refactor: answerNumber , answer 값 AES 대칭키 적용

cs25-service/src/main/java/com/example/cs25service/domain/quiz/controller/QuizTestController.java

@@ -1,16 +1,21 @@
 package com.example.cs25service.domain.quiz.controller;
 
 import com.example.cs25common.global.dto.ApiResponse;
+import com.example.cs25service.domain.quiz.dto.TodayQuizResponseDto;
 import com.example.cs25service.domain.quiz.service.QuizAccuracyCalculateService;
+import com.example.cs25service.domain.quiz.service.QuizPageService;
 import lombok.RequiredArgsConstructor;
 import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
 @RestController
 @RequiredArgsConstructor
 public class QuizTestController {
 
     private final QuizAccuracyCalculateService accuracyService;
+    private final QuizPageService quizPageService;
 
     @GetMapping("/accuracyTest")
     public ApiResponse<Void> accuracyTest() {
@@ -27,6 +32,17 @@ public ApiResponse<Void> accuracyTest() {
 //        return new ApiResponse<>(200);
 //    }
 
+//    @GetMapping("/test/todayQuiz")
+//    public ApiResponse<TodayQuizResponseDto> showTodayQuizPage(
+//            @RequestParam("quizId") String quizId
+//    ) {
+//
+//        return new ApiResponse<>(
+//                200,
+//                quizPageService.showTodayQuizPage(quizId)
+//        );
+//    }
+
 //    @GetMapping("/test/sse")
 //    public void testSse(HttpServletResponse response) throws IOException {
 //        response.setContentType("text/event-stream");

cs25-service/src/main/java/com/example/cs25service/domain/quiz/service/QuizPageService.java

@@ -8,6 +8,8 @@
 import com.example.cs25service.domain.quiz.dto.TodayQuizResponseDto;
 import java.util.Arrays;
 import java.util.List;
+
+import com.example.cs25service.domain.quiz.util.AesUtil;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
@@ -18,7 +20,7 @@
 public class QuizPageService {
 
     private final QuizRepository quizRepository;
-
+    private final AesUtil aesUtil;
     /**
      * 오늘의 문제를 반환해주는 메서드
      * @param quizId 문제 id
@@ -56,8 +58,8 @@ private TodayQuizResponseDto getMultipleQuiz(Quiz quiz) {
             .choice2(choices.get(1))
             .choice3(choices.get(2))
             .choice4(choices.get(3))
-            .answerNumber(answerNumber)
-            .commentary(quiz.getCommentary())
+            .answerNumber(aesUtil.encrypt(answerNumber))
+            .commentary(aesUtil.encrypt(quiz.getCommentary()))
             .quizType(quiz.getType().name())
             .quizLevel(quiz.getLevel().name())
             .category(getQuizCategory(quiz))
@@ -74,8 +76,8 @@ private TodayQuizResponseDto getDescriptiveQuiz(Quiz quiz) {
         return TodayQuizResponseDto.builder()
             .question(quiz.getQuestion())
             .quizType(quiz.getQuestion())
-            .answer(quiz.getAnswer())
-            .commentary(quiz.getCommentary())
+            .answer(aesUtil.encrypt(quiz.getAnswer()))
+            .commentary(aesUtil.encrypt(quiz.getCommentary()))
             .quizType(quiz.getType().name())
             .quizLevel(quiz.getLevel().name())
             .category(getQuizCategory(quiz))

cs25-service/src/main/java/com/example/cs25service/domain/quiz/util/AesUtil.java

@@ -0,0 +1,72 @@
+package com.example.cs25service.domain.quiz.util;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Component;
+
+import javax.crypto.Cipher;
+import javax.crypto.SecretKey;
+import javax.crypto.spec.IvParameterSpec;
+import javax.crypto.spec.SecretKeySpec;
+import java.nio.charset.StandardCharsets;
+import java.security.SecureRandom;
+import java.util.Base64;
+
+@Component
+public class AesUtil {
+
+    private final String secretKey;
+
+    public AesUtil(@Value("${aes.secret.key}") String secretKey) {
+        this.secretKey = secretKey;
+    }
+
+    private final String ALGORITHM = "AES/CBC/PKCS5Padding";
+
+    private SecretKey getKey() {
+        return new SecretKeySpec(secretKey.getBytes(StandardCharsets.UTF_8), "AES");
+    }
+
+    /** 암호화 */
+    public String encrypt(String plainText) {
+        if (plainText == null) return null;
+        try {
+            Cipher cipher = Cipher.getInstance(ALGORITHM);
+            byte[] iv = new byte[16];
+            new SecureRandom().nextBytes(iv);
+            IvParameterSpec ivSpec = new IvParameterSpec(iv);
+
+            cipher.init(Cipher.ENCRYPT_MODE, getKey(), ivSpec);
+            byte[] encrypted = cipher.doFinal(plainText.getBytes(StandardCharsets.UTF_8));
+
+            // IV와 암호문을 Base64로 함께 인코딩
+            byte[] combined = new byte[iv.length + encrypted.length];
+            System.arraycopy(iv, 0, combined, 0, iv.length);
+            System.arraycopy(encrypted, 0, combined, iv.length, encrypted.length);
+
+            return Base64.getEncoder().encodeToString(combined);
+        } catch (Exception e) {
+            throw new RuntimeException("AES encryption error", e);
+        }
+    }
+
+    /** 복호화 */
+    public String decrypt(String cipherText) {
+        if (cipherText == null) return null;
+        try {
+            byte[] decoded = Base64.getDecoder().decode(cipherText);
+
+            byte[] iv = new byte[16];
+            byte[] encrypted = new byte[decoded.length - 16];
+            System.arraycopy(decoded, 0, iv, 0, iv.length);
+            System.arraycopy(decoded, iv.length, encrypted, 0, encrypted.length);
+
+            Cipher cipher = Cipher.getInstance(ALGORITHM);
+            cipher.init(Cipher.DECRYPT_MODE, getKey(), new IvParameterSpec(iv));
+            byte[] original = cipher.doFinal(encrypted);
+
+            return new String(original, StandardCharsets.UTF_8);
+        } catch (Exception e) {
+            throw new RuntimeException("AES decryption error", e);
+        }
+    }
+}

cs25-service/src/main/resources/application.properties

@@ -137,4 +137,6 @@ server.servlet.session.cookie.secure=true
 FRONT_END_URI=https://cs25.co.kr
 ## JSESSIONID Secure - ??
 #server.servlet.session.cookie.secure=true
-#FRONT_END_URI=http://localhost:5173
+#FRONT_END_URI=http://localhost:5173
+#AES SECRET KEY
+aes.secret.key=${AES_KEY}