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.

In order to use HTTPS, use the Java command line tool keytool. It is automatically shipped with each JRE installation. Find more details about the keytool in the official documentation.

Standalone HTTPS with Jetty

To configure Horizon to protect web sessions with HTTPS, see How to setup SSL with Jetty.

Horizon as HTTPS client

To establish secure HTTPS connections within Java one has to setup a so called Java Truststore.

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

Setup Java Truststore

To setup the Java Truststore the following command can be issued.

If you do not have a Java Truststore setup 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 to import a certificate or a certificate chain
2	Use verbose output
3	Define to trust certificates from cacerts
4	The alias for the certificate to import, e.g. the common name
5	The certificate to import
6	The location of the Java Truststore

If you create a new Java Truststore you are asked for a password to protect the Java Truststore. If you updated an existing Java Truststore please type the password you chose when you first created the Java Truststore.

Download existing public certificate

To Download an existing public certificate the following command can be issued.

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, e.g. localhost:443
4	This is optional, but 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 setup Horizon to use the defined Java Truststore the according javax.net.ssl.trustStore* properties have to be set. 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	The location of the Java Truststore
2	The password of the Java Truststore

For more details on the Java built-in SSL System properties have a look at chapter 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 is used to determine whether a remote connection should be trusted or not, e.g., whether a remote party is who it claims to be (client use case).

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

For more details, please check 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 build-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 containing an application process’s own certificate and private key.
`javax.net.ssl.keyStorePassword`	Password to access the private key from the keystore file specified by `javax.net.ssl.keyStore`. This password is used twice: to unlock the keystore file (store password) and to decrypt the private key stored in the keystore (key password). In other words, 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 containing the collection of CA certificates trusted by this application process (truststore). 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) specified by `javax.net.ssl.trustStore`.
`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. More details about possible values can be found here.