Best practice for deploying spring boot application on Amazon - spring-mvc

Question

I've devloped a chat bot application using the Facebook Messenger platform.
I used Spring Boot with embedded Tomcat for the web platform.
The application should run on Amazon aws, open to the WWW, and to be used as a webhook for recieving callbacks from Messenger over https.
I need an advice how to secure the application, so it won't be hacked or flooded with requests that are not coming from Facebook.
I thought to make the application require secured (ssl) connection, but using the "security.require_ssl=true" in application.properties didn't do the work. Perhaps I don't know what is the meaning of this and how to configure it propertly.
Is there a best practice how to block requests which are not https requests? Or a way to block requests which are coming outside Messenger in the application level?
Thank you very much!
EDIT
In the meantime, I blocked requests from other IPs in application layer using the handler interceptor:
#Configuration
public class MyWebApplicationInitializer implements WebApplicationInitializer, WebMvcConfigurer{
#Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(new HandlerInterceptor() {
#Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
throws Exception {
if (! (request.getRemoteAddr().equals("173.252.88.66") || request.getRemoteAddr().equals("127.0.0.1")|| request.getRemoteAddr().equals("0:0:0:0:0:0:0:1"))){
logger.warn("Request is not coming from authorized remote address: " + request.getRemoteAddr()+". Rejecting");
response.getWriter().write("Unauthorized Address");
response.setStatus(401);
return false;
} else {
return true;
}
}
}

Answer 1

You should check the X-Hub-signature HTTP header available in the requests sent by Facebook to your webhook URL.
In your case, you may define a filter or interceptor for the verification of the signature. You can also do it in your controller as in the this example I found in RealTimeUpdateController.java from the spring social project.
private boolean verifySignature(String payload, String signature) throws Exception {
if (!signature.startsWith("sha1=")) {
return false;
}
String expected = signature.substring(5);
Mac mac = Mac.getInstance(HMAC_SHA1_ALGORITHM);
SecretKeySpec signingKey = new SecretKeySpec(applicationSecret.getBytes(), HMAC_SHA1_ALGORITHM);
mac.init(signingKey);
byte[] rawHmac = mac.doFinal(payload.getBytes());
String actual = new String(Hex.encode(rawHmac));
return expected.equals(actual);
}

Answer 2

a lot to say so I am sure I will miss some points.
setting SSL is a first good thing but make sure you get a certificate. lets encrypt is a good thing if you dont want to pay for SSL certificate.
Just seeing aws provides an alternative to letsencrypt
Security Group You can see Security Group as something similar to a firewall so you can control which port is opened, external and internal flows.
Look at IAM which control who and how can get access to your AWS account
obvious : change your password. do not let default password for installation you could make on the instance
read some of https://aws.amazon.com/security/security-resources/ to get more information about what you can do
it won't be hacked or flooded with requests
sorry to say but most probably it will be - It does not need to be an advanced hacker to run scanner and scan IPs and check open ports / brute force login etc ...

Answer 3

Thanks to Guy Bouallet help I added the signature check.
I added it in my controller and not in the interceptor, to avoid the problem of How to read data twice in spring which seems a little complicated.
So here is it:
#RequestMapping(path = "/")
public void doHandleCallback(#RequestBody String body, #RequestHeader(value = "X-Hub-Signature") String signature) throws IOException {
if (!verifyRequestSignature(body.getBytes(), signature)){
logger.error ("Signature mismatch.");
throw new MismatchSignatureException(signature);
}
MessengerCallback callback = mapper.readValue(body, MessengerCallback.class);
logger.info("Incoming Callback: " + body );
for (EventData entry : callback.getEntry()) {
for (ReceivedMessagingObject message : entry.getMessaging()) {
if (message.isMessage() || message.isPostback()) {
doHandleMessage(message);
}
else if (message.isDelivery()){
doHandleDelivery(message);
}
}
}
}
private boolean verifyRequestSignature(byte[] payload, String signature) {
if (!signature.startsWith("sha1="))
return false;
String expected = signature.substring(5);
System.out.println("Expected signature: " + expected); //for debugging purposes
String hashResult = HmacUtils.hmacSha1Hex(APP_SECRET.getBytes(), payload);
System.out.println("Calculated signature: " + hashResult);
if (hashResult.equals(expected)) {
return true;
} else {
return false;
}
}
And this is the Exception handling class:
#ResponseStatus(value=HttpStatus.BAD_REQUEST, reason="Request Signature mismatch")
public class MismatchSignatureException extends RuntimeException {
private String signature;
public MismatchSignatureException(String signature) {
this.signature = signature;
}
#Override
public String getMessage() {
return "Signature mismatch: " + signature;
}