Spring Boot HTTPS with self-signed certificate - spring-boot

Question

I'm making a Slack app with Spring Boot and have created an endpoint for Slack to send payloads to. Since Slack runs over HTTPS I have had to enable HTTPS by generating a self-signed certificate purely for testing purposes. I updated my application.yml with the following:
server:
port: 3000
ssl:
enabled: true
key-store: classpath:cert.p12
key-store-password: my_password
key-store-type: pkcs12
When I try to access the endpoint in my browser I get the error NET::ERR_CERT_INVALID. I then try curl on my endpoint and get the error:
curl: (60) SSL certificate problem: self signed certificate
curl failed to verify the legitimacy of the server and therefore could not
establish a secure connection to it.
My Slack app doesn't seem to be able to reach the endpoint either, giving an error /hello failed with the error "ssl_cacert" when I try a slash command.
Is there something else I need to do when setting up a self signed certificate? I'm aware this is unsafe in practice and therefore may be the root of these errors.
Many thanks for the help!

Answer 1

First of all, you have to set up your backend correctly:
Add dependency:
implementation 'org.apache.httpcomponents:httpclient:4.5'
Provide RestTemplate bean:
#Bean
private RestTemplate restTemplate() {
SSLContext sslContext = buildSslContext();
SSLConnectionSocketFactory socketFactory = new SSLConnectionSocketFactory(sslContext);
HttpClient httpClient = HttpClients.custom()
.setSSLSocketFactory(socketFactory)
.build();
HttpComponentsClientHttpRequestFactory factory = new HttpComponentsClientHttpRequestFactory(httpClient);
return new RestTemplate(factory);
}
private SSLContext buildSslContext() {
try {
char[] keyStorePassword = sslProperties.getKeyStorePassword();
return new SSLContextBuilder()
.loadKeyMaterial(
KeyStore.getInstance(new File(sslProperties.getKeyStore()), keyStorePassword),
keyStorePassword
).build();
} catch (Exception ex) {
throw new IllegalStateException("Unable to instantiate SSL context", ex);
} finally {
sslProperties.setKeyStorePassword(null);
sslProperties.setTrustStorePassword(null);
}
}
Provide required SSL properties in your application.properties or application.yaml file:
server:
ssl:
enabled: true
key-store: /path/to/key.keystore
key-store-password: password
key-alias: alias
trust-store: /path/to/truststore
trust-store-password: password
That's it. Now you can see your Tomcat is starting on 8080 (or another port) (https).
Alternatively, you can use my spring boot starter