如何测试X509TrustManager子类？

Question

I subclassed javax.net.ssl.X509TrustManager so I could use a private SSL cert. Now I am trying to write a JUnit test for my class, but the test cases keep giving me a null pointer exception.

Eg my implementation of checkClientTrusted() is an empty method. However, when I call that method with a (supposedly) valid instance of X509Certificate[] (and any sort of String for that matter), JUnit reports a NullException at that line of test code. Any suggestions as to what I am missing?

Answer 1

Subclassing 'X509TrustManager' just for the use of a self signed certificate (I assume thats what you mean with 'private SSL cert' ?) is a bit overkill. Easier ways to use such a certificate are:

Use a keystore file (truststore) with the certificate (or the certificate of the CA with which you created your self signed certificate) and point your application to that. All you have to do is make sure the 'SSLContext' knows about your truststore. Take a look at the (really well written) article Custom SSL for advanced JSSE developers for details. Technically this is even safer then using the global JRE truststore since only your certificate will be accepted as valid.

Add the certificate (or the certificate of the CA with which you created your self signed certificate) to the global truststore of the JRE with 'keytool'. The global JRE truststore is located in '$JAVA_HOME/lib/security/cacerts'. The password of the JRE truststore is always 'changeit'. Although this way obviously makes deployment harder, since sometimes you don't control the JRE installation.

Answer 2

The problem was I subclassed my test class from junit.framework.TestCase , which caused my @BeforeClass setup method not to get called (and therefore the variables I instantiated there were still null). After deleting that, things are working now.