is in PKCS#12 format, use the following commands:
+
--
[source,shell]
-----------------------------------------------------------
bin/elasticsearch-keystore add xpack.security.http.ssl.keystore.secure_password

bin/elasticsearch-keystore add xpack.security.http.ssl.truststore.secure_password
-----------------------------------------------------------
--

** If the certificate is in PEM format, use the following commands:
+
--
[source,shell]
-----------------------------------------------------------
bin/elasticsearch-keystore add xpack.security.http.ssl.secure_key_passphrase
-----------------------------------------------------------
--

. Restart {es}.

[NOTE]
===============================
* All TLS-related node settings are considered to be highly sensitive and
therefore are not exposed via the
{ref}/cluster-nodes-info.html#cluster-nodes-info[nodes info API] For more
information about any of these settings, see <<security-settings>>.

* {es} monitors all files such as certificates, keys, keystores, or truststores 
that are configured as values of TLS-related node settings. If you update any of 
these files (for example, when your hostnames change or your certificates are 
due to expire), {es} reloads them. The files are polled for changes at 
a frequency determined by the global {es} `resource.reload.interval.high` 
setting, which defaults to 5 seconds.
===============================
