<#import "/templates/guide.adoc" as tmpl>
<#import "/templates/kc.adoc" as kc>

<@tmpl.guide
title="Configuring trusted certificates"
summary="How to configure the {project_name} Truststore to communicate through TLS."
includedOptions="truststore-paths tls-hostname-verifier">

When {project_name} communicates with external services or has an incoming connection through TLS, it has to validate the remote certificate in order to ensure it is connecting to a trusted server. This is necessary in order to prevent man-in-the-middle attacks.

The certificates of these clients or servers, or the CA that signed these certificates, must be put in a truststore. This truststore is then configured for use by Keycloak.

== Configuring the System Truststore

The existing Java default truststore certs will always be trusted.  If you need additional certificates, which will be the case if you have self-signed or internal certificate authorities that are not recognized by the JRE, they can be included in the `conf/truststores` directory or subdirectories.  The certs may be in PEM files, or PKCS12 files with extension `.p12` or `.pfx`.  If in PKCS12, the certs must be unencrypted - meaning no password is expected.

If you need an alternative path, use the `--truststore-paths` option to specify additional files or directories where PEM or PKCS12 files are located. Paths are relative to where you launched {project_name}, so absolute paths are recommended instead. If a directory is specified, it will be recursively scanned for truststore files.

After all applicable certs are included, the truststore will be used as the system default truststore via the `javax.net.ssl` properties, and as the default for internal usage within {project_name}.  

For example:

<@kc.start parameters="--truststore-paths=/opt/truststore/myTrustStore.pfx,/opt/other-truststore/myOtherTrustStore.pem" />

It is still possible to directly set your own `javax.net.ssl` truststore System properties, but it's recommended to use the `--truststore-paths` instead.

== Hostname Verification Policy

You may refine how hostnames are verified by TLS connections with the `tls-hostname-verifier` property.

* `WILDCARD` (the default) allows wildcards in subdomain names, such as *.foo.com.
* `ANY` means that the hostname is not verified.
* When using `STRICT`, the Common Name (CN) must match the hostname exactly.
+
Please note that this setting does not apply to LDAP secure connections, which require strict hostname checking.

</@tmpl.guide>
