HTTPS/SSL

This section covers ways to configure Horizon to protect web sessions with HTTPS and also explains how to configure Horizon to establish secure connections.

To use HTTPS, use the Java command line tool keytool. It is automatically shipped with each JRE installation. To learn more about the keytool, see the official documentation.

Secure Horizon with HTTPS

To configure Horizon’s built-in Jetty process to protect web sessions with HTTPS, see How to set up SSL with Jetty. Alternatively, you can configure Apache or NGINX to act as a reverse proxy.

Horizon as HTTPS client

To establish secure HTTPS connections from Horizon to monitored nodes, you need to set up a Java Truststore.

The Java Truststore contains all certificates a Java application should trust when making connections as a client to a server.

Set up Java Truststore

Use the following command to set up the Java Truststore.

If you do not have a Java Truststore set up yet, it is created automatically.

Import a certificate to the Java Truststore

keytool \
  -import \ (1)
  -v \ (2)
  -trustcacerts \ (3)
  -alias localhost \ (4)
  -file localhost.cert \ (5)
  -keystore ${OPENNMS_HOME}/etc/trust-store.jks  (6)

1	Define certificate or a certificate chain import.
2	Use verbose output.
3	Trust certificates from `cacerts`.
4	The alias for the certificate to import; for example, the common name.
5	The certificate to import.
6	The location of the Java Truststore.

If you create a new Java Truststore, you must provide a password to protect the Java Truststore. If you updated an existing Java Truststore, type the password you chose when you first created the Java Truststore.

Download existing public certificate

Use the following command to download an existing public certificate.

Download an existing public certificate

openssl \
  s_client \ (1)
  -showcerts \ (2)
  -connect localhost:443 \ (3)
  -servername localhost \ (4)
  < /dev/null \ (5)
  > localhost.cert (6)

1	Use SSL/TLS client functionality of `openssl`.
2	Show all certificates in the chain.
3	PORT:HOST to connect to; for example, localhost:443.
4	Optional. If you are serving multiple certificates under one single IP address, you may define a server name; otherwise, the `ip of localhost`:PORT certificate is returned, which may not match the requested server name (`mail.domain.com`, `opennms.domain.com`, `dns.domain.com`).
5	No input
6	Where to store the certificate.

Configure Horizon to use the defined Java Truststore

To set up Horizon to use the defined Java Truststore, you must set the applicable javax.net.ssl.trustStore* properties. Open ${OPENNMS_HOME}/etc/opennms.properties and add the properties javax.net.ssl.trustStore and javax.net.ssl.trustStorePassword as shown below.

${OPENNMS_HOME}/etc/opennms.properties snippet to define a Java Truststore

javax.net.ssl.trustStore=${OPENNMS_HOME}/etc/trust-store.jks (1)
javax.net.ssl.trustStorePassword=change-me (2)

1	Java Truststore location
2	Java Truststore password

For more details on the Java built-in SSL system properties, see Debugging/Properties.

Each time you modify the Java Truststore you have to restart Horizon to have the changes take effect.

Differences between Java Truststore and Java Keystore

The Java Truststore determines whether a remote connection should be trusted or not; in other words, whether a remote party is who it claims to be (client use case).

The Java Keystore decides which authentication credentials should be sent to the remote host for authentication during SSL handshake (server use case).

For more details, see the JSSE Reference Guide.

Debugging/Properties

If you encounter issues while using HTTPS, it might be useful to enable debugging or use one of the built-in Java System Properties to configure the proper use of SSL.

Table 1. Java built-in System Properties (Source)
System Property Name	Description
javax.net.ssl.keyStore	Location of the Java keystore file that contains an application process’s own certificate and private key.
javax.net.ssl.keyStorePassword	Password to access the private key from the keystore file `javax.net.ssl.keyStore` specifies. This password is used twice: to unlock the keystore file (store password) and to decrypt the private key stored in the keystore (key password). The JSSE framework requires these passwords to be identical.
javax.net.ssl.keyStoreType	(Optional) For Java keystore file format, this property has the value `jks` (or `JKS`). You do not normally specify this property, because its default value is already `jks`.
javax.net.ssl.trustStore	Location of the Java keystore file that contains the collection of CA certificates this application process (truststore) trusts. If a truststore location is not specified using this property, the Sun JSSE implementation searches for and uses a keystore file in the following locations (in order): `${JAVA_HOME}/lib/security/jssecacerts` and `${JAVA_HOME}/lib/security/cacerts`.
javax.net.ssl.trustStorePassword	Password to unlock the keystore file (store password) javax.net.ssl.trustStore specifies.
javax.net.ssl.trustStoreType	(Optional) For Java keystore file format, this property has the value `jks` (or `JKS`). You do not normally specify this property, because its default value is already `jks`.
javax.net.debug	To switch on logging for the SSL/TLS layer, set this property to ssl. For more details about possible values, see debugging utilities.