Discord oauth2

build.gradle.kts

@@ -13,8 +13,10 @@ dependencies {
 	implementation("org.springframework.boot:spring-boot-starter-data-redis")
 	implementation("org.springframework.boot:spring-boot-starter-data-rest")
 	implementation("org.springframework.boot:spring-boot-starter-oauth2-resource-server")
+	implementation("org.springframework.boot:spring-boot-starter-oauth2-client")
 	implementation("org.springframework.boot:spring-boot-starter-security")
 	implementation("org.springframework.boot:spring-boot-starter-web")
+	implementation("org.mariadb.jdbc:mariadb-java-client:2.7.3")
 	developmentOnly("org.springframework.boot:spring-boot-devtools")
 	testImplementation("org.springframework.boot:spring-boot-starter-test")
 	testImplementation("org.springframework.security:spring-security-test")
@@ -30,7 +32,8 @@ tasks {
 	withType<JavaCompile> {
 		options.encoding = "UTF-8"
 	}
+
 	withType<Test> {
 		useJUnitPlatform()
 	}
-}
+}

src/main/java/net/developerden/backend/controller/InfoController.java

@@ -1,14 +1,21 @@
 package net.developerden.backend.controller;
 
+
+import net.developerden.backend.security.DiscordUser;
 import org.springframework.security.core.annotation.AuthenticationPrincipal;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RestController;
 
 @RestController
 public class InfoController {
 
+    @GetMapping("/user")
+    public String user(@AuthenticationPrincipal DiscordUser principal) {
+        return "Hello, %s (%s)".formatted(principal.fullName(), principal.id());
+    }
+
     @GetMapping("/ping")
     public String ping() {
         return "pong";
     }
-}
+}

src/main/java/net/developerden/backend/security/DiscordUser.java

@@ -0,0 +1,37 @@
+package net.developerden.backend.security;
+
+import org.springframework.security.core.GrantedAuthority;
+import org.springframework.security.oauth2.core.user.OAuth2User;
+
+import java.util.Collection;
+import java.util.Map;
+
+/* TODO we might wanna convert this to a database entity in the future so we can add more data*/
+
+/**
+ * Java representation of all of the data that Discord gives us from the /users/@me API endpoint.
+ */
+public record DiscordUser(String id, String username, String discriminator, String locale) implements OAuth2User {
+    public String fullName() {
+        return username + "#" + discriminator;
+    }
+
+    @Override
+    public Map<String, Object> getAttributes() {
+        return Map.of(
+                "id", id,
+                "username", fullName(),
+                "locale", locale
+        );
+    }
+
+    @Override
+    public Collection<? extends GrantedAuthority> getAuthorities() {
+        return null;
+    }
+
+    @Override
+    public String getName() {
+        return fullName();
+    }
+}

src/main/java/net/developerden/backend/security/DiscordUserService.java

@@ -0,0 +1,37 @@
+package net.developerden.backend.security;
+
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpMethod;
+import org.springframework.http.MediaType;
+import org.springframework.security.oauth2.client.userinfo.OAuth2UserRequest;
+import org.springframework.security.oauth2.client.userinfo.OAuth2UserService;
+import org.springframework.security.oauth2.core.OAuth2AuthenticationException;
+import org.springframework.security.oauth2.core.user.OAuth2User;
+import org.springframework.web.client.RestTemplate;
+
+import java.util.List;
+
+public class DiscordUserService implements OAuth2UserService<OAuth2UserRequest, OAuth2User> {
+    private static final String DISCORD_USERINFO_URI = "https://discord.com/api/users/@me";
+
+
+    @Override
+    public OAuth2User loadUser(OAuth2UserRequest userRequest) throws OAuth2AuthenticationException {
+        final var headers = new HttpHeaders();
+
+        final String authorization = userRequest.getAccessToken().getTokenType().getValue() + " " + userRequest.getAccessToken().getTokenValue();
+        headers.add("Authorization", authorization);
+
+        headers.setAccept(List.of(MediaType.APPLICATION_JSON));
+
+        final var entity = new HttpEntity<>(headers);
+
+        final var user = new RestTemplate()
+                .exchange(DISCORD_USERINFO_URI, HttpMethod.GET,
+                        entity, DiscordUser.class)
+                .getBody();
+
+        return user;
+    }
+}

src/main/java/net/developerden/backend/security/OAuth2LoginConfig.java

@@ -0,0 +1,26 @@
+package net.developerden.backend.security;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.security.config.Customizer;
+import org.springframework.security.config.annotation.web.builders.HttpSecurity;
+import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
+import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
+import org.springframework.security.oauth2.core.user.DefaultOAuth2User;
+import org.springframework.security.web.authentication.HttpStatusEntryPoint;
+
+import java.util.Collections;
+
+@EnableWebSecurity
+public class OAuth2LoginConfig extends WebSecurityConfigurerAdapter {
+    @Override
+    protected void configure(HttpSecurity http) throws Exception {
+        http.authorizeRequests(a ->
+                a.antMatchers("/", "/error").permitAll()
+                        .anyRequest().authenticated()
+        )
+
+                .oauth2Login()
+                .userInfoEndpoint()
+                .userService(new DiscordUserService());
+    }
+}

src/main/resources/application.yml

@@ -0,0 +1,26 @@
+spring:
+  jpa:
+    hibernate:
+      ddl-auto: none
+    show-sql: true
+  datasource:
+    url: jdbc:mariadb://${DDB_DATABASE_URL}:3306/${DDB_DATABASE_NAME}
+    username: ${DDB_DATABASE_USER}
+    password: ${DDB_DATABASE_PASSWORD}
+    driver-class-name: org.mariadb.jdbc.Driver
+  security:
+    oauth2:
+      client:
+        registration:
+          discord:
+            clientId: ${DDB_CLIENT_ID}
+            clientSecret: ${DDB_CLIENT_SECRET}
+            authorizationGrantType: authorization_code
+            redirectUri: "{baseUrl}/login/oauth2/code/discord"
+            scope: identify
+        provider:
+          discord:
+            authorizationUri: https://discord.com/api/oauth2/authorize
+            tokenUri: https://discord.com/api/oauth2/token
+
+

src/main/resources/static/index.html

@@ -0,0 +1,16 @@
+<!doctype html>
+<html lang="en">
+<head>
+    <meta charset="utf-8"/>
+    <meta http-equiv="X-UA-Compatible" content="IE=edge"/>
+    <title>Demo</title>
+    <meta name="description" content=""/>
+    <meta name="viewport" content="width=device-width"/>
+    <base href="/"/>
+</head>
+<body>
+<h1>Demo</h1>
+<div class="container"></div>
+</body>
+<a href="/oauth2/authorization/discord">Login</a>
+</html>