Thank you for your advice. I ended up also looking at https://stackoverflow.com/questions/16747902/setting-trust-store-programatically-in-activemqsslconnectionfactory-seems-to-fai and also https://github.com/apache/activemq/blob/master/activemq-amqp/src/test/java/org/apache/activemq/transport/amqp/joram/JoramJmsNioPlusSslTest.java and I did it the way the test in the second link does it.
try { SSLContext def; SSLContext ctx = SSLContext.getInstance("TLS"); ctx.init(new KeyManager[0], new TrustManager[]{new TrustingTrustManager()}, null); def = SSLContext.getDefault(); SSLContext.setDefault(ctx); } catch (NoSuchAlgorithmException | KeyManagementException e) { throw new RuntimeException("Could not set up the all-trusting TrustManager", e); } /** * Does not do any checking. Trusts all certificates. */ private class TrustingTrustManager implements X509TrustManager { @Override public void checkClientTrusted(X509Certificate[] x509Certificates, String s) throws CertificateException { } @Override public void checkServerTrusted(X509Certificate[] x509Certificates, String s) throws CertificateException { } @Override public X509Certificate[] getAcceptedIssuers() { return new X509Certificate[0]; } } Thank you all for your help. -- Jiri Daněk