Webtest with client authentication

Hi,

I came across the following problem, which is driving me crazy: 
I just want to test a web application, which uses a client authentication with certificates. I downloaded the doc.zip, which contains an example. The problem is, this example doesn't work. Not because of the missing web application, but the xml file contains invalid/missing declarations. It would be great to keep the doc up-to-date since - it is really frustrating if the sample doesn't work.

I am using canoo r_1810 with the following configuration for my test:

   <target name="test" depends="wt.defineMacros">

   <property name="webtest.keystore.file" value="certs/client.keystore" />
   <property name="webtest.keystore.passphrase" value="client" />
   <property name="webtest.truststore.file" value=".keystore"/>
   <property name="webtest.truststore.passphrase" value="test1234"/>
   <property name="webtest.connectioninitializer"  value="com.canoo.webtest.security.SunJsseBaseConnectionInitializer"/>    
   <property name="webtest.keystore.alias" value="user1" />
   
   <webtest name="Startseite aufrufen">
            <config 
                protocol="https"
                host="localhost"
                port="8443"
                useInsecureSSL="true">
            </config>
                    
            <invoke url="/index.html" description="Gehe zur Startseite"/>
            <verifyTitle text="TEST" />
....

There are two points I don't understand:

1. the truststore-file. What is it for? 
2. Whatever I type for the keystore-file, I always get the same error (from webserver): bad_certificate. And this bothers me, because I can't tell where the problem lies. Even if I tried a wrong password, the error message remains the same - it is always the same (even when no certificate is sent).

So, I am lost, because the error message I get doesn't help and the provided example doesn't show how I can convert a client certificate (a p12 file) into a keystore and why this is necessary.

I would be very helpful if someone tested a web application with a client authentication and can provide a working example. I really appreciate your help.

Thanks a lot in advance,
Daniel