Call WS with Feign Client and Certificate

I am struggling with what seams basic but can not get my head around it. I hava a spring boot application which should expose a rest url.

I am doing it like:

@RestController
@RequestMapping(value = "/api")
public class MdmhController {

    @Resource
    private MdmhClient mdmhClient;


    @RequestMapping(
            method = RequestMethod.GET,
            value = "/myEntityNames",
            produces = { MediaType.APPLICATION_JSON_UTF8_VALUE }
    )
    ResponseEntity<Iterable<String>> getMyEntityNames() {

        MyEntity[] myEntities =
                mdmhClient.getMyentitis();

        Set<String> myEntityNames= new HashSet<>();
        for (MyEntity me : myEntities ) {
            myEntityNames.add(me.getName());
        }
        return new ResponseEntity<Iterable<String>>(myEntityNames, HttpStatus.OK);
    }
}

As you can see it consumes another service which I am trying to implement with a feign client:

@Import(FeignClientsConfiguration.class)
@Component
public class MdmhClientImpl implements MdmhClient {

    private final Decoder decoder;
    private final Encoder encoder;

    private  MdmhClient mdmhClient;

    @Value("${mdmh.serviceId}") // injected by sprins yaml e.g. url-to-service.com
    private String mdmhServiceId;

    @Autowired
    public MdmhClientImpl(
            final Decoder decoder, final Encoder encoder) {
        this.decoder = decoder;
        this.encoder = encoder;
    }

    @Override
    public MyEntity[] getMyEntities() {

        if (mdmhClient == null) {
            mdmhClient = Feign.builder()
                    .encoder(encoder)
                    .decoder(decoder)
                    .client(new Client.Default(TrustingSSLSocketFactory.get(), null))
                    .target(MdmhClient.class, "https://" + mdmhServiceId);
        }
        return mdmhClient.getMyEntity();
    }
}

The interface looks like:

@RestController
@RequestMapping(value = "/api")
public interface MdmhClient {

    @RequestLine("GET mdmh/service/v2/myentities")
    @Headers({ "accept: application/json" })
    MyEntity[] getMyEntities();
}

When MdmhClient does give me the exception at mdmhClient.getEntity() call:

SunCertPathBuilderException: unable to find valid certification path to requested target.

I know to solve this I need to import the certificate to the jre. I am running Intellij IDE and set the path of jdk of my project to:

C:\Program Files\Java\jdk1.8.0_65

I also accessed the webservice through firefox:

https://url-to-service.com/mdmh/service/v2/myentities

and downloaded the certificate which I imported to:

C:\Program Files\Java\jdk1.8.0_65\jre\lib\security\cacerts

But I do still get the error. Out of frustration I importet the certificate to all installed jdks, still same.

I found: https://github.com/OpenFeign/feign/blob/master/core/src/test/java/feign/client/TrustingSSLSocketFactory.java

and added it to my MdmhClient like:

@Override
public MyEntity[] getMyEntities() {

    if (mdmhClient == null) {
        Client client = new Client.Default(
                TrustingSSLSocketFactory.get(),
                new HostnameVerifier() {
                    @Override
                    public boolean verify(String s, SSLSession sslSession) {
                        return true;
                    }
                });
        mdmhClient = Feign.builder()
                .encoder(encoder)
                .decoder(decoder)
                .client(new Client.Default(TrustingSSLSocketFactory.get(), null))
                .target(MdmhClient.class, "https://" + mdmhServiceId);
    }
    return mdmhClient.getMyEntities();
}

after this I am getting an AccessDenied response from my called service.

ERROR [081-exec-3] 17.08.17 08:26:28.868  org.apache.juli.logging.DirectJDKLog@log: Servlet.service() for servlet [dispatcherServlet] in context with path [/lic] threw exception [Request processing failed; nested exception is feign.FeignException: status 403 reading MdmhClient#getFamilyVersions(); content:
<HTML><HEAD>
<TITLE>Access Denied</TITLE>
</HEAD>
<BODY>
<FONT f...

But I am 100% sure that I do not need authentication. As I can enter the URL to the browser without modifying headers and get a result.

I hope you can help me or give me some hints how to solve this.

Thank you

Solution

It looks like your client is accessing the service thru a proxy server. The proxy server requires authentication and thus responds with 403 and uses a different certificate (chain) and thus importing the certificate you got from the web service doesn't help.