Why can't I find the truststore for an SSL handshake?

Question

I'm using the Spring RESTTemplate on the client side to make calls to a REST endpoint. The client in this case is a Spring app and Tomcat is the servlet container.

I'm running into issues making a connection to an HTTPS endpoint. I am receiving an error which indicates it cannot find a valid path to the truststore. Where can I specify this? Is this done at the container level or the application config (Spring) level?

Stack trace:

org.springframework.web.client.ResourceAccessException: I/O error:
sun.security.validator.ValidatorException: PKIX path building failed:
sun.security.provider.certpath.SunCertPathBuilderException:
unable to find valid certification path to requested target;
nested exception is javax.net.ssl.SSLHandshakeException:
sun.security.validator.ValidatorException:
PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException:
unable to find valid certification path to requested target
org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:330)
org.springframework.web.client.RestTemplate.execute(RestTemplate.java:292)
org.springframework.web.client.RestTemplate.postForObject(RestTemplate.java:227)

Answer 1

More specifically, calling this method will do the trick, so that any subsequent HttpClient calls will not care about SSL certificate validity:

public static void trustSelfSignedSSL() {
    try {
        SSLContext ctx = SSLContext.getInstance("TLS");
        X509TrustManager tm = new X509TrustManager() {

            public void checkClientTrusted(X509Certificate[] xcs, String string) throws CertificateException {
            }

            public void checkServerTrusted(X509Certificate[] xcs, String string) throws CertificateException {
            }

            public X509Certificate[] getAcceptedIssuers() {
                return null;
            }
        };
        ctx.init(null, new TrustManager[]{tm}, null);
        SSLContext.setDefault(ctx);
    } catch (Exception ex) {
        ex.printStackTrace();
    }
}