(Java) HMRC Validate Fraud Prevention Headers

Demonstrates how to test (validate) HMRC fraud prevention headers.

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import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkRest rest = new CkRest();

    boolean success = rest.Connect("test-api.service.hmrc.gov.uk",443,true,true);
    if (success == false) {
        System.out.println(rest.lastErrorText());
        return;
        }

    // Load the previously fetched access token.
    CkJsonObject json = new CkJsonObject();
    success = json.LoadFile("qa_data/tokens/hmrc.json");
    String accessToken = json.stringOf("access_token");
    System.out.println("Using access toke: " + accessToken);

    CkStringBuilder sbAuthHeaderValue = new CkStringBuilder();
    sbAuthHeaderValue.Append("Bearer ");
    sbAuthHeaderValue.Append(accessToken);

    rest.AddHeader("Accept","application/vnd.hmrc.1.0+json");
    rest.AddHeader("Authorization",sbAuthHeaderValue.getAsString());

    // Add the fraud prevention headers.
    // See https://developer.service.hmrc.gov.uk/api-documentation/docs/fraud-prevention
    rest.AddHeader("gov-client-connection-method","DESKTOP_APP_DIRECT");

    // This should be generated by an application and persistently stored on the device. The identifier should not expire.
    rest.AddHeader("gov-client-device-id","beec798b-b366-47fa-b1f8-92cede14a1ce");

    // See https://developer.service.hmrc.gov.uk/api-documentation/docs/fraud-prevention
    rest.AddHeader("gov-client-user-ids","os=user123");

    // Your local IP addresses (comma separated), such as addresses beginning with "192.168." or "172.16."
    rest.AddHeader("gov-client-local-ips","172.16.16.23");
    // You'll need to find a way to get your MAC address.  Chilkat does not yet provide this ability...
    rest.AddHeader("gov-client-mac-addresses","7C%3AD3%3A0A%3A25%3ADA%3A1C");

    rest.AddHeader("gov-client-timezone","UTC+00:00");

    // You can probably just hard-code these so they're always the same with each request.
    rest.AddHeader("gov-client-window-size","width=1256&height=800");
    rest.AddHeader("gov-client-screens","width=1920&height=1080&scaling-factor=1&colour-depth=16");
    rest.AddHeader("gov-client-user-agent","Windows/Server%202012 (Dell%20Inc./OptiPlex%20980)");
    rest.AddHeader("gov-vendor-version","My%20Desktop%20Software=1.2.3.build4286");

    String responseStr = rest.fullRequestNoBody("GET","/test/fraud-prevention-headers/validate");
    if (rest.get_LastMethodSuccess() == false) {
        System.out.println(rest.lastErrorText());
        return;
        }

    // If the status code is 200, then the fraud prevention headers were validated.
    // The JSON response may include some warnings..
    System.out.println("Response status code = " + rest.get_ResponseStatusCode());
    System.out.println("Response JSON body: ");
    System.out.println(responseStr);
  }
}