Enable https in Spring Boot

In this article of Spring Boot tutorial, we will see how to enable HTTPS in Spring Boot application. We will generate and configure the self-signed certificate for this example to enable HTTPS in Spring Boot application.

 

1. Create Self Signed SSL Certificate

In this article, we will use Java keytool to generate the self-signed SSL certificate. Other options is to get this certificate from a certification authority. For the production environment, always get your SSL certificate from these certifications authority (CA) also known as CA. To generate the SSL certificate, run the keytool -genkey command with the following parameters from the command prompt.

keytool -genkeypair -alias javadevjournal -keyalg RSA -keysize 2048 -storetype PKCS12 -keystore javadevjournal.p12 -validity 3650

On running above command, it will ask for certain information. This is how the command line will look like:

1.1 Keytool Command

Before moving ahead let’s understand above command:

• -genkeypair generates a key pair (a public key and a private key).
• -alias javadevjournal shows the alias of the certificate used by SSL/TLS layer.
• -keyalg RSA -keysize 2048 -validity 3650–crypto algorithm, keysize and certificate validity.
• -keystore javadevjournal.p12–actual keystore where the certificate and public/private key stored.

We have the option to generate the following certificate while working on self signed SSL certificate:

1. JKS – Java KeyStore, limited to the Java environment only.
2. PKCS12 – Public Key Cryptographic Standards is a password-protected format that can contain multiple certificates and keys; it’s an industry-wide used format.

 

1.2 Certificate Details

To view the details of the keystore, use the keytool -list command:

keytool -list -keystore javadevjournal.p12

You will have similar output on the console:

 

2. Enabling HTTPS in Spring Boot

Create a new Spring Boot project to test our SSL certification. Spring Boott provides the option to enable HTTPS using the application.properties file. To configure SSL, use the server.ssl.*. properties in application.properties Read our article to 

# The format used for the keystore. for JKS, set it as JKS server.ssl.key-store-type=PKCS12 # The path to the keystore containing the certificate server.ssl.key-store=classpath:keystore/javadevjournal.p12 # The password used to generate the certificate server.ssl.key-store-password=use the same password which we added during certificate creation # The alias mapped to the certificate server.ssl.key-alias=javadevjournal # Run Spring Boot on HTTPS only server.port=8443

[pullquote align=”normal”]We’ll copy the file named “javadevjournal.p12″ into the “src/main/resources/keystore” directory. [/pullquote]

With above configuration, we have enabled HTTPS in Spring Boot application. Our application is ready to accept and server over HTTPS. Let’s create a simple REST controller to test our application.

 

3. REST Controller

To test our application, let’s create a simple REST controller.

package com.javadevjournal.controller; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; @RestController public class SSLTestController { @GetMapping(value = "/ssl-test") public String greeting(){ return "Self Signed SSL is Working!!"; } }

 

4. SSL in Action

To see our SSL configuration in action, build and deploy our Spring Boot application. You can also run your application through your IDE for testing purpose. Once your application is up and running Go to https://localhost:8443/ssl-test and you will get a browser warning since it is not issued by a trusted certificate authorities, add the exception to the browser and you will get a response from HTTPS server just created by you.

[pullquote align=”normal”]Configurations!! You are have enabled HTTPS in Spring Boot application [/pullquote]

 

5. Redirect HTTP to HTTPS

This step becomes important if you qualify under following categories:

1. You want to make your application accessible over HTTP but want to redirect to HTTPS.
2. You are moving away from HTTP to HTTPS and want to make sure all HTTP requests redirects to HTTPS.

To handle this, add the below code to your configuration class:

@Bean public ServletWebServerFactory servletContainer() {	TomcatServletWebServerFactory tomcat = new TomcatServletWebServerFactory() {@Override	protected void postProcessContext(Context context) {	SecurityConstraint securityConstraint = new SecurityConstraint();	securityConstraint.setUserConstraint("CONFIDENTIAL");	SecurityCollection collection = new SecurityCollection();	collection.addPattern("/*");	securityConstraint.addCollection(collection);	context.addConstraint(securityConstraint);	}	};	tomcat.addAdditionalTomcatConnectors(redirectConnector());	return tomcat; } private Connector redirectConnector() {	Connector connector = new Connector("org.apache.coyote.http11.Http11NioProtocol");	connector.setScheme("http");	connector.setPort(8080);	connector.setSecure(false);	connector.setRedirectPort(8443);	return connector; }

If you are using Spring Boot < 2.0, above code will not work for you. For Spring Boot lower version, use the following code:

@Bean public EmbeddedServletContainerFactory servletContainer() {	TomcatEmbeddedServletContainerFactory tomcat = new TomcatEmbeddedServletContainerFactory() {@Override	protected void postProcessContext(Context context) {	SecurityConstraint securityConstraint = new SecurityConstraint();	securityConstraint.setUserConstraint("CONFIDENTIAL");	SecurityCollection collection = new SecurityCollection();	collection.addPattern("/*");	securityConstraint.addCollection(collection);	context.addConstraint(securityConstraint);	}	};	tomcat.addAdditionalTomcatConnectors(redirectConnector());	return tomcat; } private Connector redirectConnector() {	Connector connector = new Connector("org.apache.coyote.http11.Http11NioProtocol");	connector.setScheme("http");	connector.setPort(8080);	connector.setSecure(false);	connector.setRedirectPort(8443);	return connector; }

 

Summary

In this article, we saw how to create a self-signed SSL certificate and enable HTTPS in Spring Boot application. We also learned the steps and configuration to redirect HTTP traffic to HTTPS. Source code for this article is available over GitHub