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// Module is included in the following assemblies:
//
// securing-incoming-client-connections.adoc

[id='enabling-ssl-tls-client-authentication-{context}']
= Enabling SSL/TLS client authentication

In addition to SSL/TLS encryption, you can also use SSL/TLS to authenticate an incoming connection from a client. With this method, a clients must present its own X.509 certificate to the router, which the router uses to verify the client's identity.

.Prerequisites

* SSL/TLS encryption must be configured.
+
For more information, see xref:enabling-ssl-tls-encryption-{context}[].

* The client must have an X.509 certificate that it can use to authenticate to the router.

.Procedure

include::{FragmentDir}/fragment-router-open-config-file-step.adoc[]

. Configure the `listener` for this connection to use SSL/TLS to authenticate the client.
+
--
This example adds SSL/TLS authentication to a `normal` listener to authenticate incoming connections from a client. The client will only be able to connect to the router by presenting its own X.509 certificate to the router, which the router will use to verify the client's identity.

[options="nowrap",subs="+quotes"]
----
listener {
    host: 0.0.0.0
    port: 5672
    role: normal
    sslProfile: service-tls
    requireSsl: yes
    authenticatePeer: yes
    saslMechanisms: EXTERNAL
    ...
}
----
`authenticatePeer`:: Specify `yes` to authenticate the client's identity.

`saslMechanisms`:: Specify `EXTERNAL` to enable X.509 client certificate authentication.
--