Consuming Java / Spring rest service using HTTPs(and certificate)

Question

I have to consume a rest service which is running on HTTPs. The producer has given me the certificate and method arguments. Could you please let me know how to consume the service and how to use the certificate in code. I am using Spring 4, Java 8. Please share the code snippet.

You can use the Spring Rest Template. [This answer can help you](https://stackoverflow.com/questions/17619871/access-https-rest-service-using-spring-resttemplate) take a look at some code snippets over there and see if you get what you need. — andreybleme, Jul 22 '17 at 03:40

score 0 · Answer 1 · answered Jul 22 '17 at 04:30

If it is just an one way SSL where consumer validates the identity of the service, you simply need to import the certificate provided by the service(producers certificate) to you trust store (CACerts file) or write your own trust manager.

For 2 Way SSL where service also authenticate the client's identity, you not only need to validate the identity of the service, you also need to send your certificate to the service so that service can take decision on it.

Following snippet is for 2 way SSL, but you can easily adopt it to 1 way SSL by commenting out the portion which sends client certicate to the server.

    // Create a trust manager that does not validate certificate chains
    TrustManager[] trustAllCerts = new TrustManager[]{new X509TrustManager(){
        public X509Certificate[] getAcceptedIssuers(){return null;}
        public void checkClientTrusted(X509Certificate[] certs, String authType){}
        public void checkServerTrusted(X509Certificate[] certs, String authType){}
    }};

    // Install the all-trusting trust manager
    RestTemplate restTemplate = new RestTemplate();

    try {

        String keyPassphrase = "changeit";

        KeyStore keyStore = KeyStore.getInstance("jks");
        keyStore.load(new FileInputStream("c:\\jks\\client.jks"), keyPassphrase.toCharArray());

        KeyManagerFactory kmfactory = KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm());           
        kmfactory.init(keyStore, keyPassphrase.toCharArray());

        KeyManager[] keyManager = kmfactory.getKeyManagers();

        SSLContext sc = SSLContext.getInstance("TLS");

        sc.init(keyManager, trustAllCerts, new SecureRandom());

        HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());

        HttpsURLConnection.setDefaultHostnameVerifier(new javax.net.ssl.HostnameVerifier(){

            public boolean verify(String hostname,
                    javax.net.ssl.SSLSession sslSession) {
                if (hostname.equals("localhost")) {
                    return true;
                }
                return false;
            }
        });

    } catch (Exception e) {
        ;
    }       




    System.out.println("Testing listAllUsers API-----------");


    restTemplate.setErrorHandler(new ResponseErrorHandler(){

        @Override
        public void handleError(ClientHttpResponse rs) throws IOException {
            InputStream in = rs.getBody();
            String str = new String("");
            int len =0;
            while((len = in.available()) > 0){
                byte[] bytes = new byte[len];
                in.read(bytes);
               str = str + new String (bytes, "UTF-8");

            }

            System.out.println(str);

        }

        @Override
        public boolean hasError(ClientHttpResponse rs) throws IOException {

            return false;
        }

    });
    try{

    String usersMap = restTemplate.getForObject(REST_SERVICE_URI+"/user/shailendra/", String.class);`

Consuming Java / Spring rest service using HTTPs(and certificate)

1 Answers1